Practice Exam II

Question 1

Which of the following respiratory parameters/responses is increased during volatile anesthesia?

• Ventilatory response to hypoxemia
• Respiratory frequency
• Ventilatory response to CO2
• Airway resistance

Answer 1

Respiratory frequency

Volatile inhaled anesthetics produce dose dependent and drug specific effects. Respiratory frequency is increased while ventilatory responses to CO2 and hypoxia are diminished and airway resistance is decreased.

Question 2

Supplying ungrounded power to the operating room requires the use of a:

• line isolation monitor
• ground fault circuit interrupter
• line isolation transformer
• case-to ground conductor

Answer 2

line isolation transformer

The line isolation transformer uses electromagnetic induction to induce a current in the ungrounded winding of the transformer. No direct electrical connection exists between the power supplied by the utility company and the power induced by the transformer and supplied to the operating room.

Question 3

The National Institute for Occupational Safety and Health (NIOSH) recommends that waste anesthetic gas exposure to volatile anesthetic agents not exceed:

Answer 3

2 ppm

NIOSH recommendations are: nitrous oxide

Question 4

A graph depicting the ventilatory responses to CO2 under different conditions is shown (Click here to display graph). By dragging & reordering the selections in yellow, match the condition with the associated graph trace.

A
B
C
D

Fentanyl
Asleep, Normal
Metabolic Acidosis
1 MAC Isoflurane

Answer 4

Metabolic Acidosis—>A
Asleep, Normal—>B
1 MAC Isoflurane—>C
Fentanyl, 10 mcg/kg—>D

Question 5

Respiratory alkalosis is always characterized by:

• PaO2 greater than 90 mmHg
• PaCO2 less than 35
• pH less than 7.40
• PaCO2 greater than 45

Answer 5

PaCO2 less than 35

Respiratory alkalosis results from an increased alveolar minute ventilation and is always associated with decreased PaCO2.

Question 6

The class of drug with the highest incidence of hypersensitivity is:

• propofol
• depolarizing muscle relaxants
• antibiotics
• protamine

Answer 6

antibiotics

Although rare, allergic reactions to antibiotics exceed any of the other agents used in the OR.

Question 7

After an episode of masseter muscle rigidity, the percentage of children that develop MH is approximately:

Answer 7

20%

Masseter muscle rigidity (MMR) has been associated with MH. MMR is most commonly seen in children between 8 and 12 years of age. In about 20% of cases, frank MH supervenes immediately after MMR.

Question 8

The most rapid reversal of neuromuscular blockade can be achieved with the use of:

• pyridostigmine
• physostigmine
• neostigmine
• edrophonium

Answer 8

edrophonium

Edrophonium is faster then neostigmine, which is faster than pyridostigmine

Question 9

Despite constituting only about 2% of total body weight, the percentage of cardiac output received by the brain is approximately:

Answer 9

15%

The high metabolic rate of the brain accounts for the disproportionately large blood flow. The overall metabolic rate for the brain in a young adult is about 3.5 ml O2 per minute per 100 gm of brain tissue.

Question 10

Fire in the respiratory circuit of the anesthesia machine has been reported when desiccated carbon dioxide absorber is used with:

• desflurane
• sevoflurane
• isoflurane
• nitrous oxide

Answer 10

sevoflurane

In 2003, Abbott laboratories advised of a situation where fire and/or extreme heat in the anesthesia circuit occurred with the use of sevoflurane and desiccated carbon dioxide absorbent. It should be noted that this event is different than the production of carbon monoxide from desiccated carbon dioxide absorbent, which is more common with the use of desflurane.

Question 11

Complications of positive pressure ventilation in a patient with a bronchopleural fistula include:

• air entrapment within the healthy lung
• tension pneumothorax
• hyperventilaton of the healthy lung
• decreased alveolar ventilation
• hypocarbia
• contamination of the healthy lung if empyema exist

Answer 11

tension pneumothorax, decreased alveolar ventilation, contamination of the healthy lung if empyema exists

Problems associated with the use of conventional positive pressure ventilation in patients with bronchopleural fistula (BPF) are largely the result of loss of alveolar ventilation to the fistula. This can result in tension pneumothorax and/or elevated CO2. In addition, if empyema also exists, positive pressure ventilation may spread the infection into the healthy lung. Air entrapment within the lung and hyperventilation are not associated with BPF and positive pressure ventilation.

Question 12

Approximately twenty-four hours after a laparoscopic-assisted vaginal hysterectomy, your patient exhibits left foot drop. The probable cause of this injury is due to damage of the:

• saphenous nerve
• common peroneal nerve
• femoral nerve
• obturator nerve

Answer 12

common peroneal nerve

The common peroneal nerve is the most frequently damaged nerve in the lower extremity. It is typically injured in lithotomy position when pressure is exerted laterally on the fibular head by the vertical bar of the stirrup. It manifests as foot drop, loss of dorsal extension of the toes, an inability to evert the foot, and sensory loss in the dorsal area of the foot.

Question 13

During cardiopulmonary bypass, carbon dioxide elimination is controlled by:

• the FiO2
• the direct contact of blood with the fresh gas
• the fresh gas flow
• the pump output

Answer 13

the fresh gas flow

Both the membrane and bubble oxygenators depend on the total fresh gas flow to determine carbon dioxide elimination. Oxygenation is determined by the FiO2.

Question 14

In the figure below, proper needle placement for a posterior approach to a popliteal fossa block is best represented by:
(Make your selection by clicking on the appropriate part of the figure)

Answer 14

For the posterior popliteal fossa block, the patient is positioned prone. With the knee slightly flexed, a triangle is delineated by the skin crease of the posterior fossa (base), the medial border of the triangle of the semimembranosus muscle and the lateral border of the biceps femoris muscle. In order to block the sciatic nerve before it separates into its 2 smaller components it is recommended that the point of the needle be inserted 7 - 10 cm above the skin crease.

Question 15

The single greatest risk factor for cardiac surgery is:

• history of congestive heart failure
• previous myocardial infarction
• aortic stenosis
• mitral regurgitation

Answer 15

history of congestive heart failure

Ejection fractions under 40% are associated with increased operative risk and a history of CHF is the single greatest risk factor for cardiac surgery.

Question 16

As a result of fresh gas coupling:

• tidal volume is less than indicated on the ventilator
• tidal volume is greater than indicated on the ventilator
• tidal volume is accurately reflected by the indicators on the ventilator
• minute ventilation is unaffected by changes in fresh gas flow

Answer 16

tidal volume is greater than indicated on the ventilator

Fresh gas coupling increases tidal volume as a result of the inflow of fresh gas from the machine during the inspiratory phase. Some newer machines have decoupling valves to compensate for the effects of fresh gas coupling.

Question 17

Insulin release is can occur in response to:(select 3)

• the direct effect of glucose
• presence of amino acids in the GI tract
• beta-adrenergic stimulation
• the administration of anticholinergic medication
• alpha-adrenergic stimulation

Answer 17

the direct effect of glucose, presence of amino acids in the GI tract, beta-adrenergic stimulation

Insulin release is related to a number of events: the direct effect of glucose and amino acids, vagal stimulation, beta-adrenergic stimulation and alpha-adrenergic blockade.

Question 18

A list of agents used in the treatment of asthma is shown below. By dragging & reordering the selections in yellow, match the agent with its mechanism of action.

Montleukast
Metaproterenol
Ipratropium
Theophylline

Anticholinergic
decrease Leukotrienes
decrease Phosphodiesterase
Beta stimulation

Answer 18

Decreased Leukotrienes—>Montleukast
Beta Stimulation—>Metaproterenol
Anticholinergic—>Ipratropium
Decreased Phosphodiesterase—>Theophylline

Question 19

In the circuit diagram of an isolation transformer shown below, electric shock can occur if: (select 2)

• the “Hot” line becomes grounded
• “Line 1” becomes grounded
• “Line 2” becomes grounded
• “Line 1” becomes grounded
• the patient becomes grounded
• the patient makes contact with “Line 2”

Answer 19

“Line 2” becomes grounded, the patient makes contact with “Line 2”

In order for electrical shock to occur, the patient must complete a circuit. In this case, the line isolation transformer has isolated the power from ground. However, if “Line 2” becomes grounded, or the patient makes physical contact with “Line 2”, the patient can now complete the circuit and receive a shock.

