Lippincott's Anesthesia Review: 1001 Questions and Answers
Chapter 21. Miscellaneous Topics
Paul Sikka and Thomas Halaszynski
1. A 90-year-old male is presented to the operating room for surgical repair of a right femoral neck fracture. His medical history is significant for chronic obstructive pulmonary disease (60 pack year smoking history) and is prescribed 4 L/min of continuous home oxygen. A note from his pulmonologist states that this patient is a high-risk candidate for general anesthesia and will prove to be difficult to wean from mechanical ventilation. To properly assess the respiratory risk for this patient, which of the following will provide the least beneficial value?
A. Stat pulmonary function tests
B. Baseline chest radiograph
C. Thorough history and physical examination
D. Baseline arterial blood gas
2. A 65-year-old female, status post coronary artery bypass grafting (CABG) 2 weeks ago, is scheduled for a fem-fem bypass. The patient has been recovering well since her routine two-vessel cardiac bypass surgery, but continues to experience intermittent claudication symptoms of the left lower extremity. The surgeon informs you that the patient was scheduled for the vascular bypass surgery several weeks ago, but could not undergo the surgery due to her poor cardiac function. Now that cardiac pathology has been resolved, he would like to proceed with the vascular procedure as soon as possible. Your recommendations to the vascular surgeon would be
A. Provided she is without cardiac symptoms, the vascular surgery can now be performed
B. The vascular procedure should be delayed for another 2 weeks
C. The surgeon needs to obtain cardiology clearance prior to the procedure
D. The vascular surgery should be delayed for at least 6 months following the CABG procedure
3. A 76-year-old female comes to the preadmission clinic for anesthetic evaluation prior to a right total hip replacement (THR) scheduled in 2 weeks. Her medical history is significant for coronary artery disease (status post stent placement 6 months ago) and baseline unstable angina one to two times per month. The patient indicates that her symptoms are relieved by sublingual nitroglycerin. A recent echocardiogram (30 days prior) showed an ejection fraction of 30% along with evidence of inferior-wall-motion abnormality. Examination of the most current EKG shows diffuse T-wave inversions with a heart rate of 60 to 65 bpm (on metoprolol) and a blood pressure of 125/60 mm Hg. In addition, the patient has severe chronic obstructive pulmonary disease, is dependent upon 2 L/min home O2, and has obstructive sleep apnea (on bi-level positive-airway pressure at night). In order to maximize the preoperative condition of this patient, you will order all of the following diagnostic tests/examinations/consultations, except
A. Repeat the cardiac catheterization and confirm whether or not the patient requires coronary artery bypass grafting (CABG) surgery prior to THR
B. Communicate with cardiologist to confirm patient is medically optimized
C. Would not introduce any more coronary interventions unless new symptoms are present
D. Maintain hemodynamic stability during THR surgery
4. A 74-year-old patient undergoes a lumbar sympathetic blockade to improve blood flow after sustaining a frostbite injury to the left lower extremity. Clinical findings that would suggest a successful block include
A. Inability to dorsiflex the foot
B. Piloerection on the legs
C. Numbness from the knee to the toes
D. Temperature increase in the legs
5. The nerve that needs to be blocked to obliterate the gag reflex when applying pressure to the posterior portion of the tongue during an awake fiberoptic intubation is the
A. Recurrent laryngeal nerve
B. Glossopharyngeal nerve
C. Superior laryngeal nerve
D. Inferior laryngeal nerve
6. A 74-year-old patient undergoes a stellate ganglion block secondary to extreme hot flashes and night awakenings secondary to a long history of breast cancer. Potential complications include all of the following, except
A. Recurrent laryngeal nerve paralysis
B. Subarachnoid block
D. All of the above
7. Incorrect statement regarding metabolic equivalent (MET) is
A. 1 MET = consumption of 3.5 mL O2/min/kg of body weight
B. 5 MET = climbing one to two flights of stairs, dancing, or bicycling
C. 4 MET = equivalent to gardening
D. 2 MET = equivalent to getting dressed
8. A 35-year-old G2P1 at 30 weeks gestational age is coming to the OR within the next hour for open reduction internal fixation of an ankle fracture. The patient’s blood type is O+ and has hematocrit of 32. All of the following should be arranged, except
A. Prepare for a perioperative obstetrical (OB) consultation
B. Type screen and crossmatch for blood
C. Intraoperative RhoGam injection prior to surgery start
