Anesthetics - Critical Care Flashcards
A
57-year-old woman undergoes right mastectomy with immediate deep inferior epigastric perforator flap breast reconstruction for treatment of right breast cancer. BMI is 28 kg/m2. Preoperative Caprini RAM score is 6. Perioperative pneumatic compression boots and low-dose heparin are initiated. On postoperative day 2, the patient becomes tachycardic after walking to the bathroom. Resting heart rate is 110/bpm, blood pressure is 118/40 mm Hg, respiratory rate is 24/min, and pulse oximetry is 93% on 6 L nasal cannula oxygen supplementation. Urine output is 50 mL per hour over the past 8 hours. Which of the following is the most likely diagnosis?
A) Active bleeding
B) Anxiety
C) Caffeine withdrawal
D) Hypovolemia
E) Pulmonary embolism
The correct response is Option E.
The patient most likely has a pulmonary embolism. Pulmonary embolisms are rare but deadly complications following microsurgical breast reconstruction, and they often present with tachycardia alone (with or without hypoxia). The patient is receiving 6 L nasal cannula oxygen supplementation, so hypoxia is difficult to assess. Anxiety would commonly present as tachycardia with hypertension. Hypovolemia and active bleeding would commonly present with tachycardia with hypotension and decreased urine output. Caffeine withdrawal would commonly present with a headache.
A 43-year-old woman is scheduled to undergo bilateral tissue expander-based breast reconstruction. Preoperative pectoral nerve 1 and 2 blocks with liposomal bupivacaine with ultrasound guidance is performed. An image is shown. When performing pectoral nerve 1 block in this patient, which of the following is the most appropriate location for infiltration of the local anesthetic?
A) Between the breast parenchyma and pectoralis major
B) Between the pectoralis major and pectoralis minor
C) Between the pectoralis minor and the serratus anterior
D) Between the serratus anterior and the latissimus dorsi
The correct response is Option B.
The pectoral nerve (PECS) 1 and 2 anesthetic blocks have become increasingly common methods for regional anesthesia to decrease postoperative pain in many early recovery after surgery (ERAS) protocols. The PECS blocks are thoracic regional fascial plane blocks that typically require ultrasound guidance for proper infiltration of the anesthetic between the muscles of the thoracic wall.
A PECS 1 block is performed between the pectoralis major and pectoralis minor muscles and anesthetizes the lateral and medial pectoral nerves. A PECS 2 block, in addition to the PECS 1 block, involves an additional injection of anesthetic between the pectoralis minor and serratus anterior muscles and blocks the intercostal and intercostobrachial nerves. The serratus plane block is another thoracic regional fascial plane block requiring injection of local anesthetic between the serratus anterior and latissimus dorsi muscles in order to block the long thoracic and thoracodorsal nerves.
A 24-year-old man with a history of opioid use disorder is scheduled to undergo closed reduction and percutaneous Kirschner wire fixation of a right fifth metacarpal fracture. The patient is placed on an enhanced recovery after surgery (ERAS) protocol. Which of the following medications used to treat pain binds to voltage-gated calcium channels?
A) Acetaminophen
B) Gabapentin
C) Ketamine
D) Lidocaine
E) Oxycodone
The correct response is Option B.
Gabapentin is a structural analogue of the neurotransmitter gamma-aminobutyric acid and high affinity to voltage-gated calcium channels at presynaptic terminals of hyperexcited neurons through reduction in depolarization-influx of calcium required for release of excitatory neurotransmitters, including glutamate, noradrenaline, dopamine, and serotonin. The exact nature of its analgesic effect is incompletely understood. Contemporary evidence demonstrates that perioperative administration in conjunction with an ERAS protocol is associated with a significant reduction in postoperative opioid use.
Lidocaine is an amide local anesthetic that decreases the excitation threshold of nociceptive afferent neurons by decreasing neuronal membrane permeability through voltage-gated sodium channels. The inhibition of neuronal depolarization results in blockade of pain transmission.
Oxycodone is a semi-synthetic opioid that is primarily the mu-opioid receptor agonist that opens calcium-dependent inward-rectifying potassium channels, which causes hyperpolarization and reduced excitability of neuronal ascending pain pathways.
Acetaminophen was previously believed to exert its analgesic effect by inhibiting cyclooxygenase enzymes 1 and 2. Recent investigations demonstrated that the main analgesic mechanism is the metabolite p-aminophenol, which crosses the blood-brain barrier and is converted to N-acylphenolamine (AM404). AM404 then acts on the transient receptor potential vanilloid subtype 1 (TRPV1) and cannabinoid 1 receptors in the brain and terminals of C-fibers in the spinal dorsal horn. Both the brain and spinal dorsal horn are critical to pain pathways and modulate nociceptive transmission. Therefore, acetaminophen induces analgesia by acting on the brain and spinal cord.
Ketamine is a noncompetitive antagonist to the N-methyl-d-aspartate (NMDA) receptors. The NMDA receptor is involved in the amplification of pain signals, central sensitization, and opioid tolerance. The ketamine molecule is hydrophilic and lipophilic, allowing it to cross the blood-brain barrier to exert its NMDA antagonist effects in the brain and spinal cord.
A 65-year-old man undergoes hemimandibulectomy and reconstruction with a fibular flap for oral squamous cell carcinoma. On postoperative day 4, the patient develops a cough and feels ill. Temperature is 39.4°C (102°F), blood pressure is 80/40 mmHg, heart rate is 120 bpm, and respiratory rate is 32/min. On physical examination, the surgical sites are unremarkable. Intravenous fluid resuscitation is promptly initiated. Blood cultures are collected and broad-spectrum antibiotics are administered. Which of the following is the most appropriate next step in management?
A) Administering additional fluid resuscitation with hydroxyethyl starch
B) Initiating low-dose dopamine for renal protection
C) Measuring lactate level
D) Narrowing antimicrobial therapy based on culture results
E) Placing a pulmonary artery catheter
The correct response is Option C.
Measuring lactate level is the most appropriate next step in management of this patient who is developing sepsis/septic shock in the postoperative period.
In the 2018 update of the 2016 Surviving Sepsis Campaign guidelines, an Hour-1 Bundle was modified to reflect the need to begin resuscitation and management of patients with sepsis and septic shock immediately upon presentation. The Hour-1 bundle includes:
Measuring lactate level. To be re-measured in 2 to 4 hours if initial lactate is > 2 mmol/L
Obtaining blood cultures prior to administration of antibiotics
Administering broad-spectrum antibiotics
Rapidly administering 30 mL/kg crystalloid for hypotension or lactate ≥ 4 mmol/L
Initiating vasopressors if patient is hypotensive during or after fluid resuscitation to maintain MAP ≥ 65 mmHg
Serum lactate levels, although not a direct measure, can serve as a surrogate of tissue hypoperfusion. Randomized controlled trials have demonstrated a significant reduction in mortality when lactate-guided resuscitation is employed.
The 2016 Surviving Sepsis Campaign recommended against using low-dose dopamine for renal protection (lack of evidence supporting its efficacy), against providing fluid resuscitation with hydroxyethyl starch (higher risk for death compared with other fluids), and against routine use of pulmonary artery catheters (lack of evidence in improving septic patient outcomes). It does recommend narrowing of antimicrobial therapy based on culture results, but these would not be available in this patient’s early phase of management.
A 42-year-old man presents with partial degloving injury of the right leg and fracture of the pelvis sustained during a motorcycle collision 2 weeks ago. Medical history includes factor V Leiden. BMI is 31.1 kg/m2. Skin graft reconstruction of the degloving injury of the leg is planned. According to the Caprini Risk Assessment Model (2005), which of the following conditions in this patient represents the greatest risk for perioperative venous thromboembolism?
A) Age
B) BMI greater than 25 kg/m2
C) Major surgery (greater than 45 minutes in duration)
D) Pelvic fracture
E) Positive factor V Leiden
The correct response is Option D.
The ASPS Venous Thromboembolism Task Force Report includes recommendations for risk stratification based on the Caprini Risk Assessment Model (RAM), which has been widely validated in the scientific literature for evaluation of surgical patients. The 2005 model in particular is most applicable to plastic surgery. This model awards a score based on various weighted patient risk factors, with venous thromboembolism (VTE) risk increasing as the score increases. The literature suggests that patients with a Caprini RAM score less than 8, who were not provided chemoprophylaxis, experienced VTE at a rate of 11.3%.
The Caprini RAM score for this patient is 12. Age 41 to 60 years is 1 point. BMI greater than 25 kg/m2 is 1 point. Major surgery (longer than 45 minutes) is 2 points. Positive factor V Leiden, an inheritable mutation in factor V protein, which is involved in the blood clotting cascade, is 3 points. Hip, pelvis, or leg fracture within the past month is 5 points. Based on this risk stratification tool, the surgeon “should strongly consider the option to use extended low molecular weight heparin postoperative prophylaxis” in this patient.
According to the Malignant Hyperthermia Association of the United States guidelines, which of the following intravenous agents should be avoided during the acute resuscitation phase of malignant hyperthermia, following dantrolene administration, when treating subsequent cardiac dysrhythmias?
A) Dextrose 50% solution
B) Epinephrine
C) Lidocaine
D) Metoprolol
E) Verapamil
The correct response is Option E.
Malignant hyperthermia (MH) is a disturbance of calcium channel homeostasis, causing unregulated calcium release from sarcoplasmic reticulum. The coadministration of dantrolene used during resuscitation and an intravenous calcium channel blocker is contraindicated, since both verapamil and diltiazem have been associated with life-threatening hyperkalemia in this setting. The other agents listed (metoprolol, lidocaine, epinephrine, and dextrose 50%) may be used as needed during advanced cardiovascular life support protocols or for the treatment of hyperkalemia. MH is a pharmacogenetic disorder triggered in genetically susceptible individuals by volatile anesthetic gases and succinylcholine. It has autosomal dominant inheritance. Dantrolene is the only treatment for a MH crisis, and a newer formulation has faster administration than traditional preparations. The resuscitation poster for MH should be in every operating room facility and is mandated by the American Association for Accreditation of Ambulatory Surgical Facilities (AAAASF) standards. Their phone number is 1-800-MH-HYPER.
A 35-year-old woman is interested in a tummy tuck and liposuction of the flanks and mid back. She does not smoke cigarettes, can climb two flights of stairs without shortness of breath or chest pain, and takes medication for hypothyroidism, which is well-controlled. Height is 5 ft 6 in (167 cm) and weight is 260 lbs (118 kg). BMI is 42 kg/m2. She is otherwise healthy. On the basis of this patient’s history, which of the following is the most appropriate American Society of Anesthesiologists (ASA) physical status classification?
A) ASA I
B) ASA II
C) ASA III
D) ASA IV
E) ASA V
The correct response is Option C.
