Preoperative Evaluation and Perioperative Care Flashcards
Increased risk factors for pulmonary morbidity include…
alcohol abuse, cigarette smoking, poor preoperative nutrition, underlying pulmonary disease, age, abdominal/thoracic incisions
What is The American College of Cardiology/American Heart Association (ACC/AHA) algorithm for perioperative cardiovascular evaluation of noncardiac surgery?
Is pre-op CXR necessary for noncardiothoracic elective surgery?
Preoperative chest radiography is of limited benefit in patients who do not have baseline dyspnea or underlying pulmonary disease.
In a 75-year-old patient with congestive heart failure who is to undergo an elective ventral hernia repair, perform an adequate history and physical examination and independently stratify perioperative cardiac risk.
- functional capacity: ask if they can climb stairs
- assess for valvular dysfunction: listen for murmurs
- assess current CHF: pts w/ CHF dx need echo or cards eval
In an 80-year-old man with chronic obstructive pulmonary disease who is undergoing an emergency inguinal hernia repair, be able to independently discuss factors to decrease perioperative pulmonary morbidity.
- improve nutrition
- IS and chest PT decrease morbidity
- selective NGT decompression can be considered
- laparoscopic approaches decrease pulm complications
What tool can be used to help guide surgeons when counseling patients and families on risks of postoperative morbidity, length of hospital stay, and risk of discharge to a skilled nursing facility?
The NSQIP risk calculator takes into account the patient’s functional status, the planned operation, and other comorbidities. It can help guide surgeons when counseling families on some general postoperative risks.
How do long-term exogenous steroids affect the adrenal glands?
Suppresses the natural corticotropin–adrenocorticotropic hormone–corticosteroid loop axis and causes adrenal atrophy. The adrenal atrophy causes a blunted response when a new stress (surgery) is present.
What is the half-life of warfarin?
40 hours
What is the half-life of apixaban?
this direct Xa inhibitor has a half-life of around 8-12 hours
What is the half-life of aspirin?
This COX inhibitor has a half-life of 2.5-4 hrs
What is the half-life of clopidogrel?
This ADP inhibitor has a half-life of about 6 hours.
In the preoperative workup of a patient for elective inguinal hernia (minor procedure), you find he has been on 2 mg/d of prednisone for 1 week. What do you do?
Stress-dose steroids are not indicated for patients on short-term steroids (< 3 weeks) or for those on low-dose (< 5 mg/d) steroids and undergoing procedures with minimal stress.
What patient populations may be on anticoagulants?
a-fib, MI, cardiac stents, vascular stents, DVT, PE, stroke, TIA, PVD
In equivocal cases, what lab test can be obtained to determine HPA axis impairment?
early-morning random cortisol <5 mcg/dL
What induction agent is contraindicated in patients with HPA axis impairment?
etomidate can further suppress HPA axis and reduce serum cortisol level
When should anticoagulants be stopped before surgery?
Stop warfarin for 5 days pre-op
Stop PO antithrombin and anti-Xas 2 days pre-op
A patient with a bare metal coronary stent can go to operating room after , and a patient with a drug-eluting stent can be operated on after .
4 weeks
6 months
How long does a pt w/ a new postop DVT need to be on anticoagulation?
12 weeks (6 months if no inciting event)
Prevent or mitigate postop pain.
- Opioids are the most widely used treatment of postoperative pain.
- Patient-controlled analgesia (PCA) benefits include decreased delay in patient access to pain medication, decreased likelihood of overdose by programming small bolus doses with a fixed lockout interval, enhanced monitoring, and ability to titrate.
- Administration of NSAIDs can reduce the dose of opioid required and decrease the occurrence of opioid-related side effects. Use caution in colorectal pts as they can increase leak. Use caution in coagulopathic, kidney failure, and ulcer pts as NSAIDs can exacerbate these issues.
Use physiologic parameters to assess the hemodynamic stability of a postoperative patient to guide ongoing resuscitation efforts.
- Heart rate (HR): Maintain between 60-100 bpm.
- Oxygen saturation: Maintain > 92 percent.
- Urine output: Maintain > 0.5 mL/kg/hr.
- Lactate and base deficit: Monitor serum lactate every 4 hours to ensure end-organ perfusion is adequate or improving with resuscitation.
Given surgical patients with hyperglycemia, understand glycemic management through appropriate therapeutic choices.
- Surgery and general anesthesia induce a neuroendocrine stress response with release of counter-regulatory hormones that result in metabolic abnormalities including insulin resistance.
- For patients who develop hyperglycemia, supplemental short or rapid-acting insulin may be administered subcutaneously, based on frequently measured capillary “fingerstick” glucose levels.
- Optimal perioperative glucose targets are between 140 and 180 mg/dL.
Presentation and dx of postop urinary retention.
