Surgical Procedures/Special Populations 100 Q Flashcards
At what age is the MAC for sevoflurane the highest?
3 months
MAC is higher in pediatric patients. For sevoflurane, it is approximately 3.3% in neonates and 3.2% in infants 1-6 months of age. For children 6-12 months of age it is constant at 2.4%. The MAC for isoflurane in both infants and children is 1.6%.
What is the most common postoperative complication in the pediatric patient who has undergone tonsillectomy?
Bleeding
Although aspiration and tooth damage can occur due to tonsillectomy, the most common complication following tonsillectomy is bleeding which occurs in 0.5-7.5 percent of patients. Of those that experience bleeding, 75 percent of them occur within 6 hours postop.
Combined spinal anesthesia/general anesthesia in premature infants decreases all of the following except
the overall risk of postoperative apnea
Spinal anesthesia has been used as both the sole anesthetic for surgery, or as an adjunct to general anesthesia. Although spinal anesthesia is associated with a decreased risk for apnea in premature infants in the early phase following surgery, it does not decrease the overall risk for apnea across the entire postoperative period. Compared to general anesthesia, however, a combination of spinal anesthesia and general anesthesia provides for faster extubation because of a decreased need for narcotics, reduced need for muscle relaxants, and a reduction in the amount of volatile anesthetic needed.
Which location would be least appropriate for placement of an arterial line in a patient undergoing surgery on the distal aortic arch?
Left wrist
Because the left subclavian artery may be manipulated during the operation, which would disrupt monitoring in the left radial artery, monitoring pressures via another site would be preferred. The right radial is often used.
The most common surgical emergency in the neonate is
Necrotizing enterocolitis
Necrotizing enterocolitis is the most common surgical emergency in the neonate. Premature infants are at the greatest risk for developing it. Conditions associated with necrotizing enterocolitis include umbilical artery catheterization, systemic infections, perinatal asphyxia, hypotension, exchange blood transfusions, patent ductus arteriosus, cyanotic heart disease, respiratory distress syndrome, and hyperosmolar feedings.
In obese patients, the systolic blood pressure typically increases on average by about _____ mmHg for each 10 kg of excess adipose tissue.
3-4
Many obese patients exhibit systemic hypertension. The systolic pressure may increase 3-4 mmHg for each 10 kg of excess adipose tissue, while the diastolic pressure increases about half that amount.
Which statement represents an accurate understanding of anesthesia for middle ear surgery?
Local anesthesia is appropriate for middle ear surgery
Middle ear surgery can be performed under local or general anesthesia. The surgery requires a bloodless field, which is facilitated by local anesthesia. It also requires that the patient remain still, however, and that is best accomplished by general anesthesia. Postoperative nausea and vomiting is very common these patients. To help control bleeding, a head-up tilt of 15-20 degrees, normocapnia, and controlled hypotension may be used.
What is the most frequent cause of hospitalization in patients older than 65?
heart failure
The most frequent cause of hospitalization in patients older than 65 is heart failure.
Which of the following is most likely to be decreased in the micro-preemie?
serum sodium levels
Creatinine concentrations are increased for the first three weeks after delivery. The increase in creatinine clearance normally seen in full-term infants occurs more slowly in the micro-preemie. Micro-preemies exhibit reduced reabsorption of sodium and water in the proximal tubule, making them more susceptible to hyponatremia. Plasma potassium levels are increased in preterm infants for the first few days of life. Decreased cardiac output can increase potassium levels further, placing them at risk for cardiac dysrhythmias. The immature hepatic function associated with prematurity results in decreased synthesis of proteins required for drug metabolism. Decreased albumin levels result in an increase in the unbound, active form of many drugs.
Which of the following events would not be attributed to the effects of using methylmethacrylate to cement artificial components during a total hip arthroplasty? A. Pulmonary hypertension B. Systemic hypotension C. Impaired platelet aggregation D. Cardiovascular collapse
Impaired platelet aggregation
Methylmethacrylate use is associated with a decrease in blood pressure and possibly cardiovascular collapse due to vasodilation as well as pulmonary hypertension and a possible decrease in PaO2 due to embolization. Impaired platelet aggregation is not a finding associated with methylmethacrylate use.
What is the lower limit of autoregulation of cerebral blood flow in children of all ages?
60 mmHg is the lower limit of autoregulation of CBF in children of all ages.
Which of the following is not a risk factor for the development of preeclampsia? A. Nulliparity B. Obesity C. Smoking during pregnancy D. Advanced maternal age
Which of the following is not a risk factor for the development of preeclampsia?
Tobacco (smoking) is the most frequently abused substance among pregnant patients. Studies show that smoking is protective against the development of preeclampsia.