This patient is classified as ASA III, on the basis of a BMI greater than 40 kg/m2. Thus, she may not be a candidate for surgical facilities that are restricted to ASA I or II cases, like many office-based surgical facilities. Other examples of health factors that potentially classify a patient as ASA III (or higher) include: history of transient ischemic attack, stroke, poorly controlled diabetes mellitus or hypertension, chronic obstructive pulmonary disease, active hepatitis, alcohol dependence or abuse, implanted pacemaker, moderate decrease of ejection fraction, end-stage kidney disease undergoing regularly scheduled dialysis, percutaneous coronary angioplasty within 60 weeks, and history of myocardial infarction or stents for coronary artery disease more than 3 months ago.
A 78-year-old man who was recently diagnosed with low rectal cancer presents to the office for evaluation. The patient is accompanied by his daughter, who fills out all the questionnaires for him. Medical history includes hypertension, osteoarthritis, and bilateral knee replacements 20 years ago. Vital signs are within normal range. BMI is 21.5 kg/m2. He ambulates with a walker. Physical examination is otherwise unremarkable. An abdominoperineal resection and perineal reconstruction are planned. Obtaining which of the following is the most appropriate next step in assessing this patient’s risk for perioperative complications?
A) APACHE II score
B) FEV1/FVC ratio
C) Frailty index
D) Liver function tests
E) Sequential Organ Failure Assessment (SOFA) score
The correct response is Option C.
Obtaining a frailty score would help providers assess the perioperative risk for this elderly patient with limited ambulation and possible cognitive impairment who is about to undergo a significant colorectal and reconstructive operation.
Frailty is a state of functional compromise in an elderly patient, which may include declined ability to maintain homeostasis, loss of physiological reserve, and increased vulnerability to adverse outcomes in the perioperative period.
Chronological age alone has been found to be a poor predictor of cancer and/or surgery tolerance by elderly patients. This subgroup of surgical patients has been rapidly increasing in number due to overall aging of the US population and can be quite heterogeneous when it comes to individual health status. Therefore, preoperative evaluation of elderly patients should include medical comorbidities and baseline functional status.
Several frailty scoring systems have been described, including the Phenotype Model, Cumulative Deficit Model, Comprehensive Geriatric Assessment, Risk Analysis Index, Charlson Comorbidity Index, Hopkins Score, and Frailty Index, along with its 11- and 5-item modified/simplified versions. Scored variables include physical characteristics (unintentional weight loss, slow gait, weak grip strength, etc.), medical history (stroke with deficit, myocardial infarction, congestive heart failure, etc.), and laboratory results (kidney function, nutrition, etc.).
Higher frailty scores have been associated with higher risk for in-hospital complications, longer hospital stay, discharge disposition to a skilled nursing facility, increased postoperative complications, and decreased postoperative survival at 30, 180, and 365 days.
Liver function may not be indicated in this patient without any history of abnormal bleeding or jaundice or signs of liver disease. FEV1 (forced expiratory volume) to FVC (forced vital capacity) ratio is used to monitor airway flow and assess response to therapy in patients with asthma. APACHE (Acute Physiology and Chronic Health Evaluation) II and SOFA (Sequential Organ Failure Assessment) are used to grade severity of illness in critically ill patients and predict clinical outcomes in the ICU setting.
A 42-year-old woman is scheduled for abdominoplasty, repair of diastasis recti abdominis, and incisional herniorrhaphy. At the start of the operation, 20 mL of 1% lidocaine with epinephrine 1:100,000 is injected into the lower abdominal incision. After incisional herniorrhaphy is completed, the general surgeon plans to inject liposomal bupivacaine into the lower abdominal hernia repair. Which of the following is the most appropriate recommendation regarding the injection of liposomal bupivacaine after lidocaine injection?
A) Do not use liposomal bupivacaine after lidocaine is used
B) Wait at least 20 minutes before injecting liposomal bupivacaine
C) Wait at least 60 minutes before injecting liposomal bupivacaine
D) Wait at least 90 minutes before injecting liposomal bupivacaine
E) There are no restrictions
The correct response is Option B.
Wait at least 20 minutes before injecting liposomal bupivacaine. Liposomal bupivacaine (Exparel), is a long-acting (approximately 72 hours) local anesthetic that is an extended-release multivesicular liposomal version of bupivacaine. It has been shown that this drug can decrease the need for opiates in the postoperative period.
Nonbupivacaine anesthetics, including lidocaine, when mixed with liposomal bupivacaine may cause an immediate release of bupivacaine, potentially causing an overdose. For this reason, lidocaine and liposomal bupivacaine should not be mixed together. Administration of liposomal bupivacaine may follow the administration of lidocaine after a delay of 20 minutes or more. Administration of liposomal bupivacaine results in systemic plasma concentrations that can persist for 96 hours after local infiltration. That said, it is recommended that the use of local anesthetics be avoided within 96 hours following administration of liposomal bupivacaine. The other choices are incorrect because they do not conform to the recommendations and pharmacology of the involved medication.
A 55-year-old man undergoing excision of a soft-tissue mass of the left thigh develops malignant hyperthermia shortly after induction of general anesthesia. The surgical procedure is promptly aborted, and the patient is successfully treated. Six months later, he returns for another attempt at excising the mass. The use of which of the following anesthetic agents is most appropriate in this case?
A) Ether
B) Halothane
C) Propofol
D) Sevoflurane
E) Succinylcholine
The correct response is Option C.
Lidocaine and all other local anesthetics are considered safe to be used in patients who are susceptible to malignant hyperthermia.
Volatile anesthetic agents (halothane, sevoflurane, ether) and depolarizing muscle relaxants (succinylcholine) are considered potential triggers of malignant hyperthermia and, therefore, should be avoided in susceptible individuals.
Other anesthetic agents that are considered safe to be used in patients susceptible to malignant hyperthermia include:
nonvolatile general anesthetics: nitrous oxide
opioids: morphine, fentanyl, alfentanil, hydromorphone, meperidine, naloxone
barbiturates and intravenous anesthetics: thiopental, propofol, etomidate
nondepolarizing muscle relaxants: pancuronium, atracurium, rocuronium
benzodiazepines: lorazepam (Ativan), midazolam (Versed), klonopin
Dozens of genetic mutations have been associated with susceptibility to malignant hyperthermia, which is generally inherited in an autosomal dominant pattern
An otherwise healthy 45-year-old woman presents for abdominoplasty. Administration of liposomal bupivacaine for postoperative pain control is planned. Which of the following is the maximum dose of liposomal bupivacaine that can be administered in a single dose in this patient?
A) 50 mg
B) 133 mg
C) 200 mg
D) 266 mg
E) 399 mg
The correct response is Option D.
Liposomal bupivacaine is frequently used to manage postoperative pain. The mechanism of action is bupivacaine loads into multivesicular liposomes, thus allowing for slow release of bupivacaine. The potential efficacy of liposomal bupivacaine can last between 72 to 96 hours. Thus, studies have shown that administration of liposomal bupivacaine can decrease postoperative pain and also decrease the usage of opioids. The administration of liposomal bupivacaine is not weight-dependent, and the maximum dose recommended is a single administration of 266 mg or 20 mL. To cover a larger area, volume expansion with saline or bupivacaine can be used by dilution of the 266 mg; however, it is not recommended to exceed this dose.
A 22-lb (10-kg), 8-month-old infant is undergoing cranial vault reconstruction. The anesthesiologist informs the surgeon that the estimated blood loss is 150 mL. Approximately which of the following percentages of this patient’s circulating blood volume has been lost?
A) 10%
B) 20%
C) 30%
D) 40%
E) 50%
The correct response is Option B.
In infants, the formula used for estimated circulating blood volume is 75 to 80 mL per kg of body weight. This infant’s estimated circulating volume is 750 mL total. When performing surgery with blood loss that is large relative to circulating volume, blood loss control and blood replacement need to be watched carefully.
Estimated circulating blood volume in a 154-lb (70-kg) adult is 5.5 L
For neonates the formula is increased to 85 to 90 mL/kg
For infants the formula is 75 to 80 mL/kg
For children the formula is decreased to 70 to 75 mL/kg
The surgeon should be aware when working on infants of the changing estimate of circulating blood volume based on weight. A reference for a recent nomogram for prediction of hemoglobin and hematocrit shifts after blood loss and resuscitation is included in the resources, as well as classic papers on fluids in pediatric patients and estimations of estimated circulating volume.
A 63-year-old woman with a history of breast cancer presents for delayed reconstruction with bilateral latissimus dorsi muscle flaps. Medical history includes coronary artery disease, hypertension, and rheumatoid arthritis. Current medications include aspirin, propranolol, and prednisone, which she has taken for 8 years. In preparation for surgery, prednisone is discontinued 6 weeks before and aspirin is discontinued 1 week before surgery. The surgical procedure is uneventful. In the PACU, her heart rate is 115 bpm and blood pressure is 80/40 mmHg. Physical examination shows no signs of hematoma. A total of 3 L of intravenous fluid boluses are administered, with no hemodynamic improvement. Chest x-ray, ECG, hematocrit and serum electrolytes, and troponins are normal. Despite increasing doses of vasopressors during the next 2 hours, the patient remains hypotensive. Administration of which of the following is the most appropriate next step in management?
A) Dantrolene
B) Desmopressin (DDAVP)
C) Hydrocortisone
D) Insulin and dextrose
E) Labetalol
The correct response is Option C.
The most appropriate next step in managing this patient with otherwise unexplainable refractory hypotension and a recent history of long-term steroid use is intravenous administration of hydrocortisone, with the presumptive diagnosis of adrenal crisis.
The first case reports of surgery-induced acute adrenal insufficiency in patients on long-term steroid therapy were published in the early 1950s, just a few years after the release of oral cortisone in 1949. Today, over 6 decades later, significant controversy remains in the prevention, diagnosis, and treatment of this disease, despite its fatality if not appropriately prevented or managed.
Clinical signs of acute adrenal insufficiency, or adrenal crisis, include hypotension, hypoglycemia, dehydration, altered mental status, and hyponatremia, which can quickly progress to fatal hemodynamic collapse.
Prescribed steroid therapy (PST) can cause suppression of the hypothalamo–pituitary–adrenal (HPA) axis, placing these patients at risk for acute adrenal insufficiency as a consequence of surgical stress. Prednisone doses ? 5 mg/day (or hydrocortisone-equivalent dose) in adults via any route of administration (oral, inhaled, topical, intranasal, intra-articular) are sufficient to raise concern. There is no consensus on the minimal duration of PST to place patients at risk for an adrenal crisis, but 3 weeks is commonly cited. The risk may remain for up to 1 year after discontinuation of PST.
There seems to exist no consensus on the preoperative evaluation of patients at risk. Laboratory evaluation of their HPA axis is possible (e.g., ACTH challenge), but results correlate poorly with actual incidence of adrenal crisis. There is also no consensus on a prophylactic steroid regimen for patients at risk, although a recent trend away from the perioperative administration of high-dose steroids purely as prophylaxis can be observed, particularly in the inflammatory bowel disease literature.
Apart from all the controversy, at least a couple of principles related to this disease seem to be universally accepted: 1) a high degree of suspicion should be exercised when encountering unexplained refractory hemodynamic instability in a patient on PST subjected to stress by surgery or illness; 2) in such a case, preference should be given to prompt administration of rescue steroids, considering the expected mortality of untreated crises and the lack of evidence of long-term adverse consequences from short-term steroid administration.