- Patient risk factors include older age, male gender, and preexisting medical comorbidities such as benign prostatic hypertrophy or neuropathy.
- Procedural risk factors include anorectal surgery, inguinal/femoral hernia repair, excessive fluid administration, and the anesthetic agents used.
- Non-invasive bladder ultrasound should be used to evaluate for possible urinary retention in any patient unable to void 4 hours after surgery.
- Patients with large volume retention (>600 mL of urine) on ultrasound should have a Foley catheter kept in place to decompress the bladder.
Presentation and dx workup of postop fever
- Postoperative fever (> 38°C, 100.4°F) is common in the first few days after surgery and often resolves spontaneously. TIssue trauma causes cytokine release.
- The MC infectious causes of postoperative fever include SSI, PNA, UTI, and CLABSI.
- Basic laboratory studies, chest x-ray, urinalysis, blood and urine cultures are appropriate for initial workup of a postoperative fever. However, they are not always indicated, and their utility should be determined in the context of a thorough history and physical examination.
Evaluate and treat a patient who reports new onset lower extremity edema or pain
- Inquire about symptoms such as pain, numbness, tingling, etc. Obtain a detailed history of CV dz, PVD, or coagulopathy.
- Physical examination should focus on the CV system
- Assess extremities for pulses, motor/sensory deficits, and edema.
- Utilization of duplex US is an effective adjunct to diagnosis.
- Acute arterial thromboembolism is a surgical emergency
- Risk of VTE can be minimized with mechanical methods (graduated compression stockings) and PPX dose pharmacologic agents (i.e. heparin or lovenox).
Recognize and treat postoperative hemorrhage
- Tachycardia, hypotension, oliguria (urine output <20 mL/hr), confusion, and increasing abdominal pain may all signal postop intra-abdominal bleeding.
- Suspicion hemorrhage - resuscitation, large-bore IVs, Foley, NPO status.
- HDS patients may be managed conservatively with transfusion as indicated.
- Onset of hemodynamic instability prompts operative intervention to locate and control the source of hemorrhage.
A 65-year-old woman with a history of myocardial infarction (last year) as well as hypertension presents for an elective ventral hernia repair. What is your approach to assess her perioperative cardiac risk?
- This is an elective procedure. Emergencies go.
- Ask if she has had coronary revasc within 5 years, had a recent coronary evaluation (angio or stress test), or has new sx
- If recent revasc w/o new sx, proceed to OR
- If recent favorable w/o new sx, proceed to OR
- Ask about ability to climb stairs
- EKG and echo if no recent
- Predictors: unstable coronary sx, decompensation, arrhythmias, severe valvular dz - consider delay, med mgmt, or coronary eval
A 75-year-old man presents for his preoperative appointment for planned femoral popliteal bypass. He has a history of coronary artery disease and angina. How would you assess his cardiac risk for surgery?
- Perform a clinical assessment, including assessing for murmurs, and obtain the patient’s metabolic equivalents (METs) score.
- Ask about recent revasc, coronary eval, recurrent/new sx
- Order electrocardiogram and an echocardiogram.
- Ask about ability to climb stairs
- Refer to cards for workup if new symptoms or signs of decompensation, new coronary symptoms, arrhythmias, valve dz
What is the difference between pressure and volume controlled ventilation?
During volume-limited ventilation, inspiration ends after delivery of a set tidal volume. During pressure-limited ventilation, inspiration ends after delivery of the set inspiratory pressure.
What are some adverse pulmonary effects of positive pressure ventilation?
pulmonary barotrauma, ventilator-associated lung injury, intrinsic positive end-expiratory pressure (auto-PEEP), heterogenous ventilation, altered ventilator/perfusion mismatch, diaphragmatic muscle atrophy, respiratory muscle weakness, and diminished mucociliary motility
What are some non-pulmonary negative associations with positive pressure ventilation?
reduce cardiac output and impair hemodynamic monitoring
gastrointestinal stress ulceration, decreased splanchnic perfusion, gastrointestinal hypomotility, fluid retention, acute renal failure, increased intracranial pressure, inflammation, and disordered sleep
discuss the factors that contribute to abnormal pulmonary physiology after an operative procedure and identify patients at risk for severe postoperative respiratory failure
abdominal distention, painful upper abdominal incision, obesity, advanced age, strong smoking history with associated chronic obstructive pulmonary disease, prolonged supine positioning, and fluid overload leading to pulmonary edema
What is type 1 respiratory failure?
hypoxic failure - results from abnormal gas exchange at the alveolar level
What is type 2 respiratory failure?
hypercapnia, and affected patients are unable to eliminate carbon dioxide adequately
What is the most common postop respiratory problem? Why does it occur? What is the pathophysiology?
atelectasis - a result of the anesthetic, abdominal incision, and postoperative narcotics
the alveoli in the periphery collapse and a pulmonary shunt occurs
apnea; stridor; severely depressed mental status; flail chest; and inability to clear secretions and/or severe trauma to the mandible, larynx, or trachea - all are indications for what in addition to hypoxia or hypercarbia?
mechanical ventilation
Assessment for mechanical ventilation is required for what general respiratory disorders?
acute/chronic hypoxia or hypercarbia
What vent settings can improve oxygenation?
