21. Which of the following surgical conditions may negatively influence changes on
somatosensory-evoked potentials (SSEPs) wave forms?
B. Ischemia induced by hypoperfusion
1. C. Placement of bone cement (bone cement implantation syndrome) can result in
any combination of adverse events including hypoxia, hypotension, cardiac
arrhythmias (possibly heart block or even sinus arrest), pulmonary hypertension, and
2. A. Use of a compression tourniquet on upper and lower extremities can facilitate
surgery and decrease blood loss, but it can result in complications and cannot be
applied for prolonged periods. Use of such devices can be associated with ischemic
pain that is not typically or completely relieved by performing peripheral nerve
blocks of the extremity. Metabolic alterations upon tourniquet release, arterial
thromboembolism, and pulmonary embolism are other potential complications.
3. B. A venous fat embolism will typically present itself within 72 hours following
long-bone and/or pelvic fracture injuries. Such a condition may also occur following
cardiopulmonary resuscitation, parental feeding with lipid infusion, and liposuction
surgery. The classical triad includes dyspnea, confusion, and petechiae.
4. D. Advantages of neuraxial anesthesia in orthopedic surgery may include reduced
incidence of DVT and PE formation, decreased platelet activity, decreased factor
VIII and von Willebrand factor activity, and attenuation of stress hormone responses.
5. C. For patients receiving once-daily dosage of LMWH for prophylaxis, both
epidural and spinal neuraxial techniques may be performed (or neuraxial catheters
placed or removed) 10 to 12 hours following the previous dose of LMWH. In
addition, a 4-hour time delay should occur before administering the next dose of
6. D. Advanced RA can affect the cervical spine such that patients may require
treatment including steroids, immune therapy, and/or methotrexate. Radiographs of
both flexion and extension with lateral views of the cervical spine are necessary to
rule out atlantoaxial instability. If atlantoaxial instability is present, intubation should
be performed with inline stabilization utilizing video or fiberoptic laryngoscopy to
minimize excessive head and neck movement in order to reduce the incidence of
cervical spinal cord/nerve root injury.
7. D. Any form of muscle damage of sufficient severity can cause rhabdomyolysis.
Multiple causes can be present simultaneously in one individual. Some patients may
have an underlying muscle condition, usually hereditary in nature, which may make
them more prone to rhabdomyolysis. Rhabdomyolysis can be induced by several
conditions including compartment syndrome, prolonged tourniquet inflation time,
medications such as statins, and malignant hyperthermia. It is suggested that
tourniquet times usually be kept to 2 hours or less to decrease the risk of nerve
injury, ischemia, and rhabdomyolysis, which could lead to renal failure.
8. D. According to the American Society of Regional Anesthesia and Pain Medicine
anticoagulation guidelines, medications such as antiplatelet agents (Plavix, and
intravenous glycoprotein IIb/IIIa inhibitors), thrombolytics, fondaparinux, direct
thrombin inhibitors, or therapeutic LMWH present an unacceptable risk for spinal
and/or epidural hematoma development without sufficient time lapse between
administration of such medications and neuraxial techniques. Maximum
administration of subcutaneous heparin of 5,000 U bid is estimated to be safe with
epidural and spinal anesthesia. Heparin administration of 5,000 U tid is not known to
be accepted in clinical practice in conjunction with neuraxial blockade.
9. A. Blood loss in a patient secondary to a hip fracture can be significant, and some
anesthesiologists plan to utilize cell savers and/or perform hypotensive techniques to
minimize further blood loss. Blood loss from a hip fracture depends on the actual
location of the fracture. As a general rule, intracapsular (subcapital, transcervical)
fractures have been associated with less blood loss than extracapsular (base of the
femoral neck, intertrochanteric, subtrochanteric) fractures, as the capsule decreases
blood loss by acting like a tourniquet. In general, blood loss from a subtrochanteric
and intertrochanteric > base of femoral neck > transcervical and subcapital.