None of the other drugs listed are directly pertinent to the management of the adrenal crisis in this patient. Desmopressin (DDAVP) causes the release of von Willebrand factor from platelets and endothelial cells. It is used in cases of factor VIII or von Willebrand factor deficiency. Insulin and dextrose solutions are used to shift potassium intracellularly in the treatment of hyperkalemia. Dantrolene is used in the treatment of malignant hyperthermia. Labetalol, a beta-adrenergic blocker, would probably worsen the patient’s hypotension.
Tranexamic acid inhibits which of the following enzymatic conversions?
A) Factor VII to factor VIIa
B) Factor X to factor Xa
C) Fibrinogen to fibrin
D) Plasminogen to plasmin
E) Prothrombin to thrombin
The correct response is Option D.
Tranexamic acid (TXA) has seen an expanding role in plastic surgery in recent years to decrease blood loss. Its mechanism of action is to inhibit the conversion of plasminogen to plasmin, which in turn inhibits the fibrinolytic pathway (clot degradation). All of the other options are steps involved in the clotting cascade, which are required for hemostasis (clot formation). TXA does not have an effect on any of those steps.
A 37-year-old woman undergoes breast augmentation and lipo-abdominoplasty with an overnight stay. She has no history of complicated or drug-resistant infections and no known drug allergies. To decrease the risk for surgical site infection, which of the following is the most appropriate antibiotic, dosing, and duration for this patient?
A) Cefazolin, first and only dose within 1 hour of incision
B) Cefazolin, first dose within 1 hour of surgery, continue for 23 hours postoperatively
C) Cefuroxime, first and only dose within 1 hour of incision
D) Cefuroxime, first dose within 1 hour of incision, continue for 23 hours postoperatively
E) No antibiotic therapy necessary
The correct response is Option A.
Due to growing concern over antibiotic misuse, patterns of antibiotic prescribing and adherence to guidelines must be surveyed. In 2003, Lyle et al. examined the prescribing practices of plastic surgeons with respect to different surgical procedures and compared with previous surveys. Authors found that surgeons were prescribing prophylactic antibiotics in more than 70% of cases for all procedures with the exception of blepharoplasty and chemical peel.
Though the evidence supports judicious antibiotic prescribing and consistently denounces long-term antibiotic therapy, surgeons often fail to adhere to these guidelines, in favor of longer duration antibiotic prophylaxis.
Ariyan et al. published an evidence-based consensus statement in 2015, detailing antibiotic prophylaxis to prevent surgical site infections (SSI) in plastic surgery. They performed a meta-analysis of the best available evidence across common plastic surgery procedures.
With respect to cosmetic breast and body surgery, authors analyzed data from 12 breast studies (three RCTs, nine non-RCTs) and 1 abdominal study (non-RCT). They concluded that the meta-analysis of the RCTs in clean breast surgery showed a significant reduction in risk for SSI with antibiotic prophylaxis versus control (2.5 vs 11.4%; OR, 0.16; 95% CT, 0.04 to 0.061; p = 0.01). When combined with non-RCTs, there was still a significant risk reduction (3.8 vs 6.7%; OR, 0.50; 95% CI, 0.26 to 0.94; p = 0.03).
With respect to abdominoplasty, the authors of the consensus statement reported the results of a pseudorandomized study in which antibiotic prophylaxis did not result in a significant reduction in SSI (6.5 vs 13.0%; OR 0.47; 95% CI, 0.18 to 1.23; p = 0.12).
Assuming that there is no contraindication, Cefazolin is generally recommended as a first-line, prophylactic antibiotic for clean plastic surgery procedures. CDC guidelines recommend antibiotic administration between 30 to 60 minutes from the initial incision. Two grams of cefazolin is indicated for patients less than 120 kg, and 3 grams is recommended for those over 120 kg.
Current data do not support prescribing additional antibiotics beyond a single preoperative dose.
A 24-year-old woman underwent uneventful cosmetic bilateral breast augmentation. One day postoperatively, the patient reports difficulty urinating with pubic fullness and discomfort. Which of the following is the most likely cause of this patient’s symptoms?
A) Acute tubular necrosis
B) Adverse effect of anesthesia
C) Inadequate resuscitation
D) Poor pain control
E) Urinary tract infection
The correct response is Option B.
Postoperative urinary retention (POUR) is a common postoperative complication that most often arises secondary to the general anesthesia given during surgery. The prevalence of POUR has been cited as up to 70% in the literature. The anesthetic medications used during the procedure can suppress micturition control and reflexes at the level of the central nervous system and peripheral nervous system while also acting as a smooth muscle relaxant that decreases bladder contractility. Management of POUR can be conservative, including ambulation and cessation of systemic analgesics, or invasive with either intermittent or indwelling catheter placement.
Correction of poor pain control with additional narcotic medications would likely worsen POUR. Urinary tract infection, while a possibility, would be associated with pain and burning during urination as opposed to pubic fullness and discomfort. Inadequate resuscitation would present with a lack of bladder fullness associated with oliguria. Acute tubular necrosis is associated with renal failure which this patient is unlikely to have.
A 42-year-old woman undergoes deep inferior epigastric artery perforator flap breast reconstruction. An ultrasound-guided transversus abdominis plane regional block with liposomal bupivacaine is planned. The ultrasound probe is placed directly over the abdominal wall musculature in the anterior axillary line. The sonographic image is shown. Injection at which of the following levels is most appropriate?
The correct response is Option C.
Transversus abdominis plane regional anesthetic blocks have been shown to decrease narcotic consumption and abdominal pain following abdominal-based microsurgical breast reconstruction. The sensory nerves to the anterior abdominal wall run in the interfascial plane between the internal oblique and transversus abdominis muscles. A successful regional block depends on precise identification of the proper plane for the injection. The arrow indicated by letter C represents the transversus abdominis plane.
The arrow indicated by letter A indicates the interfascial plane between the internal and external oblique muscles.
The arrow indicated by letter B indicates the body of the internal oblique muscle.
The arrow indicated by letter D indicates the peritoneum.
The arrow indicated by letter E indicates the contents of the abdominal cavity.
A 19-year-old man sustains a flexor tendon laceration while cutting an avocado. He presents to the emergency department and subsequently undergoes flexor tendon repair surgery. He is prescribed opioids for post-surgical pain management. Which one of the following has been shown to be a risk factor for prolonged opioid use?
A) Male gender
B) Tendon surgery
C) Trauma surgery
D) Younger age
The correct response is Option D.
In the realm of upper extremity surgery, younger age, bone procedures, mental health disorders, history of substance abuse, and pain disorders have consistently been found to be risk factors for prolonged opioid use. A specific gender has not been consistently shown to be a risk factor of opioid abuse following upper extremity surgery, with some studies pointing to female gender, while others point to male gender. Other factors that have been identified in specific studies include elective versus traumatic hand surgeries, lower versus higher income, and comprehensive insurance coverage versus medicare insurance. Aside from identifying risk factors, the majority of recent studies regarding prolonged opioid use after either upper extremity surgery or plastic surgery point to overprescription of opioids as a common problem. Recent reports demonstrate that narcotics are overprescribed by 40 to 60% after upper extremity surgery.
A 42-year-old woman undergoes wide local excision and sentinel node biopsy of an invasive melanoma of the forearm. After uneventful induction of general anesthesia, 1 mL of isosulfan blue dye is injected intradermally around the healing biopsy site on the forearm. The operation begins with excision of the axillary sentinel lymph node, which is identified high in the axilla. During removal of the sentinel node, blood pressure decreases to 60/40 mmHg. After discontinuing the procedure and administering a bolus of intravenous fluid, which of the following is the most appropriate next step?
A) Administer dexamethasone
B) Administer diphenhydramine
C) Administer lipid emulsion
D) Administer phenylephrine
The correct response is Option D.
Isosulfan blue has many uses. It is used to identify sentinel nodes in melanoma and Merkel cell skin cancer as well as in breast cancer. It is used in reverse axillary mapping in order to preserve extremity lymph nodes while harvesting those that drain the breast. Allergic reactions to this dye occur in up to 1.6% of patients.
These adverse events are unexpected and occur with unpredictable severity. There is no current validated method to detect or decrease the risk of allergic reaction. It is important for the plastic surgeon to be able to quickly recognize and treat complications. The most common allergic reactions are urticaria, blue hives, and skin rash. Anaphylaxis has been reported, but much less commonly.
In this scenario, the first sign of anaphylactic reaction is the sudden and severe drop in blood pressure. This can occur immediately or unexpectedly later during the surgical procedure. After halting the operation and starting a fluid bolus, a vasopressor should be administered to counteract the hypotension. Once this is done, both a corticosteroid (dexamethasone) and an antihistamine (diphenhydramine) should be given to counteract the allergic reaction. Changing the fraction of inspired oxygen will not help the allergic reaction. A needle thoracostomy would be indicated if dissection high in the axilla resulted in a tension pneumothorax, but that is not the case here. Administration of lipid emulsion is appropriate for local anesthetic toxicity.
A commonly suggested alternative to isosulfan blue, without the risk of anaphylaxis, is methylene blue. However, there is a significantly higher rate of wound healing complications with the use of methylene blue, which is why isosulfan blue is preferred in plastic surgical procedures, specifically skin grafting.
A 43-year-old woman is scheduled to undergo bilateral mastectomies and immediate tissue-expander–based reconstruction for breast cancer. To decrease the postoperative pain and requirement for narcotics, preoperative ultrasound-guided pectoral nerve (PECS) 1 and 2 regional blocks with liposomal bupivacaine are planned. The PECS 1 block is administered. Which of the following is the most appropriate location for infiltration of the local anesthetic when performing the PECS 2 block?
A) Between the breast parenchyma and pectoralis major
B) Between the pectoralis major and pectoralis minor
C) Between the pectoralis minor and the serratus anterior
D) Between the serratus anterior and the latissimus dorsi
The correct response is Option C.
The pectoral nerve (PECS) 1 and PECS 2 anesthetic blocks have become increasingly common methods for regional anesthesia to decrease postoperative pain in many early recovery after surgery (ERAS) protocols. The PECS blocks are thoracic regional fascial plane blocks that typically require ultrasound guidance for proper infiltration of the anesthetic between the muscles of the thoracic wall.
A PECS 1 block is performed between the pectoralis major and pectoralis minor muscles and anesthetizes the lateral and medial pectoral nerves. A PECS 2 block, in addition to the PECS 1 block, involves an additional injection of anesthetic between the pectoralis minor and serratus anterior muscles and blocks the intercostal and intercostobrachial nerves. The serratus plane block is another thoracic regional fascial plane block requiring injection of local anesthetic between the serratus anterior and latissimus dorsi muscles in order to block the long thoracic and thoracodorsal nerves.