PEEP and FiO2
What vent settings can improve hypercarbia?
increasing respiratory rate or tidal volume
What are common mechanical reasons for early post-intubation ventilation failure?
inadequate sedation, mainstem intubation, endotracheal tube cuff leak, and accidental extubation
In pts with ARDS, how do you determine tidal volume?
use low tidal volume ventilation:
4-8 mL/kg predicted body weight
predicted BW based on height
What is the most accurate means of confirming endotracheal tube placement in the trachea in noncardiac arrest patients?
End-tidal carbon dioxide determination (either colorimetric or quantitative capnography)
it should be used with every intubation
Currently mechanically ventilated patients are especially vulnerable during what two events?
transport, turning - conscious effort for tube protection is needed at these times
What is the definition of prolonged mechanical ventilation? What is its association with mortality?
21 days on the vent
40-60%
What is the difference of quality of life in survivors of critical illness requiring prolonged mechanical ventilation?
lower quality of life, even compared to age/gender matched peers
What are three weaning parameters for mechanical ventilation?
- spontaneous breathing trials
- RSBI
- NIF
What is a spontaneous breathing trial?
done daily
breathing through an endotracheal tube either without any ventilator support or with minimal ventilator support (eg, low level of pressure support, automatic tube compensation, or continuous positive airway pressure)
What is RSBI?
RSBI is the ratio of respiratory frequency to tidal volume. Patients who cannot tolerate independent breathing tend to breathe rapidly and shallowly. There is an increased probability of successful weaning if the RSBI is <105 breaths/min/L.
What is NIF as it pertains to vent weaning?
NIF is a coached maneuver where the patient is prompted to draw a maximum inspiration against an occluded airway. Global assessment of strength of respiratory muscles. The goal is to be within the normal range and have less than 10 cm H2O of variability between multiple inspiratory efforts.
You are called to see a 67-year-old man who is hypoxic (oxygen saturation of 80%) following a left-sided colectomy for diverticulitis. He is somnolent with a blood pressure of 140/80 mm Hg and a heart rate of 98 beats/min. What steps do you take with this patient?
- ABCs
- differential dx of hypoxia - narcotics, PNA, MI, CHF, obstruction
- workup hypoxia - CBC, BMP, ABG, CXR, EKG, troponin
- can they be bagged?
- if not, RSI
A 32-year-old motorcyclist is dyspneic following being hit by an automobile. He is now more alert and has a cervical collar in place. His blood pressure is 130/95 mm Hg, his heart rate is 133 beats/min, his respiratory rate is 32/min, and his oxygen saturation is 88%. Weight is estimated to be 160 kg. What is your approach to evaluating this patient further?
- standard trauma workup
- ABCs
- secondary exam
- CXR, FAST
A 75-year-old man is the restrained driver in a motor vehicle accident. Past medical history is significant for atrial fibrillation on warfarin anticoagulation. On arrival at the trauma center, his score on the Glasgow Coma Scale is 15. Vital signs are within normal limits. Computed tomography of the head reveals a small subdural hemorrhage without mass effect or midline shift. He has sustained three rib fractures as well and is admitted to the surgical intensive care unit for monitoring. Two hours after admission, a nurse calls you to the bedside because of concern about altered mental status. How do you evaluate and manage this patient?
Perform an airway assessment that includes airway protection, work of breathing, recent medications, and ruling out pneumothorax.
Consider the likelihood of worsening intracranial hemorrhage as a cause of respiratory distress.
An 84-year-old woman has had a partial colectomy with colostomy for perforated diverticulits . On postoperative day 4 she develops a temperature of 101ºF, a blood pressure of 70/40 mm Hg, and a heart rate of 121 beats/min. Her past history is significant for taking 2 mg/d of prednisone for rheumatoid arthritis. How would you evaluate and manage this patient?
This patient presents with fever, hypotension, and peripheral vasodilation. This is a hallmark of a lack of steroid response due to chronic prednisone therapy.
The patient should also have a workup for other causes of hypotension, including sepsis, cardiogenic shock, and pulmonary embolism.
Clinical resolution of hypotension with administration of intravenous hydrocortisone confirms the diagnosis. A random cortisol level is not necessary before treatment.