D. Prepare for perioperative fetal monitoring
9. An E-cylinder of oxygen with a pressure of 1,000 psig and being used at a rate of 2 L/min will run out in
A. 2 hours
B. 3 hours
C. 4 hours
D. 6 hours
10. A 49-year-old patient is undergoing a craniotomy for tumor resection. Intraoperatively, the patient received drugs including thiopental, vecuronium, isoflurane, and fentanyl. The patient is brought to the postanesthesia care unit with a HR of 58/min, BP of 196/96 mm Hg, and oxygen saturation of 98%. A few moments later the patient has two episodes of vomiting. You would then
A. Give ondansetron
B. Give metoclopramide
C. Give fentanyl
D. Call the neurosurgeon
11. Parkinsonism is associated with
A. Loss of dopaminergic neurons alone
B. Loss of cholinergic neurons alone
C. Loss of cholinergic and increase in dopaminergic activity
D. Loss of dopaminergic and increase in cholinergic activity
12. A 36-year-old patient with multiple sclerosis (MS) is to undergo an exploratory laparotomy. The best anesthesia technique to prevent a flare-up of symptoms would be
A. General anesthesia with endotracheal intubation using a nondepolarizing muscle relaxant
B. General anesthesia with endotracheal intubation using a depolarizing muscle relaxant
C. Spinal anesthesia
D. Combined spinal–epidural anesthesia
13. The primary aim of using succinylcholine for anesthesia for electroconvulsive therapy (ECT) is to
A. Prevent loss of airway
B. Control excessive seizure activity
C. Control cardiovascular sympathetic discharge
D. Prevent musculoskeletal injuries
14. Cardiovascular response following an electroconvulsive therapy (ECT) is characterized by
A. An initial parasympathetic discharge followed by a sympathetic discharge
B. An initial sympathetic discharge followed by a parasympathetic discharge
C. Sympathetic discharge alone
D. Parasympathetic discharge alone
15. Nondepolarizing muscle relaxants block which of the following receptors?
16. Ipratropium acts to relieve bronchospasm via which of the following receptors?
17. All statements regarding neostigmine are true, except
A. It inhibits acetylcholinesterase
B. It inhibits pseudocholinesterase
C. It shortens the duration of action of succinylcholine
D. It can cause neuromuscular blockade
18. When using neostigmine to reverse neuromuscular blockade in the presence of severe renal disease, you would use the following dose when compared to a normal patient
19. Fastest acting neuromuscular reversal agent is
20. Highest plasma concentration of a local anesthetic will occur if infiltrated via which of the following routes?
D. Brachial plexus
21. A 27-year-old 38 weeks pregnant female presents with painless vaginal bleeding. The best step in the management of this patient is
A. Direct examination with a vaginal speculum and then take the patient to OR for cesarean section
B. Cesarean section
C. Bed rest and observation
D. Epidural after bleeding stops
22. The most frequent cause of delayed emergence in the postanesthesia care unit is
A. Residual anesthetic agents
23. Emergence from inhalational anesthetics is primarily dependent on
A. Type of agent used
B. Cardiac output
D. Adjunct anesthetic drugs
24. Emergence from intravenous anesthetics is primarily dependent on
B. Elimination half-life
C. Type of agent used
D. Hepatic or renal disease
25. A 35-year-old patient is brought to the postanesthesia care unit (PACU) after undergoing an appendectomy. His anesthetics included propofol 140 mg, isoflurane 2.0 MAC, vecuronium 6 mg, and morphine 6 mg. In the PACU, the patient is shivering. The most likely cause of his shivering is
A. Use of isoflurane
B. Presence of infection and dehydration
C. Use of unwarmed fluids
D. Use of morphine
26. Best method to prevent shivering is
A. Use warmed fluids
B. Warming lights
D. Forced-air-warming device
27. A 56-year-old patient, with a tracheostomy, is undergoing a radical neck dissection under general anesthesia. The induction is uneventful and you proceed to replace the tracheostomy tube with an endotracheal tube for the procedure. The patient’s peak airway inspiratory pressures increase suddenly. The most likely diagnosis is
C. Malposition of the endotracheal tube (ETT)
D. Patient attempting to breath
28. Laryngospasm (LS) is due to stimulation of the
A. Superior laryngeal nerve
B. Internal laryngeal nerve
C. Recurrent laryngeal nerve
D. External laryngeal nerve
CHAPTER 21 ANSWERS
1. A. Pulmonary function test results have not been shown to be beneficial or to guide treatment when planning for intraoperative anesthesia. History and physical exam are the basics and important in anesthesia plan formulation. Baseline chest films along with arterial blood gas results are not indicated in every pulmonary patient, but may be helpful in anesthesia decision-making and intraoperative anesthetic management.