A 165.3-lb (75-kg), 76-year-old woman is scheduled to undergo wide local excision of a large, invasive basal cell carcinoma of the cheek with flap reconstruction during general anesthesia. Medical history includes nonvalvular atrial fibrillation, hypertension, and an embolic stroke 3 months ago. Current medications include warfarin. Renal function is normal. Which of the following is the most appropriate preoperative anticoagulation management for this patient?
A) Discontinue warfarin 5 days prior to the procedure and initiate low-molecular-weight heparin bridging 3 days prior to the procedure
B) Discontinue warfarin 5 days prior to the procedure without bridging
C) Discontinue warfarin 7 days prior to the procedure and initiate low-molecular-weight-heparin bridging 3 days prior to the procedure
D) Immediately initiate low-molecular-weight heparin bridging and discontinue warfarin 5 days prior to the procedure
E) Do not discontinue warfarin
The correct response is Option A.
This patient has a very high thromboembolic risk and a high bleeding risk. Recommended heparin bridging is 3 days before a planned procedure (ie, two days after discontinuing warfarin), when the prothrombin time and international normalized ratio (PT/INR) has started to drop below the therapeutic range.
Atrial fibrillation accounts for the highest percentage of patients for whom perioperative anticoagulation questions arise. Importantly, patients with atrial fibrillation are a heterogeneous group; risk can be further classified according to clinical variables such as age, hypertension, congestive heart failure, diabetes, prior stroke, and other vascular disease.
Bridging anticoagulation may be appropriate in patients who will have a very high thromboembolic risk with prolonged interruption of their anticoagulant (generally a vitamin K antagonist). Individual patient comorbidities that increase bleeding risk may also need to be considered because an increased postoperative bleeding risk may be a reason to avoid bridging. Suggested use of bridging in individuals taking warfarin includes:
Embolic stroke or systemic embolic event within the previous three months
Mechanical mitral valve
Mechanical aortic valve and additional stroke risk factors
Atrial fibrillation and very high risk of stroke (eg, systemic embolism within the previous 12 weeks, concomitant rheumatic valvular heart disease with mitral stenosis)
Venous thromboembolism (VTE) within the previous three months (preoperative and postoperative bridging)
Recent coronary stenting (e.g. within the previous 12 weeks)
Previous thromboembolism during interruption of chronic anticoagulation
The other answer choices are not appropriate strategies for this patient.
An otherwise healthy 60-year-old woman underwent breast reconstruction with right free transverse rectus abdominis musculocutaneous (TRAM) flap 1 day ago. Cardiac monitoring shows no P waves and an irregular QRS complex. The patient is asymptomatic. Blood pressure is 120/80 mmHg and heart rate is between 130 and 139 bpm. Which of the following is the most appropriate first-line therapy for this patient?
A) Amiodarone
B) Digoxin
C) Diltiazem
D) Metoprolol
E) Propafenone
The correct response is Option D.
Atrial fibrillation manifests as irregularly irregular QRS complexes without P waves on ECG. Postoperative atrial fibrillation (POAF) is multifactorial in origin, and occurs in 5 to 10% of patients undergoing non-cardiothoracic surgery. In the largest trial to date comparing rate versus rhythm control (Atrial Fibrillation Follow-Up Investigation of Rhythm Management [AFFIRM]), rhythm control was associated with a greater number of hospitalizations, torsades de pointes, pulmonary events, gastrointestinal events, bradycardia, and QT prolongation events. Rate control is the treatment strategy of choice, with the goal of 80 to 100 bpm. Metoprolol is the preferred beta blocking agent due to its efficient conversion between IV and oral routes, low cost, and clinician familiarity. Diltiazem (non-dihydropyridine calcium channel blocker) is a second-line therapy, and is intended for use if first-line therapy is ineffective at rate control at maximum doses or the first-line therapy is contraindicated. Digoxin is considered when other options are ineffective or contraindicated because of its narrow therapeutic window. Amiodarone has both beta-blocking and calcium channel blocking properties in addition to its antiarrythmic effects. Amiodarone can be used in patients with decreased ejection fractions. It is associated with acute pulmonary toxicity.
A 63-year-old man undergoes ventral hernia repair with component separation. On the third postoperative day, his serum potassium level is 6.7 mEq/L. Vital signs are stable. Electrocardiography discloses sinus rhythm with flattened P waves and peaked T waves. Initial therapy should include the administration of which of the following drugs?
A) Albuterol
B) Calcium gluconate
C) Dextrose and insulin
D) Furosemide
E) Sodium bicarbonat
The correct response is Option B.
Intravenous calcium gluconate should be given to this patient with severe hyperkalemia and associated electrocardiographic changes.
Hyperkalemia causes a decrease in the resting membrane potential, leading to increased myocardial excitability and cardiac arrhythmias, including ventricular fibrillation and asystole. Electrocardiographic changes associated with progressive hyperkalemia include peaked T waves, prolonged P-R segment, flattening/loss of P waves, widening of QRS complex, ectopic beats, ventricular fibrillation, conduction blocks, and asystole.
Neither a specific serum potassium level threshold nor an electrocardiographic pattern that predisposes patients to life-threatening cardiac arrhythmias has been well established. However, the initial therapy for patients presenting with a serum potassium level greater than 6 mEq/L and hyperkalemia-related electrocardiographic changes should focus on stabilizing the myocardium to prevent or reverse cardiac arrhythmias by intravenous administration of a calcium salt (gluconate or chloride). The onset of action is nearly immediate, but the duration of the protective effect is only 30 to 60 minutes. Therefore, repeat administration may be required.
Interventions to shift potassium intracellularly (intravenous dextrose and insulin, with or without nebulized albuterol/beta-2 agonist; intravenous sodium bicarbonate) or eliminate it from the body (intravenous furosemide, rectal or oral potassium-binding agents, hemodialysis) should be carried out as soon as possible after intravenous administration of calcium.
A 65-year-old man presents to the office for panniculectomy evaluation. Medical history includes anxiety, controlled hypertension, hyperlipidemia, and borderline diabetes that is controlled by diet only. Current medications include lisinopril, carvedilol, atorvastatin, zolpidem, and sertraline. After consultation, the surgeon determines the patient is a good candidate for panniculectomy. It is most appropriate for the patient to stop taking which of the following medications the night before surgery?
A) Atorvastatin
B) Carvedilol
C) Lisinopril
D) Sertraline
E) Zolpidem
The correct response is Option C.
All the medications listed are safe for use the night before surgery with the exception of an ACE inhibitor. While there have been some questions in the past regarding the safety of selective serotonin reuptake inhibitors (SSRIs) like sertraline due to bleeding concern, the current consensus is that it is safe to take.1 Beta blockers can have a beneficial effect for the cardiovascular system before surgery and thus, patients may take them even the morning of surgery.2 Lisinopril, however, can lead to hypotension during surgery and anesthetic management, and should be stopped the night before surgery. As an ACE inhibitor, it may counter the medications the anesthesiologist uses for blood pressure control.
A 38-year-old woman is undergoing a routine abdominoplasty at an outpatient surgery center under general anesthesia. Thirty minutes into the operation, the anesthesiologist reports high end-tidal CO2 production and tachycardia. Which of the following is the most appropriate first step in management?
A) Administer dantrolene
B) Discontinue volatile anesthetic agents
C) Infusion of lipid emulsion
D) Switch to total intravenous anesthesia
E) Treatment of arrhythmia
The correct response is Option B.
Malignant hyperthermia is an anesthetic crisis that is potentially fatal if not appropriately managed. The mechanism of malignant hyperthermia is an accelerated release of calcium from the sarcoplasmic reticulum. The increasing release of calcium surpasses uptake and leads to an inability to control the intracellular calcium level. The symptoms of malignant hyperthermia include unexplained high end-tidal CO2 levels, tachycardia, increasing body temperature, masseter muscle rigidity, and skeletal muscle rigidity. The first step in the management of malignant hyperthermia is discontinuing the volatile anesthesia. The subsequent steps in management include administering dantrolene, switching to IV anesthesia, and treatment of arrhythmia. Depolarizing muscle relaxants can cause malignant hyperthermia and these drugs should be immediately discontinued and not administered. Infusion of lipid emulsion is done for lidocaine toxicity.
A 67-year-old woman is scheduled to undergo carpal tunnel release under monitored anesthesia care with local anesthetic. Her comorbidities include type 1 diabetes mellitus (recent hemoglobin A1c is 7.4%), current everyday smoking, and rheumatoid arthritis, for which she takes methotrexate. Which of the following is the most appropriate antibiotic therapy to reduce this patient’s risk for surgical site infection?
A) Intravenous cefazolin, 30 minutes prior to induction, cephalexin 500 mg four times a day for 7 days postoperatively
B) Intravenous cefazolin, 30 minutes prior to induction, with no postoperative therapy
C) Intravenous cefazolin, 60 minutes prior to induction, cephalexin 500 mg four times a day for 7 days postoperatively
D) Intravenous cefazolin, 60 minutes prior to induction, with no postoperative therapy
E) No antibiotics indicated
The correct response is Option E.
Several studies have shown that timing of antibiotic delivery does impact the rate of surgical site infection (SSI). Current recommendations suggest that, when indicated, antibiotics should be given between 1 and 2 hours before surgery. There are no data to support a reduction in SSI risk when antibiotics are given within 30 minutes of surgery.
In the retrospective review by Bykowski et al, authors reported the SSI rates in patients undergoing elective soft-tissue surgery. Rates of SSI did not differ between patients who received preoperative antibiotics and those who did not (0.54% versus 0.26%, p less than 0.05). When a subgroup analysis was performed, SSI infection rates for patients who were active smokers, diabetics, and with procedure length greater than 60 minutes showed no difference with or without antibiotic administration.
Traditionally, patients with rheumatoid arthritis are viewed to be at higher risk for infection following surgery. There are no data to suggest that there is a risk reduction with the use of preoperative and/or postoperative antibiotics. Also, methotrexate does not increase one’s SSI risk and is therefore not an indication for perioperative antibiotic therapy.
An otherwise healthy 35-year-old woman is scheduled to undergo routine full abdominoplasty while receiving conscious sedation and local anesthesia. Which of the following intravenous sedation regimens is most likely to reduce this patient’s pain and anxiety while minimizing the risk for respiratory depression?
A) Fentanyl alone
B) Ketamine and fentanyl
C) Midazolam alone
D) Midazolam and fentanyl
E) Midazolam and propofol
The correct response is Option D.
The advantage of using this combination is that midazolam has excellent anxiolytic and amnestic effects, whereas fentanyl is an excellent short-acting analgesic. A recent multicenter, randomized study demonstrated that the combination of fentanyl and midazolam is superior to midazolam alone in decreasing the patient’s subjective report of pain and anxiety.
The main drawback of fentanyl is respiratory depression; however, it does have a very short half-life. Midazolam, in contrast, has minimal effects on the respiratory system except in some older patients, in whom lower doses must be used. Continuous oxygen saturation monitoring and checking the patient’s respiratory status and other vital signs every 5 minutes are important for patient safety. Medications are only administered in small doses at each 5-minute interval (no more than 50 mg of fentanyl and 2 mg of midazolam at a time). This helps achieve a steady-state effect. Both of these medications have antagonists that are able to reverse their effects. Flumazenil and naloxone, the antagonists of midazolam and fentanyl, respectively, should be readily available in the operating room. The surgeon should be familiar with their dosage and administration.