A 53-year-old man with history of type 1 diabetes presents to the hospital with an anterior wall myocardial infarction. Treatment entails placement of two drug-eluting stents and administration of heparin, clopidogrel, and aspirin. On the second day of his admission, he develops right upper quadrant pain and is diagnosed with acute cholecystitis. How would you manage this patient’s surgical condition and anticoagulation?
- Anticoagulation is needed to keep his cardiac stents from clotting, and the surgical condition should be temporized. No interruption for 6 months.
- Cholecystostomy tube and antibiotics.
- DC home on oral anticoag (dabigatran, apixiban, rivaroxaban), aspirin, clopidogrel.
- He should undergo laparoscopic cholecystectomy after 6 months. At that time, the novel oral anticoagulant should be stopped 2 days before surgery and the clopidogrel 7 days before surgery. The aspirin should be continued throughout the entire perioperative period.
A 40-year-old man with a history of ulcerative colits is scheduled for a total abdominal colectomy. The patient has been treated with 10 mg/d of prednisone for the past 2 years. How would you manage this patient’s steroids over the perioperative period?
Supplemental perioperative steroids are given to patients who have been on chronic steroid therapy. These patients are expected to have suppression of the HPA axis and are unable to mount a steroid stress response.
Stress-dose steroids are given in the form of short-acting intravenous cortisone (hydrocortisone).
The stress-dose steroids are given until the patient’s surgical stress resolves.
Two most common neuro/psych complications postop
pain, delirium
What method of opioid delivery has been shown to provide superior pain control and patient satisfaction?
PCA
What are some of the proven benefits of epidural anesthesia?
- more complete analgesia than PCA
- decreased rates of pulmonary complications
- decreased rates of ileus
What are the pros/cons of postop NSAID use?
- no respiratory depression, addiction potential, AMS, ileus
- association w/ bleeding, gastric ulcers, AKI
- no bleeding/gastritis found in postop use w/ lap chole, hysterectomy, and inguinal hernia repair
What is the most reliable marker of cardiac health?
exercise tolerance
What intra-abdominal pressure in laparoscopic cases can reduce venous return and subsequently decrease CO if maintained for a prolonged period?
20 mmHg
What procedural factors are associated with delirium risk?
operative time greater than 2 hrs, prolonged use of restraints, presence of urinary catheter, addition of more than 3 meds, reopration
Tachycardia can be caused by catecholamine surge, which can incite plaque rupture, causing MI. What can be done to prevent this, reduce MI and mortality from MI by 30% in vascular patients?
perioperative beta blockade, only in patients with hx of cardiac ischemia
In patients with normal renal function, what are some good physical exam findings of fluid status?
mental status, urine output, heart rate, and blood pressure
What is the initial management of oliguria postop?
- urinary catheter and crystalloid fluid challenge
- get urinalysis
- rule out shock (normal vitals)
- rule out CHF (rales, edema, CXR w/ edema)
Serum sodium is used as a marker to determine what in the intravascular space?
free water
- hypoNA - ADH, use isotonic fluids
- hyperNA - free water replacement PO
In critically ill postop patients, what prophylaxis must be used to prevent upper GI bleeding or perforation?
H2 blocker for stress ulcer ppx; not needed in elective uncomplicated operations
What factors other than surgery and inflammation can worsen ileus in postop patients?
narcotics, electrolyte derangements, immobility
use thoracic level epidurals, maintain normal lytes
When can early postop feeding be attempted?
healthy patients undergoing elective abdominal surgery
What is the timeframe for early postop bowel obstruction?
SBO within 30 days - 90% are inflammatory adhesions, next most common are internal hernias (suspect in bowel anastomosis or colostomy)
What class of surgical procedure does not require antibiotic prophylaxis?
class 1 - clean - uninfected wound w/o enteral contamination or break in procedure
What kind of abx are often required for class III wounds? Is it prophylactic?
No. Therapeutic abx are usually indicated in these cases.
What precaution should be taken for class IV wounds?
these wounds have necrotic and devitalized skin; therapeutic abx are often used to target relevant organisms, and the skin should not be closed
What should you be suspicious of in a patient with normal medical history except for bleeding at the dentist or menorrhagia?
undiagnosed hematologic disease
At what point can prophylactic platelet transfusion be used in a surgical patient who is not bleeding or about to undergo surgery?
20K
In uremia caused platelet dysfunction, what drug can be used?
desmopressin - helps release vWF from endothelium
What is the PTT goal for treatment of DVT?
1.5 to 2x normal
When should oral anticoagulation be started after periop VTE? How long should it be continued?
start within 24 hrs, continue for 3-6 months
Which anticoagulation agent should be used in pregnancy for VTE?
heparin, does not cross placenta
How should therapeutic heparin be managed perioperatively?
stop 6 hrs preop, restart 12 hrs postop (no bolus needed); elective surgery should be deferred until 3 months
What is the age requirement for preoperative screening for EKG and CXR?
men at 40, women at 55