Question 20

Agents associated with the induction of the cytochrome P-450 system include:

• ketamine
• narcotics
• propofol
• cimetidine

Answer 20

ketamine

Ethanol, barbiturates, ketamine, and possibly benzodiazepines are capable of enzyme induction, increasing production of the hepatic enzymes that metabolize those drugs. Conversely, some agents such as cimetidine and chloramphenicol can prolong the effects of other drugs by inhibiting these enzymes.

Question 21

You are asked to evaluate a 16-year-old 68 kg male for correction of scoliosis. The patient’s past medical history is non-contributory. In addition to routine pre-operative testing, you would order:(select 2)

• PFT
• hepatic function testing
• renal function testing
• ekg
• electromyography
• plasma TSH and ACTH levels

Answer 21

pulmonary function testing, electrocardiography

The primary aim of preoperative evaluation of patients with scoliosis is to detect the presence and extent of cardiac or pulmonary compromise. Respiratory reserve is assessed by exercise tolerance, vital capacity, and arterial blood gases. Cardiac studies are performed as indicated to optimize preoperative cardiovascular status. A brief neurologic examination will document pre-existing neurologic deficits. Finally, cervical mobility and upper airway anatomy are assessed to discover any potential airway or positioning difficulties.

Question 22

When intubating a 10-year-old child, the estimated depth of the endotracheal tube is:

Answer 22

17 cm

A general rule of thumb for measurement of proper placement of the endotracheal tube to the teeth is:
12 + age/2 = ETT cm mark @ lip.

Question 23

You are asked to evaluate a 76-year-old 58 kg female for severe postoperative nausea and vomiting. The patient’s past medical is significant for Parkinson’s disease treated with L-dopa/carbidopa. The most appropriate medication for nausea control in this patient is:

• prochlorperazine(Compazine)
• scopolamine
• droperidol
• metoclopramide

Answer 23

scopolamine

Parkinson’s disease is a disease of the basal ganglia secondary to a reduction in dopaminergic neurons. Drugs that block dopamine receptors are contraindicated in Parkinsonian patients. Scopolamine has a centrally acting anticholinergic effect that has been shown to be effective in treating postoperative nausea as well as improving mobility in Parkinsonian patients.

Question 24

In the figure below, the internal carotid artery is depicted by:

Answer 24

picture

Question 25

During the evaluation a 84-year-old 58 kg female scheduled for a laparoscopic cholecystectomy, the rhythm strip below is obtained. This strip is indicative of:

Answer 25

ventricular pacing

This rhythm strip demonstrates ventricular pacing as evidenced by the pacer spike immediately preceding each ventricular complex. The absence of a second spike 100 to 200 msec prior to the ventricular pacer spike indicates that this is ventricular pacing only.

Question 26

Which of the following may facilitate baseline variability of the fetal heart rate?

• atropine
• a premature fetua
• magnesium sulfate
• a healthy, mature fetus

Answer 26

A healthy, mature fetus

The healthy, mature fetus normally displays a baseline beat-to-beat variability which may be minimal ( 25 BPM). Baseline variability has become an important indicator of fetal well-being and represents a normally functioning autonomic nervous system.

Question 27

Four hours after induction of a 48-year-old 84 kg male having a resection of a glioma, the capnogram below is noted. Possible explanations for this capnogram include:

• hypoventilation
• hyperventilation
• exhaustion of the carbon dioxide absorber
• incompetent inspiratory valve

Answer 27

exhaustion of the carbon dioxide absorber

This capnogram shows a Phase I or inspiratory baseline that is elevated. This indicates that rebreathing is taking place and can be the result of an incompetent expiratory valve, exhausted carbon dioxide absorber, or channeling through the carbon dioxide absorber.

Question 28

Which of the following cardiac anomalies is commonly associated with Trisomy 21?

• Pulmonic atresia
• Hypoplastic left heart syndrome
• Truncus arteriosus
• Endocardial cushion defect

Answer 28

Endocardial cushion defect

Congenital heart disease occurs in 40% of patients with Trisomy 21 (Down’s Syndrome). The most frequently occurring defects are those which involve the endocardial cushion (i.e. AV canal), and ventricular septal defect.

Question 29

Corresponding to the arterial waveform tracing below, the maximum flow through the left coronary artery occurs at point: 
A
B
C
D

Answer 29

D

Left coronary blood flow occurs almost entirely during diastole and is also pressure dependent. After closure of the aortic valve, represented by the dicrotic notch on the arterial waveform, diastolic pressure is the highest while left ventricular pressure is rapidly falling. This is the period of maximal left coronary blood flow.

Question 30

A 3-year-old patient is undergoing correction of strabismus. During manipulation of the extraocular muscles the patient develops profound bradycardia. Cranial nerves involved in the precipitation of the bradyarrhythmia include the: (Select 2)

• optic nerve
• vagus nerve
• oculomotor nerve
• trigeminal nerve
• abducens nerve
• trochlear nerve

Answer 30

trigeminal, vagus nerves

The oculocardiac reflex consists of trigeminal (V) afferent and vagal (X) efferent pathways. Because of this, it is frequently referred to as the five and dime reflex.

Question 31

A syndrome of hypotension, hyponatremia, hyperkalemia, and acidosis has been associated with:

• an ACTH secreting pituitary tumor
• a glucocorticoid secreting adrenal adenoma
• hypoadrenalism
• a mineralocorticoid secretin adrenal adenoma

Answer 31

hypoadrenalism

Decreased glucocorticoid and mineralocorticoid production are associated with hypotension, hyponatremia, hypoglycemia, hyperkalemia, metabolic acidosis, and volume depletion.

Question 32

During CVP insertion, ultrasound guidance is being used. Using the figure below, indicate the most appropriate site of CVP introducer placement.

Answer 32

The red X above indicates the internal jugular vein. Its position relative to the carotid is more lateral and superficial.

Question 33

Block of the median nerve is accomplished by placing the needle adjacent to the:(Select 2)

• flexor carpi ulnaris tendon
• extensor pollicus longus tendon
• flexor carpi radialis tendon
• pisometacarpal ligament
• flexor retinaculum
• palmaris longus tendon

Answer 33

flexor carpi radialis tendon, palmaris longus tendon

Median nerve block is accomplished by placing the needle between the flexor carpi radialis and palmaris longus tendons at the level of the proximal crease of the volor aspect of the wrist.

Question 34

The correct unique pin arrangement for the nitrous oxide E cylinder shown below is position 5 (shown) and:
(Make your selection by clicking on the appropriate part of the figure)

Answer 34

In the pin index safety system (PISS), each cylinder valve has a unique arrangement of pins that corresponds to the intended cylinder contents. The pin arrangement matches holes in the yoke, which is the point that cylinders are attached to the gas machine. Pin configurations are: Oxygen - 2,5; Nitrous Oxide - 3,5; Air - 1,5. The PISS is another means of preventing misconnections.

Question 35

Advantages of leukodepleted blood products in transfusion therapy include a reduction in: (Select 3)

• alloimmunization
• CMV transmission
• HIV transmission
• febrile reactions
• postoperative bleeding
• hepatitis C transmission

Answer 35

alloimmunization, CMV transmission, febrile reactions

Confirmed benefits of leukoreduction include decreased alloimmunization, prevention of febrile reactions, reduced CMV transmission and reduced inflammatory mediator accumulation during blood storage.