2. B. With the exception of emergency surgery, current guidelines suggest waiting at least for a 1-month time interval following a coronary intervention, before proceeding with any elective surgical procedure.
3. A. Generally speaking, the indications for cardiovascular investigations are the same in surgical patients as in any other patient. Unless the combined risk of coronary intervention and surgery is less than surgery alone without coronary intervention, preoperative CABG/stent, etc., is not generally suggested.
4. D. Indications for a lumbar sympathetic blockade include diagnosis, prognosis, and therapy of circulatory and pain conditions such as inoperable peripheral vascular disease, vasospastic disease (lower), reflexive sympathetic dystrophies and herpes zoster (lower), and the presence of pain (neuropathic, urogenic/pelvic, cancer pain, and phantom limb). Contraindications for a lumbar sympathetic blockade include anticoagulant therapy, hemorrhagic disorder, allergy to injected medications, infection, local neoplasm, and local vascular anomalies. Lumbar sympathetic chain includes L3–L5 ganglia, and is positioned anterior to L2, L3, and L4 vertebral bodies, anterior to the psoas muscle margin and fascia, posterior to the vena cava on the right, and posterior to the aorta on the left. Complications of a lumbar sympathetic blockade include blockade of the L2 somatic nerve root, injection into the subarachnoid/epidural/intravascular (vena cava/aorta/lumbar vessels) spaces, damage by needle or neurolytics to the kidneys/renal pelvis/ureters/intervertebral disks, infection, backache, neuropathic pain, hematoma, sympathalgia, destruction of sympathetic fibers (cramping/burning pain to anterior thigh), sympathectomy-mediated hypotension, intravascular steal (especially arteriosclerotic patient), and failure of ejaculation.
5. B. Airway blockade techniques: For anesthesia of nasal mucosa and nasopharynx, and nasal intubation, the sphenopalatine ganglion and ethmoid nerves need to be anesthetized. For anesthesia of the mouth (oropharynx and tongue base), the glossopharyngeal and superior laryngeal nerve blocks need to be performed. For anesthesia of the hypopharynx, larynx, and trachea, the recurrent laryngeal nerve needs to be blocked by performing a transtracheal block.
6. D. Complications of stellate ganglion block include hematoma formation (vascular injury to carotid artery, internal jugular vein), nerve injury (vagus, brachial plexus roots), pneumothorax, esophageal perforation, intravascular injection (carotid or vertebral artery, internal jugular vein), epidural or intrathecal injection, hoarseness of voice (recurrent laryngeal nerve), elevated hemidiaphragm (phrenic nerve), infection, and Horner syndrome (ptosis, anhidrosis, miosis).
7. D. 1 MET = consumption of 3.5 mL O2/min/kg of body weight. Typically, 1 MET = dressing or eating; 2 MET = walking downstairs or cooking; 4 MET = gardening; 5 MET = climbing one to two flights of stairs. A patient unable to achieve the level of 4 to 5 MET is at an increasing risk of perioperative complications, typically cardiopulmonary adverse reactions.
8. C. The patient is Rh O+; therefore, there exists no need for RhoGam immunoglobulin injection. OB consultation should be initiated with any pregnant patient, and the obstetrician should decide the need for appropriate perioperative monitoring (continuous monitoring versus pre- and postoperative monitoring) of the mother and the fetus based upon the stage of pregnancy.
9. B. An E-cylinder of oxygen at 1,000 psig is approximately half full, that is, it has about 330 L of oxygen. If being consumed at a rate of 2 L/min, it will be exhausted in about 3 hours.
10. D. Vomiting in patient who has undergone an intracranial procedure may indicate raised intracranial pressure. Therefore, the patient needs to be evaluated immediately, and the neurosurgeon needs to be notified.
11. D. Parkinsonism of Parkinson disease (called when no identifiable cause) is associated with a loss of dopaminergic activity and a reciprocal increase in cholinergic activity in the brain.