10. D. Intrathecal morphine can depress ventilation and CO2
last for up to 24 hours. The first peak effect occurs about 6 to 8 hours post injection,
and the second peak could happen as late as 24 hours later. The physiologic and
pharmacologic mechanisms of this include vascular opioid uptake by the epidural or
subarachnoid venous plexuses, rostral spread of the aqueous cerebrospinal fluid to
the brainstem, and/or direct perimedullary vascular channels.
11. D. Total hip arthroplasty surgery can be characterized by significant blood loss,
especially in the situation of bilateral hip replacement. In acute bleeding, measuring
an Hct may not accurately reflect the true value as equilibrium takes some time to
show the true Hct. In addition, bone cement can cause vasodilation, which can further
contribute to the low blood pressure. Cement placement has been associated with
pulmonary embolism and pulmonary hypertension.
12. D. Chronic pain is often a common occurrence in patients presented for spine/back
surgeries. A multimodal therapeutic pain management strategy aimed at different
pain cascade pathways is frequently utilized. It is a common practice to continue
methadone if patients are already taking such medications and to consider starting
methadone in patients with uncontrolled postoperative pain. Ketamine (GABA
agonist) is effective in chronic pain patients. TAP blockade with local anesthetics
can provide effective somatic pain relief of the anterior abdomen that will help in the
been associated with a rate of nonunion, so are therefore discouraged.
13. A. High concentrations of potent inhalational agents (such as desflurane and
sevoflurane) may increase neuromonitoring latency and decrease amplitude of the
SSEP and MEP. Therefore, inhalation agents can be used for intraoperative
maintenance anesthesia, but are used at less than one full MAC concentration.
Intravenous (IV) anesthetics are more commonly used for maintenance of anesthesia,
as they are more compatible with SSEP and MEP neuromonitoring (some expected,
but tolerable changes on either latency and/or amplitude). These IV anesthetics
include propofol, ketamine, etomidate, dexmedetomidine, benzodiazepines, and
opioids independently and in various combinations. Opioids have the least potential
to interfere SSEP and MEP neuromonitoring.
14. D. Spine surgery can be associated with significant blood loss. Surgical and
anesthetic techniques that have been developed to control perioperative blood loss
include hemodilution, autologous blood donation preoperatively, use of cell saver,
and epinephrine at wound site. Pharmacologically, antifibrinolytics such as
tranexamic acid and ε-aminocaproic acid have been used with some efficacy.
Tranexamic acid is a synthetic derivative of the amino acid lysine, and it is used to
treat or prevent excessive blood loss during surgery and in various other medical
conditions. Aprotinin has been associated with a 50% increase of cardiac side effects
(myocardial infarction/congestive heart failure), increase (double) of the risk of
stroke, and higher death rates (increased mortality).
15. C. Prone positioning of patients needs to be carefully executed, especially during
spine surgeries (prolonged procedures) and in patients who have other associated
comorbidities such as rheumatoid arthritis and ankylosing spondylitis. The
endotracheal tube needs to be properly secured, and eyes and nose should be padded
and checked periodically to ensure that they are pressure-free. The neck and arms
should be kept positioned in an anatomically neutral position. The abdomen needs to
remain free to avoid increased venous pressure (assists in reducing increased venous
bleeding) and to reduce the incidence of abdominal compartment syndrome that can
develop during prolonged duration of surgical intervention and aggressive fluid
16. D. Ischemic optic neuropathy is a major cause of perioperative POVL accordingly
to the vision loss registry collected by the ASA. Any increase of intraocular pressure
(IOP) or decrease on mean arterial pressure (MAP) will affect ocular perfusion
pressure (OPP), particularly with patients in a head-down position where edema can
develop in the orbit that will increase venous pressure. OPP = MAP − IOP. CRAO
accounts for a small percentage of patients who experience vision dysfunction
according to the vision loss registry. CRAO may be embolic in nature or the result of
direct pressure on the eyeball; therefore, it tends to be mostly unilateral.