Question 36

A list of waves & pressure changes seen in a normal central venous pressure tracing is shown below. By dragging & reordering the selections in yellow, match the waves with their corresponding cardiac event.

a-wave
y-wave
v-wave
c-wave

Atrial filling
Ventricular contraction
Atrial contraction
Tricuspid Opening

Answer 36

c-wave—>Ventricular Contraction
a-wave—>Atrial Contraction
v-wave—>Atrial Filling
y-descent—>Tricuspid Opening

The shape of the CVP waveform corresponds to the events of the cardiac cycle. A-waves result from atrial contraction, c-waves result from tricuspid displacement during ventricular contraction, v-waves result from atrial filling against a closed mitral valve, y-descent occurs upon opening of the tricuspid valve, and the x-descent occurs with ventricular relaxation.

Question 37

Drugs shown to increase both gastric pH and volume include:

• non-particulate antacids
• proton pump inhibitors
• metoclopramide
• H2 receptor blockers

Answer 37

non-particulate antacids

Although the most rapid increase in gastric pH can be achieved with non-particulate antacids such as 0.3M sodium citrate (Bicitra), these antacids also cause an increase in gastric volume. Gastric volume is decreased and pH is increased with H2 blockers. Proton pump inhibitors also increase pH, but have little effect on gastric volume. Finally, metoclopramide can reduce gastric volume, but has little effect on pH.

Question 38

When using the conventional pulse oximeter, falsely elevated levels of saturation may be seen with the presence of:

• carboxyhemoglobin
• reduced hemoglobin
• methemoglobin
• methylene blue

Answer 38

carboxyhemoglobin

Because the conventional pulse oximeter measures light absorbance at two wavelengths, it can deal with unknown concentrations of only two solutes: oxyhemoglobin and reduced hemoglobin. The conventional pulse oximeter interprets carboxyhemoglobin as though it were composed mostly of oxyhemoglobin and produces falsely high levels of saturation.

Question 39

The oxygen failure cutoff valve:

• monitors nitrous oxide and oxygen line pressure
• ensures supply pressure to the oxygen flowmeter
• ensures the flow of oxygen from the oxygen flowmeter
• ensures oxygen is present in the oxygen pipeline and/or oxygen tanks

Answer 39

ensures supply pressure to the oxygen flowmeter

The oxygen failure cutoff valve, formerly known as the fail-safe valve, ensures only that pressure is supplied to the oxygen flowmeter. It does not ensure adequate flow and does not ensure that a hypoxic mixture is not being used.

Question 40

Vital capacity in the anesthetized patient is reduced to the greatest degree in which of the following positions?

• supine
• reverse trendelenberg
• prone
• head down lithotomy

Answer 40

Head-down lithotomy

Lithotomy position reduces VC in the anesthetized patient by approximately 18%. Reverse Trendelenburg, supine, and prone positions all reduce VC by approximately 9.0, 9.5, and 10% respectively.

Question 41

A 50-year-old male presents for resection of a sigmoid carcinoma. His past medical history is significant for hypertrophic cardiomyopathy treated with metoprolol. After induction and intubation the blood pressure is noted at 76/48 mmHg. The most appropriate vasoactive therapy is:

• phenylephrine- 100 mcg IV
• ephedrine-10 mg IV
• dopamine-7 mcg/kg/min IV infusion
• epinephrine-0.04 mcg/kg/min

Answer 41

phenylephrine - 100 micrograms IV

Management of this patient’s hypotension should be directed at minimizing left ventricular outflow obstruction. Medications with beta-adrenergic effect are contraindicated. Phenylephrine will increase both preload and afterload without increasing myocardial contractility.

Question 42

The inhaled anesthetic agent causing the greatest decrease in cardiac output is:

• sevoflurane
• isoflurane
• desflurane
• nitrous oxide

Answer 42

sevoflurane

Sevoflurane mildly depresses myocardial contractility and cardiac output. Desflurane causes minimal to no depression in cardiac output and nitrous oxide and isoflurane are not associated with any depression in cardiac output.

Question 43

Phase II drug biotransformation reactions include:

• oxidation
• hydroxylation
• conjugation
• reduction

Answer 43

conjugation

Drug biotransformation reactions are divided into two groups: Phase I and Phase II. Phase I reactions alter the molecular structure of the drug by modifying an existing functional group, adding a new functional group or splitting the drug molecule. These reactions are hydrolysis, oxidation, or reduction. Phase II reactions consist of coupling or conjugation of compounds to polar chemical groups.

Question 44

Which stage of labor is characterized by rapid changes in cervical dilation?

• Stage I-latent phase
• Stage I-active phase
• Stage II
• Stage III

Answer 44

Stage I - active phase

The first stage of labor begins with the onset of regular contractions and concludes when the cervix is fully dilated. It is divided into two phases: the latent phase where there is cervical effacement but little dilation, and the active phase which is characterized by rapid changes in cervical dilation.

Question 45

A 62-year-old male is admitted after an automobile accident and is scheduled for an exploratory laparoscopy. Initial laboratory evaluation is found to be within normal limits except for an ethanol level of 175 mg/dl. From this information, the expected MAC of sevoflurane would be:

• increased from long-term ethanol exposure
• decreased from ethanol intoxication
• unchanged if the patient has a history of ethanol abuse
• unchanged if the patient has no history of ethanol abuse

Answer 45

decreased from ethanol intoxication

This patient has a significantly elevated ethanol level and will experience a decrease in MAC as a result of acute intoxication.

Question 46

A patient with a history of atrial fibrillation is evaluated preoperatively. Laboratory values include an INR of 2.1. Changes in coagulation in this patient are the result of impaired formation of:

• factors II, VI, IX
• von Willebrand co-factor
• prothrombin and factors V, VII, IX
• prothrombin and factors VII, IX, X

Answer 46

prothrombin and factors VII, IX, X

Vitamin K dependent factors are prothrombin and factors VII, IX, and X. Deficiency of vitamin K, or warfarin administration, results in a coagulopathy due to impaired formation of these factors and is easily treated with vitamin K replacement.

Question 47

During the administration of a general anesthetic with controlled ventilation the following arterial blood gas analysis is obtained:
pH - 7.29, PaO2 - 157 mmHg, PaCO2 - 52 mmHg, HCO3- - 25 mEq/L.
This blood gas is indicative of:

• uncompensated respiratory acidosis
• uncompensated metabolic acidosis
• compensated respiratory acidosis
• compensated metabolic acidosis

Answer 47

uncompensated respiratory acidosis

This patient has a low pH, elevated CO2 and a normal bicarbonate indicating uncompensated respiratory acidosis.

Question 48

Which physiologic derangement is most associated with the anhepatic phase of orthotopic liver transplantation?

• Hypocalcemia
• Hyponatremia
• Metabolic alkalosis
• Venous air embolism

Answer 48

Hypocalcemia

During the anhepatic phase of OLT, the liver is removed from the body. The citrate load from large transfusion of blood products is no longer metabolized and results in an acquired hypocalcemia.

Question 49

You are asked to evaluate a 27-year-old male in the PACU after receiving a general inhalation anesthetic for the repair of a ruptured biceps tendon. The patient’s cardiac rhythm is shown below. Your interpretation of this rhythm is:

• atrial fibrillation
• ventricular tachycardia
• atrial flutter with block
• sinus tachycardia

Answer 49

sinus tachycardia

This is a regular rhythm at about 140/min with each QRS complex preceded by a single P-wave.

Question 50

After the placement of a double-lumen tube for a left pneumonectomy, diffuse wheezing is detected in both lung fields. During this episode, the major site of resistance to airway flow in the bronchial tree is at the:

• trachea
• large bronchi
• medium-sized bronchi
• small airways

Answer 50

medium-sized bronchi

Increased small airway resistance remains the most common and most important cause of respiratory failure.

Question 51

During the preoperative assessment of a patient scheduled for a laparoscopic cholecystectomy, the thyromental distance is found to be 7 cm. From this information it is expected that:

• endotracheal intubation will be difficult
• the patient has a congenital abnormality of the airway
• normal endotracheal intubating conditions are present
• hypothyroidism is likely

Answer 51

normal endotracheal intubating conditions are present

The thyromental distance has been found to correlate to intubating conditions. A thyromental distance of less than 4.0 cm is predictive of difficult intubation conditions when used in combination with the Mallampati classification.