12. A. General anesthesia is most often used in patients with MS. Regarding muscle relaxants, the use of succinylcholine should be avoided, as demyelination and denervation may increase the risk of succinylcholine-induced hyperkalemia. Nondepolarizing neuromuscular blockers are safe to use, but patients of MS may have altered sensitivity and prolonged duration of action, which may necessitate postoperative ventilation. Therefore, nondepolarizing muscle relaxants should be administered in minimal doses. Regarding regional anesthesia, spinal and epidural anesthesia and peripheral nerve blocks have been successfully used in patients with MS. Although spinal anesthesia has been implicated in postoperative exacerbations of MS symptoms, the finding is not fully confirmed. Furthermore, intraoperatively the patient’s temperature should be closely monitored, as even slight increases in body temperature may cause a decline in neurologic function postoperatively.
13. D. ECT is performed under general anesthesia. The patient is preoxygenated, and general anesthesia is induced with a hypnotic (methohexital or propofol). Once the patient is asleep, succinylcholine is administered to relax the muscles. Seizures produced by ECT have been known to cause musculoskeletal injuries and joint dislocations. Therefore, succinylcholine is used to relax the muscle and prevent such injuries. Airway is maintained with mask ventilation.
14. A. Cardiovascular response following an ECT consists of an initial parasympathetic response followed by a sympathetic response. The parasympathetic response may lead to severe bradycardia in some. Glycopyrrolate administered pre-ECT may attenuate the parasympathetic response and also decrease secretions. The sympathetic response leads to tachycardia and hypertension, which may lead to deleterious effects in patients with coronary artery disease. The sympathetic discharge can be attenuated by using β-blockers (esmolol, metoprolol) or labetalol.
15. D. Nondepolarizing muscle relaxants inhibit neuronal transmission to the muscle by blocking the nicotinic acetylcholine receptors. They act as competitive antagonists to acetylcholine (Ach) and prevent the binding of Ach to the receptors.
16. B. Ipratropium (atrovent) is a bronchodilator and acts on the muscarinic acetylcholine receptors in the smooth muscles of the bronchi in the lung when inhaled. It is a derivative of atropine, but has a quaternary amine structure and thus it does not cross the blood-brain barrier to cause central effects. Although ipratropium is commonly combined with albuterol as a rescue agent for bronchospasm, it should not be used as a replacement for albuterol.
17. C. Neostigmine is a reversible acetylcholinesterase inhibitor, the enzyme that breaks down acetylcholine. This leads to more acetylcholine being available for neuromuscular transmission, which can now competitively displace the nondepolarizing muscle relaxant molecules to cause the return of neuromuscular activity. Since succinylcholine is broken down by a similar enzyme (pseudocholinesterase), neostigmine administration leads to the prolongation of duration of action of succinylcholine. It should be remembered that neostigmine, when given (unintended) without the prior administration of a nondepolarizing muscle relaxant, can directly act as a muscle relaxant when given in sufficient dose.
18. A. Renal excretion accounts for about 50% of excretion of neostigmine (about 75% of that of pyridostigmine and edrophonium). It is important to note that the presence of renal failure decreases the plasma clearance of not only neostigmine (and pyridostigmine, edrophonium) but also nondepolarizing muscle relaxants. Therefore, if neostigmine is administered in the usual dosage, and overdoses of muscle relaxants are avoided, renal failure should not be associated with recurarization.
19. A. Edrophonium is given in a dose of 0.5 to 1 mg/kg and has an onset of action in 30 to 60 seconds. Peak action occurs in 1 to 5 minutes and duration of action of is about 5 to 20 minutes. Because of its short duration of action, patients should be monitored for the effects of recurarization. Onset of neostigmine’s action (0.04–0.07 mg/kg) is in 1 to 3 minutes, peak effect occurs in 5 to 7 minutes, and duration of action is 40 to 60 minutes. Pyridostigmine is not used for neuromuscular reversal, and physostigmine has no role in neuromuscular blockade reversal.
20. C. Local anesthetics, when infiltrated into tissues, get absorbed into the circulation to some extent. The amount of local anesthetic absorbed into circulation depends upon the vascularity of the area. Highest blood concentration occurs with intercostal infiltration due to the high vascularity of the area.