You have extubated a pediatric patient following tonsillectomy and the patient exhibits inspiratory stridor. You know that inspiratory stridor most commonly represents
upper airway obstruction
Inspiratory stridor results from upper airway obstruction. Lower airway obstruction results in expiratory stridor.
Preoperatively, all pediatric patients with mild asthma should receive
administration of a bronchodilator
Even if they are not exhibiting any symptoms, children with a history of mild to moderate asthma should be administered a bronchodilator preoperatively.
What is the advantage of combining opioids with local anesthetics in combined spinal/epidural analgesia?
it improves anesthesia without significant motor block
The combination of small doses of opioids and local anesthetics (fentanyl 10-15 mcg and bupivacaine 1.25-2.5 mg) can provide excellent analgesia without producing significant motor block.
An obstetric patient has a mechanical heart valve. Which of the following statements is most consistent with recommended anticoagulation objectives for this patient?
warfarin should not be used past 36 weeks gestation
Anticoagulation is a concern for parturients presenting with mechanical prosthetic valves. Current anticoagulation options for pregnancy per the American College of Cardiology are as follows: 1. Warfarin should be continued until week 36; Convert to unfractionated heparin or low molecular-weight heparin at that point 2. Use low molecular-weight heparin for entire pregnancy 3. Use low molecular weight heparin or unfractionated heparin from 6 to 12 weeks and also after week 36; use warfarin from 12 to 36 weeks.
Which of the following precautions should be taken when anesthetizing a patient undergoing CO2 laser vaporization of condylomatous lesions? (select two)
goggles and smoke evacuation system
When viral tumors such as condylomatous lesions are vaporized by laser, intact viral particles can be recovered from the plume which warrants the use of gloves, a smoke evacuation system, high-efficiency filter masks, and protective goggles.
Which of the following would speed the rate of rise in the FA/FI in an infant?
An increase in cardiac output
The pharmacokinetics and pharmacodynamics of inhalation anesthetics in the pediatric population differs some from that of adults. The rate of rise of FA/FI (the ratio of the alveolar concentration of the anesthetic to the inspired concentration), also known as the washin, depends upon six parameters: the inspired concentration of the gas, alveolar ventilation, the functional residual capacity, cardiac output, the solubility of the gas, and the alveolar to venous partial pressure gradient of the anesthetic. In adults, an increased cardiac output slows the rate of rise of FA/FI. However, in neonates and infants, an increase in cardiac output speeds up the rate of rise of FA/FI. It is believed that this is due to differences in blood distribution. The vessel-rich group comprises a greater proportion of the body mass (18% compared to only 8% in adults). As a result, more of their cardiac output is distributed to the vessel-rich group.
Administration of a large dose of which of the following drugs would be most likely to produce seizures in a pediatric patient?
flumazenil
Flumazenil can be used to antagonize benzodiazepines in pediatric patients. It should be noted that the short half-life of flumazenil has been associated with re-sedation in children ages one to five. Larger doses of flumazenil have been associated with seizures in pediatric patients.
You need to perform a rapid sequence induction for a pediatric patient with a full stomach. What neuromuscular relaxant would have the fastest onset?
succs
Succinylcholine is a depolarizing neuromuscular blocking agent with the fastest onset and shortest duration of action. The intravenous dose is 3-4 mg/kg in neonates, 2 mg/kg in infants, and 1 mg/kg in teenagers. The increased intravenous dose requirements in younger children is presumed to be due to a higher volume of distribution. Paralysis typically occurs in less than one minute and lasts for about 5 minutes. An intramuscular dose of 4 mg/kg will produce paralysis within 1-2 minutes but can last as long as twenty minutes.
When referring to a premature infant, the term very low birth weight (VLBW) indicates a birth weight less than
1500 g
Prematurity is defined as a birth that occurs before 37 weeks gestation. Premature infants that weigh less than 2500 grams are classified as low birth weight. Premature infants that weigh less than 1500 grams are classified as very low birth weight. Premature infants that weigh less than 1000 grams are classified as extremely low birth weight (ELBW). Some practitioners use the term ‘micro-preemie’ to refer to very low and extremely low birth weight infants.
A patient with a blunt aortic injury from a motor vehicle accident exhibits increased pulmonary vascularity and a normal heart size on chest x-ray. What injury-induced pathologies would most likely produce this?
ventricular septal defect
Increased pulmonary vascularity and a normal heart size on chest x-ray in a patient with blunt chest trauma could be indicative of a ventral septal defect caused by trauma.
What is the most common complication of central neuraxial blockade in the obstetric patient?
hypotension
Due to the sympathectomy it produces, hypotension is the most common complication of central neuraxial blockade in the obstetric patient.