Question 52

The risk of aspiration is reduced by the reflex closure of the laryngeal inlet. The muscle(s) responsible for this closure include:
(Make your selection by clicking on the appropriate part of the figure)

Answer 52

The muscles controlling laryngeal movement are conveniently thought of as pairs having opposing actions. The laryngeal inlet in closed by the aryepiglottic muscle and opened by the thyroepiglottic muscle. The aryepiglottic muscle is innervated by the recurrent (inferior) laryngeal nerve.

Question 53

ECG changes associated with hypothermia include:

• the presence of J-waves
• shortened PR interval
• shortened QRS interval
• shortened QT interval

Answer 53

presence of J-waves

Severe hypothermia interferes with cardiac rhythm and impulse conduction. This results in the lengthening of the PR, QRS, and QT intervals, and the generation of J-waves.

Question 54

During the delivery of a general anesthetic to a 6-year-old patient undergoing a procedure in the radiology suite, you are delivering 3 L/min of nitrous oxide and 2 L/min of oxygen through a Mapleson D circuit. You have prepared for the case with fresh E cylinders of both oxygen and nitrous oxide. At the end of 3 hours of anesthetic administration, you would estimate the pressure in the nitrous oxide E cylinder to be:

Answer 54

745 psig

Nitrous oxide is stored as a liquid in the E cylinder. Therefore, the cylinder pressure of 745 psig represents the vapor pressure of liquid nitrous oxide at room temperature. The nitrous oxide pressure gauge remains at 745 psig until the liquid is gone. This occurs only after over 3/4ths of the tank has been consumed. Since a full nitrous oxide tank contains approximately 1590 L, there is no expected change in the tank pressure after the administration of the described anesthetic.

Question 55

At high flow rates, the nitrous oxide flowmeter could also be used to measure the flow of:

• oxygen
• carbon dioxide
• air
• helium

Answer 55

carbon dioxide

At high flow rates, when turbulent flow prevails, gases with similar densities can be interchanged without causing inaccuracy of the flowmeter. Carbon dioxide and nitrous oxide have molecular weights of 44 and similar densities.
At low flow rates, viscosity is the major determinant of the position of the bobbin. Helium and oxygen have similar viscosities and can be interchanged without affecting the reading of the flow meter at low flow rates.

Question 56

Bariatric procedures resulting in weight loss largely from decreased absorption, with minimal restriction, include: (Select 2)

• verticle banded gastroplasty
• sleeve gastrectomy
• roux-en-Y gastric bypass
• biliopancreatic diversion
• gastric banding
• duodenal switch

Answer 56

biliopancreatic diversion, duodenal switch

The mechanism of weight loss from bariatric surgery varies from the restriction of food intake (gastric banding, sleeve gastrectomy) to decreased absorption of food (biliopancreatic diversion, duodenal switch). The roux-en-Y procedure offers both restriction and decreased absorption.

Question 57

Over 70% or transurethral resections of the prostate are done under spinal anesthesia. The level of spinal anesthesia required is:

• T4
• T8
• T10
• S4

Answer 57

T10

Although the prostate gland itself receives sensory innervation from the S3 - S4 dermatomes, the bladder distension that occurs during a TURP mandates a T10 level.

Question 58

A 27-year-old-male arrives to the OR for resection of a mediastinal tumor. He has been treated with bleomycin within the last 6 months. Which of the following agents must be used with caution in this patient?

• Nitrous oxide
• Desflurane
• Sodium nitroprusside
• Oxygen

Answer 58

Oxygen

The most serious side effect of bleomycin, a cytotoxic agent, is pulmonary toxicity. It produces pulmonary endothelial capillary damage which progresses to alveolar epithelial injury of Type I cells and proliferation of Type II cells. It is speculated that injury results from acutely increased inhaled concentrations of O2 which facilitate production of superoxide and other free radicals. It has been recommended that inhaled O2 concentrations do not exceed 30%, or that O2 administration should be based on the patients minimum requirement to maintain an adequate O2 saturation.

Question 59

Early manifestations of transurethral resection syndrome include:

• hypotension
• hypernatremia
• tachycardia
• increased central venous pressure
• decreased pulse pressure
• increased pulmonary artery pressure

Answer 59

increased central venous pressure, increased pulmonary artery pressure

Cardiovascular manifestations of TURP syndrome are the result of acute volume overload. Bradycardia, hypertension, and increases in PAD, PCWP, increased pulse pressure and CVP are most commonly found.

Question 60

According to ACLS protocols, after initial assessment of ABCs, the definitive treatment for the rhythm depicted by the ECG strip below is:

• immediate defibrillation
• amiodarone 300 mg IV over 10 minutes
• lidocaine 1.5 mg/kg IVP
• precordial thump

Answer 60

immediate defibrillation

According to ACLS protocols, after assessment of the ABCs (airway, breathing, circulation) the appropriate initial treatment for VF/pulseless VT is immediate defibrillation.

Question 61

Isobaric solutions of local anesthetics for spinal anesthesia include:

• procaine 10% in water
• tetracaine 0.5% in NS
• bupivacaine 0.3% in water
• bupivacaine 0.75% in NS
• lidocaine 0.5% in water

Answer 61

tetracaine 0.5% in normal saline, bupivacaine 0.75% in normal saline

Hyperbaric Solutions tetracaine 0.5% in 5% dextrose
bupivacaine 0.75% in 8.25% dextrose
lidocaine 5% in 7.5% dextrose
procaine 10% in water

Isobaric Solutions tetracaine 0.5% in normal saline
bupivacaine 0.75% in normal saline
bupivacaine 0.5% in normal saline
lidocaine 2% in normal saline

Hypobaric Solutions tetracaine 0.2% in water
bupivacaine 0.3% in water
lidocaine 0.5% in water

Question 62

During recipient renal transplantation, markedly prolonged neuromuscular blockade should be expected with the use of:

• pancuronium
• succinylcholine
• cis-atracurium
• vecuronium

Answer 62

Pancuronium

Pancuronium is largely excreted in the urine (>90% renal excretion). Its elimination half-life is prolonged by more than 95% in patients with ESRD, particularly after repeated doses.

Question 63

You are asked to evaluate a 42-year-old female in the post-anesthesia care unit after a thyroidectomy. The patient is complaining of hoarseness with no shortness of breath. Indirect laryngoscopy reveals an immobile left vocal cord. The most likely cause of the hoarseness is:

• bilateral recurrent laryngeal nerve injury
• unilateral recurrent laryngeal nerve injury
• laryngeal hematoma
• tracheomalacia

Answer 63

unilateral recurrent laryngeal nerve injury

Complications after thyroidectomy include recurrent laryngeal nerve damage, tracheal compression from hematoma, tracheomalacia and hypoparathyroidism. Bilateral recurrent laryngeal nerve injury is very rare, but unilateral laryngeal nerve injury is more common, usually transient, and results in hoarseness.

Question 64

Decreases in maternal FRC:

• occur early in the first trimester of the pregnancy
• are responsible for a slower inhalation induction time
• are caused by increased levels of maternal progesterone
• are responsible for a more rapid desaturation seen with anesthesia

Answer 64

are responsible for a more rapid desaturation seen with the induction of anesthesia

The combination of increased oxygen consumption (33%) and decreased FRC (20%) increases the rate at which changes in alveolar concentrations of oxygen occurs.

Question 65

During the resection of a glioblastoma, the neurosurgeon requests hyperventilation to reduce the intracranial pressure. Maximal reduction of intracranial pressure with minimal risk of cerebral ischemia can be achieved at a PaCO2 of:

Answer 65

30 - 35 mmHg

PaCO2 reduction to 30 mmHg is the suggested target. Further hyperventilation risks cerebral ischemia especially in areas of pathology.