21. B. Painless vaginal bleeding is most commonly due to placenta previa. A full-term parturient who presents with active painless vaginal bleeding should be taken to the operating room for cesarean section under general anesthesia. Examination with a vaginal speculum may initiate massive hemorrhage and hence should be not performed. Patients should have large-bore IVs (even a central line) for adequate fluid resuscitation, and blood should be available for transfusion. Patients with placenta previa, who are less than 37 weeks of gestation, and with mild bleeding, may be managed with bed rest and observation.
22. A. The most common cause of delayed emergence is residual anesthetics. These can be sedatives, analgesics, muscle relaxants, or volatile inhalational agents. Overdose of narcotics can be reversed by naloxone, benzodiazepines can be reversed by flumazenil, muscle relaxants are reversed with an appropriate dose of neostigmine–glycopyrrolate and administered as per the train-of-four twitch monitoring, and volatile agents are washed out by adequate ventilation. Hypoventilation can lead to hypoxia and hypercarbia. Hypothermia potentiates the effects of CNS depressants, and can be prevented by using forced-air-warming devices, using warm intravenous fluids, and raising the ambient room temperature. Other causes of delayed emergence include hypotension and metabolic abnormalities.
23. C. Once the administration of volatile agent is stopped at the end of the surgery, the washout or elimination occurs primarily through the lungs. Hence, adequate ventilation is the main route of elimination of volatile inhalational agents. Hypoventilation due to any cause will decrease the washout of volatile anesthetics and delay emergence from anesthesia.
24. A. Emergence from intravenous anesthetics depends primarily on redistribution from the brain. However, as the intravenous drugs accumulate, due to repeated administration or infusion, emergence becomes dependent on metabolism and elimination half-life. Presence of hepatic or renal disease, and the pharmacokinetics of the agents, also affects emergence from anesthesia.
25. A. Volatile inhalational agents cause peripheral vasodilation and cause redistribution of heat from the body core to the peripheral compartment. Using isoflurane in such a high concentration (2 MAC) is the most likely cause of shivering in the PACU in this patient. Other causes that can cause shivering are cold ambient operating room temperature, using unwarmed intravenous fluids, and an open large wound (exploratory laparotomy). Shivering tries to raise the body’s temperature by causing intense vasoconstriction. In addition, shivering can increase the oxygen demand tremendously, which can be of issue in patients with coronary artery disease. Shivering can be treated with meperidine (12.5–25 mg IV). Hypothermia should be treated by raising the room temperature or by using a forced-air-warming device.
26. D. One of the best methods to prevent hypothermia and shivering is using a forced-air-warming device intraoperatively or in the postanesthesia care unit. Meperidine is commonly used to treat shivering, 12.5 to 25 mg IV. Warming lights, raising the room temperature, and using warm intravenous fluids are other methods to prevent or treat hypothermia.
27. C. Patients undergoing radical neck dissection for laryngeal cancer often have a tracheostomy tube. After induction, the tracheostomy tube is commonly replaced with an ETT, which is sutured into place by the surgeon. The ETT should be placed carefully, and adequacy of ventilation should be checked by ausculating breath sounds and the presence of end-tidal CO2. A malposition of the ETT, including placement in a false passage will lead to high peak inspiratory pressures. Other causes listed can also lead to high inspiratory pressures.
28. A. LS is a forceful involuntary spasm of laryngeal muscles. It is due to stimulation of the superior laryngeal nerve. LS occurs commonly due to intense stimulation during light anesthesia (during extubation). Also, the presence of oral secretions can lead to LS. Treatment of LS is done by providing positive-pressure breaths (bag and mask) with 100% oxygen. This usually breaks the LS. However, if LS persists, succinylcholine is administered in a small dose (0.25 mg/kg) to relax the laryngeal muscles.
Side effects of inhaled ipratropium are minimal and include dry mouth, skin flushing, tachycardia, palpitations, and headache. It is contraindicated for use in patients with narrow angle–closure glaucoma. In patients with prostatic hypertrophy, it can lead to urinary retention, and hence should be used with caution in these patients.
Parkinsonism is characterized by progressive loss of motor function resulting from the degeneration of neurons in substantia nigra region of the brain. The onset of Parkinson disease typically occurs between the ages of 60 and 70 years. Clinical signs include a slight tremor of the thumb and forefinger (pill-rolling tremor), muscular rigidity (arms, legs, neck), bradykinesia (difficulty in initiating movement), postural instability, a shuffling gait, lack of facial expression (masked face), and difficulty in swallowing or speaking. The disease slowly progresses over 10 to 20 years, resulting in paralysis, dementia, and death.