What is the primary advantage of using an Andrews frame for lumbar spine surgery?
decreased bleeding
The Andrews frame secures the patient in knee-chest position with the abdomen hanging freely which reduces intra-abdominal pressure and contributes to decreased blood loss. Because the legs are below the level of the heart, venous return is decreased and severe hypotension can result.
Micro-preemies are especially prone to exhibiting
thrombocytopenia
Thrombocytopenia (platelet count less than 150,000) occurs in approximately 70% of micro-preemies. As a result, preoperative evaluation of the micro-preemies should include a platelet count and verification that platelets are available for administration. Micro-preemies often exhibit insulin resistance. Most micro-preemies are administered blood transfusions in the first few weeks of life due to an anemia of prematurity. The decreased sodium reabsorption in premature infants is associated with hyponatremia.
Risk factors for deep vein thrombosis include all of the following except
factor 8 deficiency
A BMI of 60 or more, evidence of venous stasis, central obesity, and obesity hypoventilation syndrome or obstructive sleep apnea are significant risk factors for deep vein thrombosis.
Intentional collapse of the lung on the operative side and one-lung ventilation during thoracic surgery results in
widening of the PA-a (alveolar to arterial) gradient
Intentional lung collapse on the operative side is commonly used to enhanced visualization of the operative field. Side effects are primarily due to the large intrapulmonary shunt that develops because the upper lung is still being perfused but not ventilated. The PA-a gradient widens and hypoxemia typically ensues. One-lung ventilation does not appreciably change the arterial CO2 tension.
Bradycardia is associated with repeat doses of _____ in pediatric patients.
succinylcholine
Bradycardia and potentially asystole are potential side effects of succinylcholine re-administration, particular in children.
A patient with a pacemaker with a program code of VVI has a heart rate of 104 and you see pacer spikes on the ECG. You would most accurately assume that
the pacemaker ventricular sensing is faulty
This programming code indicates that this pacemaker is designed to pace and sense in the ventricle and inhibits its own activity if it senses a spontaneous depolarization. Because the spontaneous heart rate is higher than is normal for a pacemaker and pacemaker spikes are still visible, the pacemaker is obviously failing to sense the spontaneous beats.
Which is true of pain associated with the second stage of labor?
It is somatic
Pain from the first stage of labor is visceral, involves spinal cord segments T10-L1, and is caused by traction on the round ligament, cervical dilation, and uterine contractions. Pain from the second stage of labor is somatic, includes the S2-S4 spinal cord segments, and is caused by stretching of the perineum, fascia, skin, and subcutaneous tissue.
Which of the following statements is false regarding kyphoplasty and vertebroplasty?
Kyphoplasty is more likely to result in cement extravasation than vertebroplasty
Radiculopathy, spinal claudication, and paraplegia are potential neurologic complications of vertebroplasty. Vertebroplasty is more likely to result in extravasation of the cement because the cement used in vertebroplasty is less viscous than that used for kyphoplasty. The patient is positioned prone for the actual procedure and should remain supine for 3-5 hours after the procedure for evaluation of neurologic status and careful observation for bleeding. General anesthesia and IV sedation are both acceptable techniques for these procedures.
You have administered an epidural test dose. Which findings are consistent with inadvertent intrathecal injection?
Warmth and tinging in the legs
The intravenous injection of 15 mcg of epinephrine will increase the heart rate by about 10 beats per minute and the systolic blood pressure by at least 15 mmHg. The intrathecal injection of the lidocaine will produce warmth and tingling in the patient’s legs and feet within 2-3 minutes.
What are the components of the triple-H therapy used in the treatment of patients with symptomatic cerebral vasospasm? (select three)
Triple H therapy refers to Hypervolemia, Hypertension, and Hemodilution. This term is in reference to the treatment of patients with symptomatic vasospasms.
Pediatric obesity is associated with an increased incidence of all of the following except
insulin sensitivity
Pediatric obesity results in an increase in blood volume and cardiac output and can lead to systemic hypertension, left ventricular hypertrophy, and atherosclerosis at an early age. Half of severely obese pediatric patients will exhibit insulin resistance and metabolic syndrome. Twenty percent will exhibit gastroesophageal reflux. Infiltration of the liver by fatty tissue can lead to nonalcoholic fatty liver disease and elevated liver enzymes.
When referring to a premature infant, the term low birth weight indicates a birth weight less than
2500g
Prematurity is defined as a birth that occurs before 37 weeks gestation. Premature infants that weigh less than 2500 grams are classified as low birth weight. Premature infants that weigh less than 1500 grams are classified as very low birth weight. Premature infants that weigh less than 1000 grams are classified as extremely low birth weight (ELBW). Some practitioners use the term ‘micro-preemie’ to refer to very low and extremely low birth weight infants.