Question 66

Use of succinylcholine in infants:

• is absolutely contraindicated
• necessitates a larger IV dose due to rapid redistribution into the ECF
• is ineffective after an IM dose
• is associated with the development of tachydysrhythmias

Answer 66

necessitates a larger IV dose due to rapid redistribution into the ECF

Succinylcholine is highly water soluble and rapidly redistributes into the extracellular fluid volume. Since total body water content is increased in the neonate, the dose required for IV administration of succinylcholine is approximately twice that for older patients.

Question 67

You are asked to evaluate a 27-year-old man scheduled for incision and drainage of a submental abscess. Your examination reveals a well-nourished male, drooling with swelling and induration of the submental area. He is able to open his mouth to an aperture of 2 cms. He has not had any food or fluid intake in the last 36 hours as a result of recent dental extractions and oral pain. The safest method of induction of anesthesia and airway management is:

• slow inhalation induction with oxygen and sevoflurane
• rapid sequence induction
• intravenous induction without muscle relaxation
• preliminary tracheostomy under local anesthesia

Answer 67

preliminary tracheostomy under local anesthesia

This patient has Ludwig’s angina, a septic cellulitis of the submandibular region. Because of the possibility of airway compromise and limited ability to open the mouth, the safest course is to secure the airway with an awake tracheostomy.

Question 68

Flowmeters are:

• calibrated for 1 atmosphere of pressure at room temperature
• calibrated for the mean atmospheric pressure in the region they are to be used
• more accurate at flow rates less than 1 l/min

Answer 68

calibrated for 1 atmosphere of pressure at room temperature

Flowmeters are calibrated at atmospheric pressure (760 torr) and room temperature (20o C). Pressure changes will affect the gas viscosity and density and influence the indicated flow rate accuracy. Variations in temperature, as a rule, do not produce significant changes. Flowmeters are most accurate in the middle half of the tube.

Question 69

Preoperative pulmonary function testing of a 30-year-old female reveals the following:
FVC - 2.3 liters, FEV1 - 1.9 liters, FEV1/FVC - 0.85
These results indicate:

• restrictive lung disease
• chronic obstructive lung disease
• acute bronchospasm
• normal lung function

Answer 69

restrictive lung disease

This patient is demonstrating proportional reduction in lung volumes (decreased FVC and FEV1) without evidence of airway obstruction (normal FEV1/FVC).

Question 70

The saturated vapor pressure of isoflurane at 20o C is approximately:
(Enter numerical answer in box below. Click ‘Next’ when completed.)

Answer 70

238 mmHg

The vapor pressure of isoflurane is 238 mm Hg at 20o C.

Question 71

The primary treatment of complex regional pain syndrome type I (CRPS-1) of the upper extremity includes:

• opioid analgesics
• stellate ganglion blocks
• interscalene blocks
• physical therapy
• gabapentin administration
• cervical epidural blocks
• low-dose ketamine infusion

Answer 71

stellate ganglion blocks, physical therapy, gabapentin administration, low-dose ketamine infusion

The primary treatment for CRPS includes sympathetic blocks, physical therapy, and oral medications. Intravenous regional anesthesia with bretylium and lidocaine or ketorolac may also be employed. Pharmacologic therapy for CRPS includes gabapentin and memantine, an NMDA-blocker. If the patient does not respond to these treatments, spinal cord stimulation can be entertained.

Question 72

The threshold for smelling volatile anesthetic agent is approximately:

• 1-4 ppm
• 5-300 ppm
• 500-2500 ppm
• greater than 5000 ppm

Answer 72

5 - 300 ppm

The threshold for smelling volatile anesthetic is variously reported as 5 - 300 ppm. Therefore if any agent is smelled, the concentration is excessive and well above the OSHA standard.

Question 73

A 64-year-old patient is scheduled for laparoscopic cholecystectomy. The past medical history is significant for hypertension treated with lisinopril. Induction of anesthesia in this patient may be associated with:

• intraoperative hypotension
• increased stress hormone production
• exaggerated sympathetic response to surgical stimulation
• intraoperative bronchospasm

Answer 73

intraoperative hypotension

Hemodynamic instability and hypotension (vasoplegic syndrome) may occur during anesthesia in patients receiving ACE inhibitors or angiotensin II-receptor antagonists. Vasoplegic episodes are characteristically refractory to treatment with adrenergic vasopressors.

Question 74

A 75-year-old 80 kg male is scheduled for a radical prostatectomy. His preoperative hematocrit is 38%. The estimated blood loss required to reduce his hematocrit to 30% is approximately:

Answer 74

1318 mL

An adult has approximately 70 mL/kg total blood volume. Therefore:
80 kg x 70 ml/kg = 5600 mL (blood volume)
MABL = Blood Volume x (HCT(starting) - HCT(final)) / HCT(average)
5600 ml x (38 - 30) / 34 = 1318 mL

Question 75

The volume of vapor produced by one milliliter of sevoflurane liquid (specific gravity = 1.5 gm/ml, molecular weight = 180 gm) when vaporized is approximately:

Answer 75

180 - 220 mL of vapor

One ml of sevoflurane is 1.5 gms and 1.5/180 moles, or 0.0083 moles. Avogadro’s Law states that the volume of 0.0083 moles at STP is 0.0083 x 22.4 L/mole or 186 mL. Using Charles Law to adjust to a temperature of 20o centigrade (293o K): 186/273 = V/293; V = 200 mL.

Question 76

A 42-week-gestation neonate is delivered via emergency Cesearean section for persistent late decelerations and meconium stained amniotic fluid. At 1 minute post delivery, his color is cyanotic, and he grimaces and flexes his extremities slightly to stimulation. His heart rate is 110 BPM and respirations are 12/min and irregular. His corresponding Apgar score is:

Answer 76

5

Apgar Score 0 1 2
Heart Rate absent 100
Respiratory Effort absent slow, irregular good, crying
Muscle Tone flaccid some flexion active motion
Reflex Irritability none grimace crying
Color blue, pale body pink,
extremities blue all pink

Question 77

The ECG strip below is suggestive of:(strip has u waves)

• ischemia
• hypocalcemia
• hypokalemia
• hyponatremia

Answer 77

hypokalemia

This ECG strip has U waves present suggestive of hypokalemia

Question 78

A patient with a history of hepatic insufficiency is undergoing a revision of an arterio-venous fistula under regional anesthesia with a field block. Which of the following local anesthetics would be most appropriate for use in the patient?

• Procaine
• Prilocaine
• Bupivacaine
• LIdocaine

Answer 78

Procaine

Procaine, an ester local anesthetic, is predominately metabolized via hydrolysis by plasma cholinesterase. Amide local anesthetics such as prilocaine, bupivacaine, and lidocaine are metabolized by microsomal P-450 enzymes in the liver. Decreases in hepatic function will reduce the rate of metabolism of these drugs and predispose patients to systemic toxicity.

Question 79

As compared to retrobulbar blockade, periorbital blockade has the advantages of:

• decreased incidence of ecchymosis
• more rapid onset
• decreased risk of globe penetration
• reduced anesthetic volume needed

Answer 79

decreased risk of globe penetration

With peribulbar or periorbital blockade, the needle does not penetrate the cone formed by the extraocular muscles. This results in less risk of globe penetration, optic nerve and artery injury, and less pain on injection. Disadvantages include slower onset, larger anesthetic volume and an increased likelihood of ecchymosis.

Question 80

Post dural puncture headache (PDPH):

• occurs more frequently with the use of pencil point needles
• may result in diplopia from traction on cranial nerve VI
• should be immediately traded with an epidural blood patch
• is most likely to occur in elderly females

Answer 80

may result in diplopia from traction on cranial nerve VI

PDPH is believed to result from leakage of CSF from a dural defect and decreased ICP. Loss of CSF causes traction on structures supporting the brain, i.e. the dura and tentorium, and on cranial nerves. Diplopia may occur from traction on the sixth cranial nerve. PDPH is more likely to occur with the use of cutting point needles. Young age, female sex, and pregnancy are predisposing factors. Although epidural blood patch is an effective treatment modality, it does not reliably work immediately; effects may not be apparent for several hours.