Ketamine would not resolve anxiety in this patient.
Use of propofol in combination with an opiate and benzodiazepine can be used for conscious sedation; however, the disadvantage of this combination is the higher risk of respiratory depression and the lack of a reversing agent for propofol. Because a deeper level of sedation can be maintained, this technique is preferable for selected patients who are very anxious. A recently published series of abdominoplasty with sedation using propofol used monitored anesthesia care by an anesthesiologist or nurse anesthetist.
Propofol and benzodiazepines have no significant analgesic effect.
A 26-year-old man is scheduled to undergo septorhinoplasty following a nasal bone fracture 3 years ago. He has mild von Willebrand disease. The day of the operation, the surgeon administers 0.3 ?g/kg of 1-deamino-8-D-arginine-vasopressin before and after the surgery to help decrease postoperative bleeding. Which of the following is the initial mechanism by which the administered medication facilitates hemostasis in this patient?
A) Activating the Factor V Leiden molecule in the clotting cascade
B) Cleaving the fibrinogen molecule to fibrin
C) Inducing the release of von Willebrand factor from its storage sites in endothelial cells
D) Irreversibly blocks the formation of thromboxane A2 in platelets
E) Supporting complex formation with tissue factor, thereby providing enough thrombin to form fibrin plugs to stop minor bleeds
The correct response is Option C.
This patient is suffering from a bleeding disorder called von Willebrand disease (VWD), which occurs when the von Willebrand factor (VWF) is deficient or qualitatively abnormal.
Von Willebrand factor (VWF) works by mediating the adherence of platelets to one another and to sites of vascular damage. It also binds to Factor VIII, keeping it inactive while in circulation since Factor VIII rapidly degrades when not bound to VWF.
VWD is the most common of the inherited bleeding disorders, with an estimated prevalence in the general population of 1 percent by laboratory testing. Patients will often present with signs of easy bruising, extensive bleeding after dental work, heavy or long menstrual periods, and prolonged nose bleeds. Patients with a history of abnormal bleeding should always be properly worked up prior to surgery. There has been an extensive discussion over the years about the treatment of patients suffering from von Willebrand’s disease and rhinoplasty procedure.
The recommended treatment of patients suffering from VWD undergoing rhinoplasty procedure is 0.3 ?g/kg of 1-deamino-8-D-arginine-vasopressin (Desmopressin). Desmopressin is an analogue of vasopressin that exerts a substantial hemostatic effect, by inducing the release of von Willebrand factor from its storage sites in endothelial cells. Patients with the mild form of VWD have lower than normal levels of VWF, and the release of the additional proteins from the endothelial cells aids with clotting.
Factor V Leiden is a mutated form of human Factor V, which condition that result in a hypercoagulable state. Due to this mutation, Protein C, an anticoagulant protein which normally inhibits the pro-clotting activity of factor V, is not able to bind normally to Factor V, leading to a hypercoagulable state. Desmopressin does not have a direct interaction on this molecule.
Thrombin is an enzyme that converts fibrinogen to fibrin, and a reaction that leads to the formation of a fibrin clot. There are several thrombin products commercially available.
Hemophilia is a condition that is deficient in Factor VII. Recombinant activated factor VII.
Aspirin irreversibly blocks the formation of thromboxane A2 in platelets, producing an inhibitory effect on platelet aggregation.
A 71-year-old man with chronic obstructive pulmonary disease (COPD) is transferred to the hospital with multiple facial lacerations and fractures following a fall. He has increasing confusion on arrival at the hospital. His wife mentions that he had bled a significant amount after the fall. Laboratory studies show:
On the basis of these findings, this patient’s primary metabolic disorder is which of the following?
A) Metabolic acidosis due to exacerbation of his COPD
B) Metabolic acidosis due to hemodilution from bleeding
C) Metabolic alkalosis due to exacerbation of his COPD
D) Metabolic alkalosis due to hemodilution from bleeding
The correct response is Option A.
The pH is low, indicating an acidosis, while the bicarbonate is high, indicating that a respiratory acidosis with metabolic compensation is present. The pH is low so the primary problem is an acidosis and is likely to be respiratory in nature. The PaCO2 is very high and indicates a respiratory acidosis is present. The very high PaCO2 level seen here is typical of a person with respiratory disease that results in retention of CO2, (ie, the primary clinical problem is respiratory failure due to chronic obstructive pulmonary disease).The most likely cause for this acid-base abnormality is an acute exacerbation of chronic obstructive pulmonary disease.
A 69-year-old woman presents to the emergency department because she has had increasing redness and pain in her left reconstructed breast for the past 24 hours. Blood pressure is 80/40 mmHg, heart rate is 130 bpm, and respiratory rate is 32/min. Initial plasma lactate level is 5.2 mmol/L. Ultrasonography shows no fluid collections within the breast. Intravenous fluid resuscitation is started. Administration of intravenous antibiotics is most appropriate within how many hours?
A) 1
B) 3
C) 6
D) 12
E) 24
The correct response is Option A.
The 2016 Surviving Sepsis Campaign guidelines strongly recommend that administration of intravenous antibiotics be initiated as soon as possible after recognition and within 1 hour for both sepsis and septic shock.
In the presence of sepsis or septic shock, increasing delays in administration of appropriate antibiotics are associated with increasing mortality and detrimental effects on secondary endpoints, such as length of hospital stay, acute kidney injury, acute lung injury, and the Sepsis-Related Organ Assessment score.
Although data suggest that optimal outcomes are achieved by the earliest possible administration of appropriate antibiotics following recognition of sepsis, 1 hour was recommended as a reasonable minimal target, considering multiple patient and organizational factors that may cause delay.
A 65-year-old woman undergoes ventral hernia repair with component separation and mesh placement. On postoperative day two, the patient suddenly becomes unresponsive and has no palpable pulse. Cardiopulmonary resuscitation (CPR) is promptly started and a cardiac monitor is attached. Cardiac tracing is consistent with pulseless electrical activity (PEA). Administration of which of the following drugs is most appropriate in this patient?
A) Adenosine
B) Atropine
C) Diltiazem
D) Dopamine
E) Epinephrine
The correct response is Option E.
Epinephrine is the initial drug of choice in the acute management of this patient with pulseless electrical activity (PEA).
Desirable effects of epinephrine in the treatment of cardiac arrest include vasoconstriction (alpha-1 adrenergic) and increase in cardiac output (beta-1 adrenergic). According to current Advanced Cardiac Life Support guidelines, epinephrine should be administered to a patient in cardiac arrest as soon as the electrocardiographic diagnosis of either PEA or asystole is made. The intravenous dose is 1 mg every 3 to 5 minutes, always followed by a 20 mL normal saline flush. Cardiopulmonary resuscitation should not be halted for drug administration. The drug can also be administered via intraosseous access or through the endotracheal tube.
The other drugs listed are not indicated in the initial treatment of PEA.
A 25-year-old man presents for consultation for surgical resection of a large abdominal pannus. The patient’s mother has a history of malignant hyperthermia. Which of the following best describes the inheritance pattern of this condition?
A) Autosomal dominant
B) Autosomal recessive
C) Mitochondrial
D) X-linked dominant
E) X-linked recessive
The correct response is Option A.
Malignant hyperthermia is an autosomal dominant trait, thus, based on Mendelian Genetics, if one parent has a confirmed diagnosis, their biological children will have a 50% chance of inheritance of the affected gene.
Malignant hyperthermia is a potentially life-threatening condition. Individuals with this inherited myopathy present with a hypermetabolic reaction to potent volatile anesthetic gases, such as halothane, enflurane, isoflurane, sevoflurane, and desflurane. Individuals are also susceptible to the depolarizing muscle relaxant succinylcholine. The preoperative workup for an individual with suspected malignant hyperthermia is the Caffeine-Halothane Contracture Test. In this test, a piece of skeletal muscle is excised, and its contractile properties are determined when exposed to the ryanodine receptor agonist halothane and/or caffeine. Abnormal contractile activity is indicative of susceptibility. Based on basic Mendelian Genetics, the risk of inheritance is 50%.
Given this pattern of inheritance, x-linked, autosomal recessive and mitochondrial inheritance are incorrect answers.
A 45-year-old man presents with significant closed head injury. Maintenance fluids are initiated because of progressive nausea with reduced oral intake. CT scan of the head shows diffuse cerebral edema. Administration of which of the following solutions is most appropriate in this patient?
A) Dextrose 5% in water
B) Hypertonic (3%) saline
C) Hypotonic (0.45%) saline
D) Physiologic (0.9%) saline
E) Ringer’s lactate
The correct response is Option B.
The patient is showing signs of symptomatic progressive intracranial pressure following head trauma. Hypertonic infusion therapy can be used in this scenario to decrease intracranial pressure and curtail progressive cerebral edema. Hypertonic (3%) saline fits into conventional algorithms for treatment of symptomatic acute intracranial hypertension along with hyperventilation, mannitol, diuretics, and surgical decompression. Hypertonic solutions have been shown to decrease intracranial pressure with greater efficiency than mannitol in early stages of trauma for patients with evolving brain injury.
Ringer’s lactate and physiologic (0.9%) saline solution would not prevent or counteract progressive cerebral edema following head trauma. Hypotonic solutions (such as dextrose 5% in water and 0.45% saline solutions) are broadly contraindicated in patients who suffer severe traumatic brain injury, because they may lower serum osmolarity and exacerbate cerebral edema.
A 9-month-old female infant with severe metopic craniosynostosis requires bifrontal craniotomy and a fronto-orbital advancement. The anesthesiologist is concerned about intraoperative blood loss and the need for blood transfusion. Which of the following drugs administered by intravenous infusion at the time of cranial reconstruction is most likely to reduce both intraoperative and postoperative bleeding?
A) Aprotinin
B) Erythropoietin
C) Fibrinogen
D) Protamine
E) Tranexamic acid
The correct response is Option E.
Acute blood loss and the need for autologous blood transfusions are common in infants undergoing craniofacial procedures. Techniques to limit blood loss and transfusions have been studied extensively in craniosynostosis surgery. Tranexamic acid (TXA) is a synthetic analog of the amino acid lysine, which inhibits the conversion of plasminogen to plasmin when intravenously administered. TXA inhibits the proteolytic action of plasmin, thus inhibiting fibrinolysis. It has been shown in multiple studies to reduce both intraoperative and postoperative blood loss.
Aprotinin is a small protein bovine pancreatic trypsin inhibitor with anti-thrombolytic potential. It was taken off the market in the United States in 2007 as its use was associated with increased complications and death. It has since been reapproved in Canada and Europe but remains banned in the United States. Protamine is a drug used to reduce the effects of heparin toxicity and of no benefit in this clinical scenario. Erythropoietin is a recombinant glycoprotein cytokine that stimulates red cell production. When given preoperatively, it has been shown to reduce the need for blood transfusion (not necessarily acute blood loss) in craniosynostosis surgery. Fibrinogen is not administered intravenously. Fibrin glue does reduce blood loss in craniosynostosis procedures, but it is administered topically, not intravenously.