17. D. Release of a tourniquet used on an extremity during surgery is often associated
with the release of metabolic (acidotic) by-products from the ischemic limb that are
dumped into the systemic circulation. In patients with poor preoperative functional
status or those that may experience significant intraoperative blood loss, the
increased systemic metabolic by-products may be enough to result in hypotension
and cardiac arrhythmia that may require volume resuscitation and/or pharmacologic
support. In rare instances, the hyperkalemia may need to be treated (sodium
18. D. During unilateral knee replacement surgery, properly functioning lumbar
epidural and femoral perineural catheters can provide equivalent perioperative
analgesia. However, a peripheral nerve block using a femoral perineural catheter
does not have several of the typical side effects that can be associated with neuraxial
blockade, such as more intense sympathectomy, pruritus (when opioids are mixed
with local anesthetics), nausea and vomiting, urinary retention, or orthostatic
hypotension and lightheadedness. Several studies have shown that patients with
regional anesthesia/analgesia (femoral catheter patients may meet discharge criterion
earlier) may show earlier improved outcomes. Considering variations of surgical
technique, the postoperative pain during total knee arthroplasty is located on the
anterior knee that can be equally controlled by either lumbar epidural or femoral
nerve block alone. For bilateral knee replacement surgery, either bilateral femoral
catheters or lumbar epidural catheter may be a reasonable option.
19. C. Shoulder operations may be performed in either a sitting (“beach chair”) or the
lateral decubitus position. The beach chair position may be associated with
decreases in cerebral perfusion leading to the potential for increased risk of
blindness, stroke, and brain ischemia. If a controlled hypotension technique is chosen,
an arterial transducer should be positioned most preferably at the level of the brain
stem (i.e., external meatus of the ear).
20. D. Most of the currently used anesthetic agents may have some effects/negative
influence on SSEP (differences may be minor or major changes). Several other
perioperative variables such as hemoglobin concentration, temperature, CO2
arterial blood pressure may also influence the SSEP tracing.
21. D. There are a host of reasons causing negative SSEP-tracing changes. In addition
to several anesthetic considerations (from anesthetic agent choice to techniques
used), there are surgical techniques and considerations that can influence SSEP.
Direct trauma, ischemia, and pressure to the spinal cord are capable of inducing
acute changes on SSEP. In addition, spinal cord ischemia changes secondary to
decreased blood supply, and/or vessel injury (stretching/pressure) may take as much
as a half an hour to manifest itself.
Deppu Ushakumari and Ashish Sinha
1. Which of the following is responsible for the plateau phase of cardiac action
A. Slow movement of potassium out of the cell
B. Slow movement of calcium into the cell
C. Slow movement of calcium out of the cell
2. A 2-year-old boy is induced with halothane-inhalation induction. The patient
suddenly gets bradycardic, and you decide to administer atropine 0.4 mg
intravenously. Immediately thereafter, you notice that the patient is having a
junctional tachycardia. Which of the following most accurately describes the
A. Sinoatrial (SA) node suppression by halothane followed by anticholinergic
B. Atrioventricular (AV) node suppression by halothane followed by
anticholinergic action of atropine
C. SA node and AV node suppression by halothane followed by anticholinergic
D. SA node and AV node suppression by halothane followed by paroxysmal
tachycardic action of atropine
3. Significant intravenous absorption/inadvertent intravenous injection of bupivacaine
can cause profound bradycardia and sinus node arrest. Which of the following best
describes the mechanism of cardiac toxicity of bupivacaine?
A. Bupivacaine binds inactivated fast sodium channels and dissociates from them
B. Bupivacaine binds activated fast sodium channels and dissociates from them
C. Bupivacaine binds inactivated slow sodium channels and dissociates from them
D. Bupivacaine binds activated slow sodium channels and dissociates from them
4. The mechanisms of depression of cardiac contractility by volatile anesthetics
include all the following, except
A. They decrease the entry of calcium into cells during depolarization
B. They affect only L-type calcium channels
C. They alter kinetics of calcium release
D. They decrease the sensitivity of contractile proteins to calcium
5. The mechanism of “x” descent (descent between C and V waves) in the following
right atrial tracing (Fig 11-1) is
A. Downward movement of the atrioventricular (AV) valve cusps after ventricular
B. Pulling down of the atrium by ventricular contraction
C. Relaxation of atrium after atrial systole
D. Decline in atrial pressure as the AV valves open
6. A 38-year-old healthy male volunteer is undergoing cardiac function tests as part of
a physiology experiment. His vital signs are HR = 62 bpm, BP = 124/74 mm Hg,
respiratory rate = 12 breaths/min, SpO2 = 100% on room air, and Hb = 14 g/dL.