Question 81

The most common permanent airway injury associated with endotracheal intubation is:

• temporomandibular joint pain
• dental damage
• arytenoid dislocation
• pharyngoesophageal perforation

Answer 81

dental damage

The most common permanent airway injury is dental damage and occurs in 1 in 4500 surgical cases. Sore throat and dysphagia are the most common temporary airway injuries.

Question 82

Which of the following induction techniques is most appropriate for the child with epiglottitis?

• Ketamine 2 mg/kg IM
• Propofol 2.5 mg/kg IV
• Quiet inhalation induction in the sitting position
• Quit inhalation induction in the supine position

Answer 82

Quiet inhalation induction in the sitting position

In the child with epiglottitis, any procedure which causes the child to cry will potentially interfere with breathing and may risk loss of the airway. In addition, placing the child in the supine position may precipitate complete airway obstruction. A quiet inhalation induction with the patient in the sitting position is the least invasive, therefore the most appropriate for this patient.

Question 83

Adequate ventilation through a cricothyrotomy with a 14 gauge intravenous catheter requires:

• continous positive pressure through a semi closed circuit
• continous positive pressure through a non-rebreathing circuit
• 100% oxygen at 50 psi
• a self inflating resuscitation bag

Answer 83

100% oxygen at 50 psi

The small lumen of an IV catheter mandates the use of a driving pressure of 50 psi to generate sufficient gas flow. Connection to an anesthesia circuit does not deliver adequate oxygen flow because of the high compliance of the circuit.

Question 84

The QT interval is defined as the distance from:

• the end of the P wave to the end of the T wave
• the beginning of the QRS complex to the beginning of the T wave
• the end of the QRS complex to the beginning of the T wave
• the beginning of the QRS complex to the end of the T wave

Answer 84

the beginning of the QRS complex to the end of the T wave

The QT interval varies with the heart rate, but normally is less than one-half of the preceding RR interval. Prolonged QT intervals have been associated with ventricular arrhythmias.

Question 85

A list of anticholinesterase agents is shown below. By dragging & reordering the selections in yellow, match the agent with its corresponding pharmacologic profile.

Tertiary Amine
Slow Onset
Competitive Inhibitor
Low Therapeutic Index

Edrophonium
Neostigmine
Physostigmine
Physostigmine
Pyridostigmine

Answer 85

Competitive Inhibitor—>Edrophonium
LowTherapeutic Index—>Neostigmine
Tertiary Amine—>Physostigmine
Slow Onset—>Pyridostigmine

Question 86

An 85-year-old female arrives to the OR for an ORIF of a left hip fracture. Her history is remarkable for hypertension and glaucoma. Her medications include enalapril, hydrochlorothiazide, metoprolol, and echothiophate drops. Which of the following medications should be used with caution in this patient?

• Glycopyrrolate
• Phenylephrine
• Succinylcholine
• Midazolam

Answer 86

Succinylcholine

Echothiophate is an irreversible cholinesterase inhibitor used in the treatment of glaucoma. Topical application of these drops leads to systemic absorption via the nasolacrimal ducts and conjunctival vessels, thereby reducing plasma cholinesterase activity. Since succinylcholine is metabolized by this enzyme, echothiophate will prolong its duration of action.

Question 87

Interpleural local anesthetic injection can provide analgesia to:

• the ipsilateral arm
• the chest wall
• the lower abdomen
• mediastinal structures

Answer 87

the chest wall

Interpleural analgesia can provide analgesia over the chest wall and upper abdomen through block of multiple intercostal segments.

Question 88

Mannitol causes a diuresis from:

• inhibition of sodium reabsorption in the proximal tubules
• competitively inhibiting aldosterone in the distal tubules
• creation of an osmotic gradient in the tubules
• inhibition of the chloride pump in the loop of Henle

Answer 88

creation of an osmotic gradient in tubules

Mannitol is considered an osmotic diuretic. It is filtered at the glomerulus but not reabsorbed. Mannitol’s hyperosmolality reduces interstitial water increasing its excretion. Mannitol also acts as a renal vasodilator.

Question 89

A high incidence of latex allergy has been found in patients with:

• adenocarcinoma of the breast
• congestive heart failure
• mesothelioma
• spinal bifida

Answer 89

spina bifida

Repeat exposure to latex increases the incidence of latex allergy. Patients with spina bifida, spinal cord injuries, and congenital abnormalities of the genitourinary tract have a very high incidence of latex allergy. This is the presumed result of repeated exposure, especially to urinary catheters.

Question 90

A true statement regarding Lambert-Eaton Myasthenic syndrome is:

• it is difficult to differentiate from myasthenia graves
• muscle weakness improves with repeated effort
• weakness manifests initially in facial muscles
• it is associated most frequently with adenocarcinoma of the lung

Answer 90

muscle weakness improves with repeated effort

Lambert-Eaton Myasthenic Syndrome (LEMS) is a paraneoplastic syndrome associated most frequently with small cell carcinoma of the lung. It results from a presynaptic defect of neuromuscular transmission. Weakness typically begins in the lower extremities and may ascend to include the muscles of respiration. In contrast to myasthenia gravis, muscle weakness improves dramatically with repeated effort, and there is less of a response to anticholinesterase agents.

Question 91

A list of hypersensitivity reactions is shown below. By dragging & reordering the selections in yellow, match the hypersensitivity reaction with its corresponding pathophysiologic event.

Serum Sickness
Transfusion Reactions
Contact Dermatitis
Anaphylaxis

Type I
Type II
Type III
Type IV

Answer 91

Anaphylaxis—>Type I
Transfusion Reaction —> Type II
Serum Sickness—>Type III
Contact Dermatitis—>Type IV

Question 92

Your patient, a 3-year-old weighing 18 kg, is scheduled for an inguinal hernia repair. What is the most appropriate laryngeal mask airway size for this patient?

• 1
• 1.5
• 2
• 2.5

Answer 92

2

LMA sizes for children:
neonates up to 5 kg - 1
infants 5 - 10 kg  - 1.5
children 10 - 20 kg - 2
children 20 - 30 kg - 2.5
children > 30 kg - 3

Question 93

The most common cause of significant hypotension in the post-anesthesia care unit is:

• cardiovascular depression from residual anesthetics
• hypovolemia
• hypoxemia secondary to inadequate ventilation
• sepsis

Answer 93

hypovolemia

Hypovolemia is by far the most common cause of hypotension in the PACU. Mild hypotension may be associated with residual anesthetic effects.

Question 94

Rate the following regional techniques in descending order for degree of systemic absorption of local anesthetic:

• caudal > epidural > intercostal
• intercostal > epidural > caudal
• caudal > intercostal > epidural
• intercostal > caudal > epidural

Answer 94

intercostal > caudal > epidural

Because the intercostal nerves are surrounded by a rich vascular supply, local anesthetics injected into this area will be more rapidly absorbed, thus increasing the likelihood of achieving toxic levels. Other anatomic approaches in descending order of LA absorption are as follows: caudal, epidural, brachial plexus, sciatic-femoral, and subcutaneous.

Question 95

In patients receiving supplemental oxygen, the most common cause of significant hypoxemia in the post-anesthesia care unit is:

• intrapulmonary shunting
• shivering
• inadequate ventilation
• diffusion hypoxia

Answer 95

intrapulmonary shunting

Increased intrapulmonary shunting from a decreased FRC relative to closing capacity is the most common cause of hypoxemia in the PACU.