A 48-year-old man who sustained severe traumatic brain injury and extensive facial fractures in a motor vehicle collision 2 weeks ago is receiving ventilatory support and enteral nutrition via feeding tube. An indirect calorimetry assessment shows a respiratory quotient (RQ) value of 1.3. This value is most closely associated with which of the following types of metabolism?
A) Carbohydrate oxidation
B) Ketosis
C) Lipid oxidation
D) Lipogenesis
E) Protein oxidation
The correct response is Option D.
Indirect calorimetry measurements, or a metabolic cart, are used to help calculate the resting energy expenditure (REE) and respiratory quotient (RQ) as a means to help determine the caloric needs of a patient as well as optimize the patient’s nutrition. Indirect calorimetry measures the amount of oxygen consumed (VO2) and the amount of carbon dioxide produced (VCO2) by the patient. REE is calculated by the Weir equation [REE = (3.94 x VO2) + (1.1 x VCO2)] while the RQ is calculated as VCO2 / VO2. The calculated values of the respiratory quotient are reflections of what fuels are being oxidized by the patient with typical values as follows:
Optimal values of RQ for nutrition assessment are between 0.8 and 0.9, representing a balance between lipid and glucose oxidation. Values below 0.8 suggest underfeeding, while values greater than 1.0 suggest overfeeding. A value of 1.3 in this patient suggests significant overfeeding and lipogenesis and the enteral nutrition should be adjusted based on the current energy expenditure obtained from indirect calorimetry.
Ketosis is not measured by RQ.
A 54-year-old woman undergoes abdominoplasty and hysterectomy. Postoperative rivaroxaban is initiated for prevention of deep venous thrombosis. Three days later, she presents for follow-up, and a hematoma requiring drainage is noted. This outcome is most likely related to the fact that rivaroxaban blocks the coagulation cascade in which of the following ways?
A) Binds factors II, VII, IX, and X
B) Prevents conversion of prothrombin to thrombin
C) Prevents degranulation of platelets
D) Prevents thrombin from activating fibrinogen
E) Prevents tissue factor:factor VIIa complex formation
The correct response is Option B.
The direct anticoagulation agent rivaroxaban (Xarelto) is a direct anticoagulant, which acts within the clotting cascade by blocking Factor Xa, which, along with Factor Va, helps convert prothrombin to thrombin. This step in the cascade is where the intrinsic and extrinsic pathways intersect and the common pathway that leads to fibrinogen being cleaved to fibrin and stabilized by factor XIIIa as a cross-linked clot.
Aspirin is a drug that interferes with platelet function. Coumadin affects the vitamin K dependent factors II (prothombin), VII, IX and X. Heparin prevents clot propagation by blocking thrombin-mediated activation of fibrinogen to fibrin. The primary benefits of the direct anticoagulation agents over coumadin include no need for monitoring and equivalence in efficacy across many clinical situations. It is excreted by the kidney, so dosages must be altered or the drug avoided in renal failure. A U.S. Food & Drug Administration–approved reversal agent, recombinant coagulation factor Xa (Andexxa), is now available on the market for life-threatening or uncontrolled bleeding in patients using direct anticoagulants affecting factor Xa, like rivaroxaban. Prior to this, administration of fresh frozen plasma (FFP) was the antidote of choice.
A 45-year-old woman with breast cancer is scheduled to undergo bilateral mastectomy. Immediate breast reconstruction with deep inferior epigastric perforator (DIEP) flaps is planned. Which of the following factors is most likely to increase this patient’s risk for microsurgical thrombotic complications?
A) BRCA-2 genetic mutation
B) Caprini Risk Assessment Model score of 5
C) History of prior irradiation following lumpectomy
D) History of prior thrombotic event
E) Sickle cell trait
The correct response is Option D.
Virchow recognized a triad of factors that predispose to intravascular thrombosis. These are stasis in blood flow, endothelial (intimal) damage, and intrinsic hypercoagulability. One recent review identifies a personal history of prior thrombotic event as perhaps the single greatest risk factor of a hypercoagulable state. Other known hypercoagulable disorders that can be identified by specific blood test include Factor V Leiden mutation, prothrombin gene (20210A) mutation, protein C deficiency, protein S deficiency, antithrombin III (AT3) deficiency, lupus anticoagulant, anticardiolipin antibodies, and anti-beta-2 glycoprotein 1 antibodies. These appear to increase the risk of microsurgical thrombotic complications as well. However, the severity of the increased risk for each remains to be fully elucidated. Another published series of 41 patients showed an 80% free flap success rate in patients with identified hypercoagulable states. Therefore, a thorough preoperative evaluation of patients for microvascular procedures may help to identify those at increased risk for thrombotic complications, guiding patient selection and perioperative anticoagulation therapy.
The Caprini Risk Assessment Model (RAM) is used to assess venous thromboembolism (VTE) risk, and its use has been validated in plastic and reconstructive surgery patients. The Caprini RAM score for the patient in this question is 5 (2 risk factor points for major surgery over 45 minutes, 2 points for presence of malignancy, and 1 point for ages 41 to 60). According to the recommendations of the American Society of Plastic Surgeons VTE Task Force Report, one should consider postoperative chemoprophylaxis for VTE for this patient who is at intermediate risk. However, data are lacking, which would support the use of the Caprini Risk Assessment Model as a tool to stratify risk of microvascular thrombotic complications.
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BRCA-2 genetic mutation is a heritable condition that significantly increases lifetime risk for breast and ovarian cancer. However, it has not been shown to play any role in risk for thrombotic events.
Similarly, sickle cell trait (heterozygous carrier of the sickle cell mutation in the hemoglobin-beta gene) has not been shown to increase risk for microsurgical thrombotic complications.
While chest wall irradiation might negatively impact the recipient chest wall vessels for deep inferior epigastric perforator (DIEP) flaps, the impact of radiation following a lumpectomy is very unlikely to be as significant as that of a prior personal thrombotic event.
A 30-year-old woman, gravida 1, para 0, who is at 36 weeks’ gestation presents to the emergency department after sustaining blunt trauma injury in a motor vehicle collision. Physical examination shows a visible seat belt sign, but she is hemodynamically stable. Secondary assessment is unremarkable. Which of the following is the most appropriate next step?
A) Determine maternal Rh status
B) Discharge with obstetric follow-up
C) Initiate scalp monitoring of the fetus
D) Perform diagnostic peritoneal lavage
E) Perform MRI of the abdomen/pelvis
The correct response is Option A.
Traumatic placental injury can cause maternal-fetal hemorrhage in 10 to 30% of pregnant trauma patients. The majority of these are subclinical, without measurable effects to the fetus. However, as little as 0.001 milliliter of Rh-positive fetal blood can cause alloimmunization of an Rh-negative mother. Therefore, determination of Rh status is mandatory for all pregnant trauma patients and all Rh-negative of these should be given anti-D immune globulin (IgG). A single dose administered within 72 hours from injury may provide protection against sensitization in up to 90% of the cases. Higher doses may be necessary if it is determined that transplacental hemorrhage was in excess of 30 milliliters.
Simply discharging the patient for a future obstetric follow up is not acceptable. At least 4 hours of electronic fetal monitoring should be provided to all pregnant trauma patients with >= 23 weeks gestation.
Internal electronic fetal heart rate monitoring (with an electrode in the scalp) is not indicated at this time. Instead, external monitoring could be done using a dedicated Doppler ultrasound device.
MRI of the abdomen/pelvis and diagnostic peritoneal lavage are not indicated in the scenario described. Radiographic imaging generally indicated for trauma evaluation, including abdominal computed tomography, should not be deferred or delayed due to concerns of fetal exposure to radiation. Ultrasonography (FAST) should be part of the secondary survey in all pregnant trauma patients.
A 69-year-old man is scheduled to undergo excision and direct closure of a basal cell carcinoma of the chest. Medical history includes aspirin 81 mg daily for primary prevention of cardiovascular disease. Compared with patients not taking aspirin prophylaxis, this patient is most likely at risk for which of the following complications?
A) Hematoma
B) Worse cosmetic outcome
C) Wound dehiscence
D) Wound infection
E) None of the above
The correct response is Option E.
Systematic review drawing from 30 studies and more than 14,000 patients undergoing minor cutaneous surgery firmly supports continuation of aspirin therapy in all minor cutaneous surgery, as patients on aspirin monotherapy are at no greater risk of hemorrhagic complications than those on no agents. While a case-by-case risk profiling in all patients on aspirin therapy is prudent, the preponderance of evidence favors meticulous hemostasis over aspirin cessation in prevention of bleeding complications in minor cutaneous surgery.
There is no reported association between aspirin utilization and increased risk of wound dehiscence, wound infection, or cosmetic outcome.
An otherwise healthy 35-year-old woman, gravida 3, para 3, presents for abdominoplasty. When combined with non-opioid analgesics and/or NSAIDs, which of the following is the most appropriate pain management for this patient?
A) Administration of epidural anesthetic
B) Infiltration of wound with liposomal bupivacaine
C) Intraoperative dexamethasone administration
D) Intraoperative ketamine infusion
E) Intraoperative lidocaine infusion
The correct response is Option B.
Enhanced recovery after surgery (ERAS) protocols are multimodal, multidisciplinary perioperative care pathways designed to achieve rapid recovery after surgery. These pathways include consensus recommendation for postoperative analgesia. In addition, improved postoperative pain control can be obtained with emphasis on the use of procedure-specific pain management. Some procedures have a higher propensity for persistent postoperative pain which generally are neuropathic in origin, ie: mastectomy, thoracotomy, hernia repair, abdominal wall surgeries. The primary goal of an optimal pain therapy is to provide “dynamic” pain relief (pain relief during movement) that would allow early ambulation while reducing opioid consumption. The ideal multimodal analgesic technique would include a local/regional analgesic (wound infiltration or peripheral nerve block) as the principal component because they provide excellent dynamic pain relief. Liposomal bupivacaine (Exparel) allows delivery of bupivacaine for 96 hours with a single local administration. There can be significant pain relief with the combination of wound infiltration with liposomal bupivacaine acetaminophen and NSAIDs or COX2 inhibitors as multimodal analgesic regimens. Epidural analgesia, dexamethasone, lidocaine and ketamine infusions all have demonstrated postoperative pain relief and reduction in opioid requirements to varying degrees. But local/regional analgesia (wound infiltration) should be used as the first-line analgesic therapy, which should be combined with acetaminophen, NSAIDs or COX1 inhibitors.
A 25-year-old man is being considered as an organ donor after sustaining traumatic brain injury in a motorcycle crash. Which of the following findings is most likely to confirm brain death?
A) Absence of deep tendon reflexes
B) Mild cough with tracheal tube manipulation
C) 1 mm pupillary constriction when tested for pupillary reflex
D) No movement of lid or eyes when touching cornea
E) Nystagmus with caloric testing
The correct response is Option D.