Which of the following is the best determination of the adequacy of his cardiac
B. Cardiac output 8.1 L/min by thermodilution technique
C. Cardiac output 8.1 L/min by Fick method
D. SvO2 of 75% from a pulmonary artery (PA) catheter
7. Which of the following patients will be affected the most from loss of atrial
A. A 65-year-old patient with severe aortic regurgitation who went into recent
B. A 35-year-old patient with mitral-valve area of 1.0 cm2 who went into recent
C. An 80-year-old patient with severe aortic stenosis who went into recent onset
D. A 55-year-old patient with acute right-ventricular myocardial infarction
8. Which of the following formulae explains the hypertrophy of heart in response to
pressure or volume loads (P, intraventricular pressure; R, ventricular radius; t, wall
thickness; T, circumferential stress)?
9. Dose of heparin (U/kg) administered for cardiopulmonary bypass is (approximately)
10. The sinoatrial and the atrioventricular (AV) nodes are supplied in majority of the
A. Left anterior descending artery
D. Posterior descending artery
11. Baroreceptor reflex is ineffective for long-term blood pressure (BP) control because
A. Renin angiotensin aldosterone system takes over the control
B. Renal regulation of BP is more powerful
C. Of adaptation to changes in BP over 1 to 2 days
12. Which of the following portions of myocardium has a dual blood supply?
13. Which of the following types of myocardial work needs the highest oxygen
14. Which of the following inhalational agents causes the least coronary vasodilation?
15. Which of the following surgeries carries the highest cardiovascular risk?
C. Femoral–popliteal bypass surgery
16. A 67-year-old patient with uncontrolled hypertension presents for an elective
dialysis access creation. Which of the following techniques is not suited for
attenuating the hypertensive response to intubation?
A. Administering 3 μg/kg of fentanyl intravenously
B. Administering topical airway anesthesia
C. Administering lidocaine 0.5 mg/kg intravenously
D. Administering esmolol 1 mg/kg intravenously
17. The patient mentioned above develops severe hypotension immediately after
intubation. Which of the following agents is most suited to bring the blood pressure
18. Which of the following antianginal agents has the highest coronary vasodilating
19. Which of the following statements about calcium channel blockers (CCBs) is not
A. CCBs potentiate both depolarizing and nondepolarizing neuromuscular blockers
B. CCBs potentiate the circulatory effects of volatile anesthetic agents
C. Verapamil may decrease anesthetic requirements
D. Verapamil has no effect on cardiac contractility; it acts only on the
20. Which of the following β-blockers is most suited for a patient with bronchospastic
21. A 24-year-old female patient with a preoperative QTc interval of 550 ms is
undergoing breast surgery under general anesthesia. Droperidol is administered to the
patient for prevention of postoperative nausea, following which the patient goes into
polymorphic-ventricular tachycardia. Which of the following drugs/therapies is best
for the patient at this point?
22. Which of the following factors is not associated with severe multivessel disease
during exercise electrocardiography?
A. Sustained decrease (≥10 mm Hg) in systolic blood pressure during exercise
B. Failure to reach a maximum heart rate greater than 70% of predicted
C. Persistence of ST-segment depression after exercising for 5 minutes or longer
D. A 1-mm upsloping of ST segment
23. Surgical electrocautery may cause a problem with an automated implantable
cardioverter defibrillator (AICD) by all the following mechanisms, except
A. AICD interpreting a cautery current as ventricular fibrillation
B. Inhibition of pacemaker function due to cautery artifact
C. Increased pacing rate due to activation of a rate-responsive sensor
D. Cautery current generating too much heat at the location of AICD and causing
24. Which of the following ECG leads is most sensitive to detect an anterior-wall
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