Question 96

Correct statements regarding the use of phosphodiesterase (PDE III) inhibitors include:

• thrombocytopenia is associated with the use of amrinone
• they cause little increase in heart rate
• they cause a decrease in intracellular calcium stores in the myocardium
• direct myocardial effects are accompanied by prominent vasoconstriction
• PDE III inhibitors are more pro arrhythmic than beta-agonist
• they cause a significant increase in myocardial oxygen consumption

Answer 96

thrombocytopenia is associated with the use of amrinone, they cause little increase in heart rate

Through the inhibition of phosphodiesterase, PDE III inhibitors ultimately interfere with the metabolism of cAMP. The increased levels of cAMP produce a positive ionotropy with a concomitant vasodilation as a result of an increase in intracellular calcium stores in the myocardium. PDE III inhibitors lack significant proarrythmic effects as compared to β-agonists, they improve coronary circulation, and decrease MVO2. Amrinone (but not milrinone) attenuates platelet aggregation and thromboxane activity.

Question 97

Direct effects of acidemia include:

• smooth muscle stimulation
• myocardial depression
• hypertension
• leftward shift in hemoglobin dissociation curve
• decreased threshold for ventricular fibrillation
• hypokalemia
• decreased responsiveness to endogenous catecholamines

Answer 97

myocardial depression, decreased threshold for ventricular fibrillation, decreased responsiveness to endogenous catecholamines

Direct effects of acidemia include direct myocardial depression with vasodilation, hypotension, rightward shift in the hemoglobin dissociation curve, decreased responsiveness to catecholamines, decreased threshold for ventricular fibrillation, and hyperkalemia.

Question 98

Which of the following laboratory findings would be expected in the parturient at term?

• Hbg 15 g/dL
• PaCO2 42 mmHg
• Mild glycosuria
• PaO2 80 mmHg

Answer 98

Mild glycosuria

In the parturient at term, a decreased renal threshold for glucose and amino acids is common and often results in a mild glycosuria or proteinuria. Hemoglobin is decreased by approximately 20% secondary to dilutional anemia, PaCO2 is decreased by 15% and PaO2 increases by 10% due to hyperventilation.

Question 99

Anaphylactoid reactions differ from anaphylaxis in that anaphylactoid reactions:

• are not associated with bronchospasm
• are not associated hypotension
• are not associated with the release of histamine
• do not depend on IgE antibody interaction

Answer 99

do not depend on IgE antibody interaction

Anaphylactoid reactions resemble anaphylaxis, but do not depend on IgE antibody-antigen reactions. Direct release of histamine from mast cells can be caused by certain drugs and have a clinically indistinguishable picture from anaphylaxis.

Question 100

Plasma cholinesterase activity:

• is increased in the parturient at term
• is decreased in the obese patient
• may be inhibited by metoclopramide
• may be inhibited by amino glycoside antibiotics

Answer 100

may be inhibited by metoclopramide

The duration of action of succinylcholine after the administration of metoclopramide, 10 mg IV, is prolonged, reflecting probable inhibition of plasma cholinesterase by metoclopramide. Plasma cholinesterase activity is increased in obese patients and decreased in the parturient at term.

Question 101

Renal compensatory mechanisms during acidemia include: (pick 2)

• decreased excretion of bicarbonate anion
• increased excretion of potassium
• increased reabsorption of titratable acids
• increased formation of ammonia
• decreased H2PO4 excretion

Answer 101

increased formation of ammonia, decreased excretion of bicarbonate anion

Three renal mechanisms come into play during acidemia: increased reabsorption of bicarbonate, increased excretion of titratable acids, and increased formation of ammonia.

Question 102

The most ubiquitous material in the epidural space is:

• vascular tissue
• nervous tissue
• fat
• menigeal tissue

Answer 102

fat

The most ubiquitous material in the epidural space is fat, which is principally located in the posterior and the lateral epidural space. The epidural fat appears to have clinically important effects on the pharmacology of epidurally and intrathecally administered drugs, especially highly lipid-soluble local anesthetics, which may be sequestered in the epidural fat.

Question 103

The rapid termination of effect of adenosine is owed primarily to:

• rapid hepatic metabolism
• rapid redistribution
• rapid uptake and metabolism by erythrocytes and vascular endothelium
• rapid extraction by cardiac tissues

Answer 103

rapid uptake and metabolism by erythrocytes and vascular endothelium

Erythrocytes and vascular endothelial cells rapidly take up adenosine and metabolize it to inosine and adenosine monophosphate. This results in a very short half=live of approximately 10 seconds.

Question 104

The pulmonary flow-volume loop corresponding to restrictive lung disease is:

A
B
C
D

Answer 104

D

Flow-volume loop “B” represents normal lung volumes in the healthy patient. Flow-volume loop “D” corresponds to a restrictive defect (i.e. pulmonary fibrosis). Loop “A” depicts a patient with chronic obstructive pulmonary disease (i.e. emphysema), and loop “C” represents a fixed upper airway obstruction (i.e. tracheal obstruction).

Question 105

Traditionally, patients are considered to be at risk for aspiration of gastric contents if:

• they have ingested clear fluids 4 hours ago
• their gastric contents exceed 25 mL with a pH

Answer 105

their gastric contents exceed 25 ml with a pH

Question 106

The most common surgical emergency encountered during pregnancy is:

• appendicitis
• cholelithiasis
• ureterolithiasis
• ectopic pregnancy

Answer 106

appendicitis

Appendicitis is the most common surgical emergency in the parturient. Incidence varies from 1:350 to 1:10,000. Appendicitis is the reason for approximately 2/3rd of the laparotomies performed during pregnancy.

Question 107

A 45-year-old male is scheduled for laparoscopic inguinal hernia repair. He has a history of diabetes mellitus treated with glyburide. Preoperative instructions should include:

• continue all medications as scheduled with a sip of water
• substitute 10 units of subQ insulin for glyburide on the morning of surgery
• hold dosing of glyburide for 24-48 hour preoperatively
• postpone surgery until the patient is changed to a shorter acting hypoglycemic agent

Answer 107

hold dosing of glyburide for 24 - 48 hours preoperatively

Sulfonylureas and metformin (extended release formulation) should not be used for 24 - 48 hours before surgery because of their long half-lives. These drugs are restarted if renal and hepatic function remain adequate.

Question 108

The capnogram below is indicative of:

• rebreathing
• cardiogenic oscillations
• incomplete paralysis
• esophageal intubation

Answer 108

cardiogenic oscillations

Cardiogenic oscillations occur during the last third of the expiratory phase of the capnogram. They are generally synchronized with the cardiogram and represent mediastinal movement during systole.

Question 109

Corneal damage from accidental ocular exposure to laser scatter is most likely with the:

• argon laser
• YAG laser
• helium-neon laser
• carbon dioxide laser

Answer 109

carbon dioxide laser

Tissue damage from the laser is dependent on its wavelength. Long wave-length laser emissions, such as the carbon dioxide laser, are absorbed by water and thus have little tissue penetration. Shorter wave-length emissions, such as from the YAG and argon lasers, react with pigmented substances such as hemoglobin or retinal cells. Thus the carbon dioxide laser will cause mostly cornea damage whereas the YAG and argon lasers will cause retinal damage. The helium laser is used only to visibly mark the point of laser contact and has no effect on tissues.

Question 110

True statements regarding synthetic polysaccharide solutions for intravenous therapy include:

• they are not associated with anaphylactic reactions
• they may result in a decreased glomerular filtration rate
• they may interfere with platelet aggregation
• they increase blood viscosity
• they cause greater peripheral edema than crystalloid solutions

Answer 110

they may interfere with platelet aggregation, they may result in a decreased glomerular filtration rate

Dextran and hetastarch are synthetic polysaccharide solutions which are used as volume expanders. They are relatively inexpensive, increase effective blood volume, and decrease blood viscosity. However, they impair coagulation by coating platelets, and they impair typing and cross-matching by coating RBCs. Anaphylactic reactions have been associated with their use.