Brain death is a criterion for nonliving organ donation. Absence of all brain stem reflexes needs to be present for brain death to occur. Absence of corneal reflex demonstrates an absence of brain stem reflexes. Presence of pupillary reflex and nystagmus during caloric test demonstrates a positive finding and presence of brain stem reflex. Mild cough or gag during tracheal manipulation demonstrates presence of brain stem reflex. Any respiratory rate during apnea test is seen as a sign of brain stem function. Evaluation of deep tendon reflexes is not part of assessing brain death.
A 30-year-old woman with a history of Crohn disease undergoes ventral hernia repair. BMI is 31 kg/m2. Which of the following is the greatest risk factor for postoperative nausea and vomiting in this patient?
A) Elevated body mass index
B) Perioperative fasting
C) Placement of nasogastric tube
D) Supplemental oxygen
E) Young age
The correct response is Option E.
Postoperative nausea and vomiting remains a significant problem after cosmetic and reconstructive plastic surgery. Reported studies on the condition list incidences as high as 56%, whereas a meta-analysis found that the overall incidence was 28.3%.
For many plastic surgery procedures, general inhalational anesthesia and narcotic pain control are required and may predispose patients to postoperative nausea and vomiting (PONV).The effects can be disastrous including hematoma, incisional dehiscence, respiratory compromise, pain, longer hospital stay, slower recuperation, and patient dissatisfaction.
A number of risk factors have been associated with a positive overall incidence of PONV. Patient-specific risk factors for PONV in adults include female sex, a history of PONV, non-smoking status, young age, general versus regional anesthesia, postoperative opioids, and type of surgery.
Other factors have been disproven including placement of a nasogastric tube, peri-operative fasting, obesity, and supplemental oxygen.
A 37-year-old woman is scheduled to undergo skin-sparing mastectomy of the left breast with immediate deep inferior epigastric perforator (DIEP) flap reconstruction. Which of the following interventions is most likely to decrease this patient’s postoperative narcotic needs?
A) Application of a preoperative compression garment
B) Hypnosis
C) Ondansetron therapy
D) Oxycodone therapy
E) Pregabalin therapy
The correct response is Option E.
Pregabalin (Lyrica) has been shown to decrease narcotic needs after breast surgery. It is a gamma-aminobutyric acid (GABA) analogue and decreases GABA in the brain and acts primarily as an anticonvulsant. It is more potent than gabapentin as an analgesic.
Compression garments would be useful for post-mastectomy lymphedema but would not decrease narcotic needs. Hypnosis might decrease narcotic use slightly, but the effects are negligible. Oxycodone is a narcotic which does not decrease narcotic needs. The use of ondansetron (Zofran) has not been shown to reduce post-operative narcotic requirements.
After an uneventful breast reconstruction with an abdominal flap, a healthy 45-year-old woman is started on ketorolac as part of her multi-modality pain control regimen. Inhibition of which of the following is the primary mechanism of action for the increased bleeding time associated with this drug?
A) Lipoxygenase
B) Nitric oxide
C) Prostacyclin
D) Prostaglandins
E) Thromboxane A2
The correct response is Option E.
The primary mechanism of action for the increased bleeding time associated with the use of ketorolac is the inhibition of thromboxane A2. Ketorolac is a non-steroidal anti-inflammatory drug (NSAID). Most NSAIDs inhibit the activity of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), and thereby the synthesis of thromboxane A2. This produces a systemic bleeding tendency by impairing thromboxane-dependent platelet aggregation and consequently prolonging the bleeding time. It is thought that inhibition of COX-2 leads to the anti-inflammatory, analgesic, and antipyretic effects through the inhibition of formation of prostaglandins and prostacyclin. Inhibition of lipoxygenase and nitric oxide are not the primary mechanisms associated with NSAID-related platelet inhibition.
A 10-year-old boy undergoes surgical repair of microtia of the right ear. During cartilage rib harvest, the right thorax is damaged with visualization of the lung. After repair of the pleura, Valsalva maneuver is performed with no evidence of an air leak. An intraoperative chest x-ray is negative for pneumothorax. Several minutes later in the PACU, the patient becomes hypotensive and tachypneic, and his oxygen saturation decreases to the mid-80s, despite use of a non-rebreather mask. Which of the following is the most appropriate next step in management?
A) Draw arterial blood gas
B) Intubation
C) Needle decompression of the right chest
D) Open the chest incision
E) Portable chest x-ray study
The correct response is Option C.
The patient shows all the signs of tension pneumothorax, and although the precise etiology is unclear, the patient requires decompression. Intubation will not help relieve the tension and pressure, with decreased venous return jeopardizing hemodynamic stability.
Immediate chest x-ray is inappropriate because of the time required.
Opening the chest incision is not a good option because it requires surgical equipment, general anesthesia, and cannot be completed in a timely fashion.
Needle decompression at the second intercostal is the standard of care to decompress a tension pneumothorax. After oxygen saturation and hemodynamics are stabilized, definitive treatment of pneumothorax can be pursued. This would include placement of chest tube to low suction and serial chest x-ray to monitor the progress of the lung inflation.
Arterial blood gas will not help make the diagnosis and potentially will delay the appropriate intervention.
A 36-year-old health-care worker sustains a needle-stick injury from a hepatitis C–seropositive patient. Immediate testing for anti-HCV antibodies and confirmatory immunoassays for HCV-RNA are performed. Initial follow-up testing after exposure should be performed at which of the following time periods?
A) 1 week
B) 3 weeks
C) 6 weeks
D) 12 weeks
E) 24 weeks
The correct response is Option C.
It is recommended that follow-up retesting be done at 6 weeks, 3 months, and 6 months in known HCV exposure cases. Tests at 1 or 3 weeks would possibly lead to false negative results. There is no advantage in waiting beyond 6 weeks.
A 70-year-old man is in the recovery room after undergoing radial forearm free flap reconstruction for squamous cell carcinoma of the tongue. He has a 30-pack year history of smoking. The patient is ventilated with a tracheostomy tube. Two days postoperatively, sedation is turned off for an hour with the goal of weaning the patient off mechanical ventilation. He becomes agitated and delirious. Which of the following drugs should be avoided in this patient during the postoperative period?
A) Albuterol
B) Diphenhydramine
C) Neostigmine
D) Propranolol
E) Varenicline
The correct response is Option B.
Postoperative delirium is an acute brain dysfunction that is characterized by changes in levels of consciousness, inattention, and disorganized thinking. There are two types of delirium. Delirium can manifest with hyperactive signs (agitation, restlessness), or hypoactive signs (lethargy, inattentiveness). It is very common in hospitalized patients, with 60 to 80% of mechanically ventilated patients and 20 to 50% of patients with a lower severity of illness developing delirium at some point during their hospitalization.
For patients at risk of postoperative delirium, benzodiazepines and antihistamines should be avoided, as these medications could exacerbate the symptoms.
A 75-year-old woman with type 1 diabetes mellitus undergoes closure of a sternotomy wound using pectoralis major muscle flaps. On postoperative day 2, her plasma creatinine level has increased to 2.2 from 1.1 mg/dL preoperatively. The patient is hemodynamically stable in the ICU, and her central venous pressure is within normal range. An intravenous infusion of normal saline is initiated. Which of the following is the most appropriate next step in management?
A) Administration of a diuretic B) Discontinuation of enteral nutrition and initiation of parenteral nutrition C) Discontinuation of protein intake D) Infusion of low-dose (<2.5 ?g/kg/min) dopamine intravenously E) Plasma glucose control protocol
The correct response is Option E.
This patient has acute kidney injury (AKI) after a surgical procedure. International practice guidelines recommend insulin therapy for targeted glucose control in critically ill patients. Although the Kidney Disease – Improving Global Outcomes (KDIGO) task force recommended a plasma glucose target of 110 to 149 mg/dL, the latest recommendation by the Surviving Sepsis Campaign is for an upper blood glucose level not higher than 180 mg/dL.
Other recommendations for prevention and treatment of AKI by the 2012 KDIGO Clinical Practice Guideline included: Isotonic crystalloids rather than colloids (albumin or starches) as initial management for expansion of intravascular volume in patients at risk for or with AKI; Avoding restriction of protein intake with the aim of preventing or delaying initiation of renal replacement therapy (RRT); Administration of 0.8 to 1.0 g/kg/d of protein in non-catabolic AKI patients without need for dialysis; 1.0 to 1.5 g/kg/d in patients with AKI on RRT; and up to a maximum of 1.7 g/kg/d in patients on continuous renal replacement therapy (CRRT) and in hypercatabolic patients; Providing nutrition preferentially via the enteral route in patients with AKI; Not using diuretics to prevent AKI; Not using diuretics to treat AKI, except in the management of volume overload; Not using low-dose dopamine to prevent or treat AKI
A 67-year-old man undergoes ventral hernia repair and abdominal wall reconstruction with component separation. On postoperative day 5, the patient develops a cough; temperature is 39.0°C (102.2°F). Chest x-ray study shows right middle lobe pneumonia. Antibiotic therapy is promptly initiated. Despite adequate fluid resuscitation, the patient becomes hypotensive (mean arterial pressure < 65 mmHg). Which of the following blood tests is most appropriate to establish the suspected diagnosis of septic shock?
A) Albumin
B) C-reactive protein
C) Lactate
D) Plasminogen
E) White blood cell count
The correct response is Option C.
Obtaining a serum lactate level is the most appropriate next step for the diagnosis of septic shock in this scenario. Patients with septic shock can be clinically identified by having both of two criteria:
Vasopressor requirement to maintain a mean arterial pressure of 65 mmHg or greater and
Serum lactate level greater than 2 mmol/L (>18 mg/dL) in the absence of hypovolemia.
In 1991, a consensus task force developed initial definitions that focused on the prevailing view at the time that sepsis resulted from a host’s systemic inflammatory response syndrome (SIRS) to infection. SIRS was defined by the presence of two or more of four criteria, including body temperature, heart rate, respiratory rate, and white blood cell count. Despite their known limitations, these definitions remained mainly unchanged for almost three decades. In 2016, the Society of Critical Care Medicine and the European Society of Intensive Care Medicine sponsored a task force to review the definition of sepsis and its management guidelines (Sepsis-3).
Sepsis is now defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. This organ dysfunction can be represented by an increase in the Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score of two points or more. Another measure called quick SOFA (qSOFA), although less robust, may be more practical for providers diagnosing sepsis in the non-ICU setting. qSOFA incorporates altered mentation (GCS <15), systolic blood pressure of 100 mmHg or less, and respiratory rate of 22/min or greater.
Septic shock is a subset of sepsis with profound circulatory and cellular/metabolic dysfunction, associated with a higher risk of hospital mortality than with sepsis alone (40% versus 10%, respectively).
The term “severe sepsis,” previously defined as sepsis complicated by organ dysfunction, has been incorporated into the current definition of sepsis and abandoned.