Question 111

The earliest manifestation of migration of the endotracheal tube to an endobronchial position is:

• decreased end-tidal carbon dioxide
• decreased oxygen saturation
• increased peak airway pressure
• increased end-tidal carbon dioxide

Answer 111

increased peak airway pressure

The earliest manifestation of bronchial intubation is an increase in peak inspiratory pressure. Carbon dioxide elimination is not significantly changed since endobronchial intubation causes little change in dead space. Decreased oxygen saturation will occur as blood is shunted across the unventilated lung, but desaturation will occur only after the consumption of the oxygen in the FRC of the unventilated lung.

Question 112

Identify the laryngeal classification system depicted below:

• Wis Foreggar
• Mallampati
• Cormack-Lehane
• McCoy
• Grade I
• Grade II
• Grade III
• Grade IV

Answer 112

Cormack-Lehane

The Cormack Lehane classification depicts the best view of the glottis obtainable during laryngoscopy, assuming correct technique. The frequencies of the grades amongst patients without neck pathology are: Grade I: 99%, Grade 2: 1%, Grade III: 1:2,000, Grade IV: less than 1:100,000.

Question 113

During the resection of a mediastinal mass, the surgeon requests 10 minutes of apneic oxygenation. During this time period the arterial carbon dioxide tension is expected to increase by:

Answer 113

33 - 42 mm Hg

During apneic oxygenation the arterial carbon dioxide tension rises approximately 6 mm Hg during the first minute and 3 - 4 mm Hg for each subsequent minute.

Question 114

During the first stage of labor, visceral pain is transmitted via spinal nerves:

• T4-T10
• T10-L1
• L2-S4
• S2-S4

Answer 114

T10 - L1

Visceral pain is the pain during labor which is produced by uterine contractions and dilation of the cervix. During the first stage of labor, afferent visceral pain impulses from the uterus and cervix travel in nerves that enter the spinal cord at T10 - L1.

Question 115

The desflurane Tec 6 vaporizer:

• has a variable bypass design
• is temperature compensated
• is heated to 35’ C
• has no fresh gas entering the vaporization chamber

Answer 115

has no fresh gas entering the vaporization chamber

As a result of the high vapor pressure of desflurane (664 mmHg at 20o C) variable bypass design was not possible. Instead, the desflurane is heated to 39o C with a vapor pressure of 1500 mmHg. Using pressure monitoring, the flow of desflurane vapor is adjusted to deliver the desired concentration. No fresh gas ever enters the vaporizing chamber.

Question 116

Of the following IV induction agents, the most appropriate choice for the severe asthmatic patient is:

• midazolam
• ketamine
• propofol
• etomidate

Answer 116

ketamine

Ketamine has bronchodilatory activity and has been used in sub-anesthetic doses to treat bronchospasm. In the presence of active bronchospasm, ketamine may be recommended as the IV induction drug of choice.

Question 117

A 36-year-old patient is scheduled for escharotomies of 30% burn injuries to the lower extremities. Alterations in the pharmacology of anesthetic drugs in this patient include:

• increased dosage of succinylcholine is required
• increased dosage of vecuronium is required
• cardiac output is increased by volatile anesthetics
• protein binding of neuromuscular blockers is decreased

Answer 117

increased dosage of vecuronium is required

After 24 hours, succinylcholine is contraindicated in patients with a burn injury and may result in cardiac arrest from hyperkalemia. Nondepolarizing neuromuscular blockers will require a higher than normal dose as a result of an increased volume of distribution and altered protein binding and an increase in extra-junctional receptors. The myocardial depressant effects of volatile agents will be increased in the burn patient.

Question 118

A glossopharyngeal nerve block will anesthetize:

• the posterior third of the tongue
• the epiglottis
• the vallecula
• the posterior rimaglottidis

Answer 118

the posterior third of the tongue

A glossopharyngeal nerve block anesthetizes the posterior third of the tongue, uvula, soft palate, and pharynx, and inhibits the afferent limb of the gag reflex.

Question 119

Management of noncardiogenic pulmonary edema should include:

• elevated levels of PEEP(>35 cm H2O) to open closed Alveoli
• early corticosteroid therapy
• avoidance of high tidal volumes
• maintenance of the lowest acceptable FiO2(

Answer 119

avoidance of high tidal volumes, maintenance of the lowest acceptable FiO2 (

Question 120

Arteries arising directly from the aortic arch include the:

• left common carotid artery
• right common carotid artery
• right vertebral artery
• left vertebral artery
• left subclavian artery
• right subclavian artery
• brachiocephalic artery

Answer 120

brachiocephalic artery, left subclavian artery, left common carotid artery

The aortic arch vessels include the left subclavian, the left common carotid, and the right brachiocephalic, which subdivides into the right common carotid and the right subclavian arteries. Both the right and left vertebral arteries are branches of the corresponding subclavian arteries.

Question 121

Drugs, used in the treatment of diabetes type 2, which increase the secretion of insulin from the pancreas include: (Select 2)

• chlorpropamide
• acarbose
• glipizide
• metformin
• rosiglitazone

Answer 121

chlorpropamide, glipizide

Chlorpropamide and glipizide are a members of the sulfonylurea class of oral hypoglycemic agents and stimulate the release of insulin from the pancreas. Acarbose interfers with the intestinal enzymes that breakdown starches. Metformin decreases hepatic glucose production and increases peripheral insulin utilization. Finally, rosiglitazone has been shown to degrease hepatic glucose output and reduce insulin resistance by sensitizing the insulin receptor.

Question 122

Which of the following conditions is associated with an increased speed of induction with sevoflurane in an 80 kg, 5’9” man?

• a cardiac index of 1.9 L/min/m
• a cardiac output of 6.5 L/min
• Long standing COPD
• Pulmonic atresia

Answer 122

A cardiac index of 1.9 L/min/m2
The formula for anesthetic uptake (loss) is:
loss = Q . λ . (PA-PV) / Pbr (760 mmHg)

Q = flow (cardiac output-CO)
λ = blood:gas solubility of the agent
PA = alveolar partial pressure of the agent
PV = venous partial pressure of the agent

When CO is low, loss of the anesthetic (uptake into the blood) is low and PA rises more rapidly. Since cardiac index (CI) = CO/BSA and a normal CI is 2.5-4.2L/min/m2, a CI of 1.9 L/min/m2 indicates a low CO. Therefore, this particular patient would experience a more rapid inhalation induction.

Question 123

Clinical signs of a 5% dehydration (as a percentage of body weight) include:

• tachycardia > 120/min
• diminished urine output
• blood pressure decreased with respiratory variation
• orthostasis
• dry mucous membranes

Answer 123

diminished urine output, dry mucous membranes

Fluid Loss (expressed as % of body weight)
Sign 5% 10% 15%
mucous membranes dry very dry parched
orthostatic changes none present marked
urine output mildly decreased decreased markedly decreased
pulse rate mildly increased increased markedly increased
blood pressure normal mildly decreased decreased

Question 124

The ventilator spill valve:

• should be open during inspiration
• allows the driving gas inside the housing to be exhausted to the atmosphere
• allows the venting of excess gasses at the end of exhalation
• should remain closed unless circuit pressures exceed 10 cmH20

Answer 124

allows the venting of excess gasses at the end of exhalation

Because the APL is isolated from the breathing system during ventilator operation, a spill valve is used to direct excess gasses in the breathing system to the scavenging system. This valve is closed during inspiration and remains closed until the bellows is fully expanded.

Question 125

A 76-year-old female is scheduled for electroconvulsive therapy (ECT) for refractory depression. Physiological effects of ECT include:

• initial bradycardia followed by tachycardia
• hypotension lasting up to 30 minutes
• decreased intracranial pressure
• decreased oral secretions

Answer 125

initial bradycardia followed by tachycardia

ECT is usually associated with an initial parasympathetic discharge followed by a more sustained sympathetic discharge. The initial phase is characterized by bradycardia and increased secretions. The hypertension and tachycardia that follow are sustained for several minutes. Cerebral blood flow, ICP, intragastric pressure, and intraocular pressure are all transiently increased.