A 32-year-old man undergoes unilateral hand transplantation. Tacrolimus for immunosupression is initiated. On routine evaluation 6 months postoperatively, a chronic increase in creatinine and a reduction in glomerular filtration rate is noted. Which of the following is the most appropriate next step in management?
A) Discontinuation of antihypertensive drugs
B) Discontinuation of dyslipidemia drugs
C) Initiation of oral corticosteroid therapy
D) Reduction of calcineurin inhibitor trough levels
E) Tissue biopsy of the transplanted hand
The correct response is Option D.
This patient is experiencing nephrotoxicity and chronic kidney disease (CKD) from tacrolimus. Calcineurin inhibitor nephrotoxicity is a well-known phenomenon posttransplantation, and close monitoring of kidney function is essential. There are multiple described pathways of kidney damage secondary to calcineurin inhibitors including irreversible damage to all compartments of the kidney (glomeruli, arterioles, and tubule-interstitium).
Krezdorn et al. evaluated 99 recipients of facial or extremity transplantation and concluded that kidney dysfunction represents a major complication posttransplantation in vascularized composite allografts and recommends pretransplant, peritransplant, and posttransplant strategies to reduce kidney damage. These include identifying patients at risk for CKD. Pretransplantation recommendations include treating existing renal conditions, avoiding hypotension and hypertension, limiting nephrotoxic drugs, limiting intravenous contrast, and avoiding hypovolemia. Peritransplantation recommendations include minimizing use of nephrotoxic agents, avoiding hypovolemia, and limiting ischemia time. Postoperative recommendations include minimizing tacrolimus exposure including reduction of trough levels, treating hypertension, treating hyperglycemia, treating dyslipidemia avoiding intravenous contrast, and limiting potentially nephrotoxic drugs such as nonsteroidal anti-inflammatory drugs.
Therefore, in this patient, tacrolimus troughs should be reduced. Initiation of oral corticosteroids is not appropriate. The patient should remain on antihypertensive and dyslipidemia drugs.
Which of the following patients is eligible to be an organ donor?
A) 30-year-old HIV-positive patient
B) 10-year-old whose family does not want to donate
C) 42-year-old with a diagnosis of Creutzfeldt-Jakob disease
D) 49-year-old with a recent diagnosis of stage IV melanoma
The correct response is Option A.
Minors are neither eligible for nor able to receive organ donation without the consent of a parent or guardian.
Creutzfeldt-Jakob disease or any other prion disease is a contraindication for organ donation of any kind.
Metastatic cancer is a contraindication for organ donation.
HIV status is no longer a contraindication to donate or receive an organ, provided the donor and recipient are both HIV positive.
An 81-year-old man with peripheral vascular disease undergoes coverage of exposed vascular prosthesis in the groin with a rectus femoris muscle flap. On postoperative day 2, the patient has sudden onset of chest tightness and becomes unresponsive, with no palpable pulse. CPR is promptly initiated. The defibrillator monitor shows ventricular fibrillation. Which of the following is the most appropriate next step after shock delivery (electrical defibrillation)?
A) Capnometry
B) Chest compressions for 2 minutes
C) Endotracheal intubation
D) Intravenous administration of adenosine
E) Pulse/rhythm check
The correct response is Option B.
According to current Advanced Cardiac Life Support (ACLS) guidelines, CPR should be resumed immediately after shock delivery, without pausing for a rhythm or pulse check. It should begin with chest compressions and continue for 2 minutes, after which the rhythm should be checked and the cycle (shock/CPR 2 min/check) repeated if there is no return of spontaneous circulation (ROSC).
Increasing emphasis has been placed on the importance of continuous “high-quality” chest compression (5 cm sternal depression, 100 to 120/min), to maximize tissue perfusion and probability of ROSC. A 30:2 compression:ventilation rate is recommended in the absence of an endotracheal or supraglottic airway. Otherwise, 10 breaths per minute should be delivered with continuous chest compressions.
There are no studies directly addressing the timing of advanced airway placement and outcome during resuscitation from cardiac arrest. Although insertion of an endotracheal tube during ongoing chest compressions is possible, in most instances intubation is associated with interruption of compressions for many seconds. Particularly, patients with witnessed cardiac arrest from ventricular fibrillation or pulseless ventricular tachycardia may benefit from a few uninterrupted cycles of CPR prior to placement of an advanced airway.
Adenosine is not indicated in the treatment of adult cardiac arrest.
Capnometry/capnography requires placement of an endotracheal tube.
A 45-year-old woman undergoes abdominoplasty in an ambulatory surgery center. After induction of general anesthesia, the patient’s end tidal carbon dioxide level increases, her heart rate increases to 160 bpm, and her arms become rigid. Which of the following are the physiologic abnormalities associated with this condition?
A) Hyperkalemia, hyperphosphatemia, metabolic acidosis
B) Hyperkalemia, hyperphosphatemia, metabolic alkalosis
C) Hyperkalemia, hypophosphatemia, metabolic acidosis
D) Hypokalemia, hyperphosphatemia, metabolic acidosis
E) Hypokalemia, hyperphosphatemia, metabolic alkalosis
The correct response is Option A.
Malignant hyperthermia is an inherited myopathy that is autosomal dominant with variable penetrance. Anesthetic agents that trigger malignant hyperthermia include halothane, enflurane, isoflurane, desflurane, sevoflurane, and succinylcholine. These agents trigger an earlier calcium release into the skeletal muscle, resulting in an abnormal buildup of calcium in the myoplasm. This flood of calcium causes the muscle to remain in a contracted state, producing high levels of lactic acid, carbon dioxide, phosphate, and heat. The resulting physiologic changes are metabolic acidosis, hypercapnia, hyperphosphatemia, and fever in a patient experiencing malignant hyperthermia. The treatment of malignant hyperthermia is discontinuation of volatile agents and succinylcholine, dantrolene, treatment of hyperkalemia and metabolic acidosis, and transfer to an acute care hospital.
Administration of prophylactic antibiotics is most appropriate for which of the following surgical procedures?
A) Abdominoplasty
B) Blepharoplasty
C) Brachioplasty
D) Mastopexy
E) Rhytidectomy
The correct response is Option D.
The ASPS recently published the first consensus statement/guidelines for antibiotic prophylaxis in plastic surgery which is based on comprehensive systematic review of the available evidence.
Systemic antibiotic prophylaxis is recommended for clean-contaminated, contaminated, or dirty plastic surgery of the head and neck, orthognathic/mandibular, septoplasty/rhinoplasty, hand and upper limb, and skin. Antibiotic prophylaxis is also recommended to reduce surgical-site infection for clean plastic surgery of the breast. Antibiotic prophylaxis is not recommended to reduce surgical-site infection in clean surgical cases of the head and neck, orthognathic/mandibular area, hand and upper limb, skin, and abdominoplasty.
With the exception of cosmetic breast surgery, clean operations have not been shown to benefit from routine antibiotic prophylaxis. Clean-contaminated and contaminated plastic surgical procedures do benefit from the use of antibiotic prophylaxis. The duration of antibiotic use should generally be limited to a single preoperative dose because studies have generally showed no benefit for longer term antibiotic prophylaxis.
As far as choosing the antibiotic, it should have activity against the most frequently encountered microorganisms in postoperative surgical-site infections. Cefazolin as a single dose preoperatively is the most commonly recommended agent and would be considered appropriate in most cases. In the event of allergy or intolerance, clindamycin or vancomycin may be appropriate alternatives.
A 42-year-old woman who is BRCA2-positive undergoes delayed reconstruction of both breasts with deep inferior epigastric artery perforator (DIEP) flaps. Medical history includes prophylactic mastectomy and failed implant reconstruction 3 months ago. After closure of the fascia of the rectus abdominis muscles, the triangle bounded by the latissimus dorsi, external oblique, and iliac crest is identified on each side. Infiltration of bupivacaine into which of the following planes is most likely to provide postoperative pain control of the abdominal flap donor site in this patient?
A) Between the external oblique and the internal oblique
B) Between the internal oblique and the transversus abdominis
C) Between the transversalis fascia and the peritoneum
D) Between the transversus abdominis and the transversalis fascia
E) In the deep subcutaneous tissues, superficial to the external oblique
The correct response is Option B.
The peripheral nerve block described is a transversus abdominis plane, or TAP, block. The lumbar (Petit) triangle, which is located at the lateral extent of the abdomen, is formed by the borders of the latissimus dorsi muscle posteriorly, the external oblique anteriorly, and the iliac crest inferiorly. Furthermore, the location can be estimated by the intersection of a horizontal line through the umbilicus and the vertical anterior axillary line. The intercostal nerves providing sensation to the anterior abdominal wall from T6 to L1 are located in the plane between the internal oblique and the transversus abdominis muscles. Long-acting local anesthetic infiltration in this plane is generally approached through the lumbar triangle. Multiple techniques have been described. These include visualized injection with the assistance of ultrasound guidance, catheter insertion under direct vision with surgical cutdown to the appropriate plane, and blind injection using a blunt needle, feeling for the two punctures of the external and internal obliques, respectively. Multiple studies have shown improved postoperative pain control in the abdominal donor site with this technique in breast reconstruction, and patients have demonstrated marked decreases in opioid consumption as well. The other options would be inappropriate for nerve block as the intercostal nerves are not found in those tissue planes.
A 61-year-old woman presents to discuss oncoplastic reduction mammaplasty. Medical history includes a femur fracture sustained during a fall 4 months ago. Recovery was complicated by a pulmonary embolus. Current medications include warfarin therapy. Her hematologist has recommended bridging therapy to prevent recurrent embolus. Which of the following is the most appropriate regimen to bridge anticoagulation with low-molecular weight heparin (LMWH) in this patient?
The correct response is Option D.
Managing anticoagulation in the perioperative period is challenging. The risk for thromboembolic phenomenon is transiently increased with any cessation in anticoagulation therapy. At the same time, this risk needs to be weighed against the risk for bleeding. For the patient described, who is high-risk for recurrent embolus (recent PE) and bleeding (due to the nature of the proposed procedure), these opposing risks need to be weighed carefully. They may be mitigated by a “bridging” strategy where short-acting agents provide prophylactic anticoagulation around the time of surgery while long-acting agents are held.
While the decision to adjust anticoagulation therapy in the perioperative period is controversial, the mechanism of bridging therapies is based on the known pharmacokinetic behaviors of anticoagulation agents. The half-life of warfarin is approximately 36 hours, so stopping warfarin prior to surgery will allow the therapeutic INR to return to normal levels by the day of surgery. To maintain therapeutic anticoagulation, low-molecular weight heparin (LMWH) may be initiated 3 days prior to surgery as the INR decreases. In the absence of other factors that predispose the patient to bleeding events, warfarin may be safely resumed 1 to 2 days after surgery.
Stopping warfarin 1 to 2 weeks prior to is unnecessary. Furthermore, a longer interval between cessation of warfarin and initiation of LMWH treatment may create a longer window where the patient is at risk for thromboembolic events.
Stopping warfarin the day of surgery and initiating LMWH the same day will place the patient at an increased risk for bleeding.
