Practice Exam 1

Question 1

The loss of ventricular filling as a result of acute atrial fibrillation is approximately:

Answer 1

15 - 25%
Passive flow accounts for about 75 - 85% of ventricular filling. The remaining 15 - 25% occurs as a result of atrial contraction, which is lost during atrial fibrillation.

Question 2

In the parturient, early decelerations signify:

• cord compression
• vagal stimulation from head compression
• uteroplacental insufficiency
• impending emergency Cesarean delivery

Answer 2

vagal stimulation from head compression
Early decelerations are normal and common. The deceleration pattern matches the contraction with the most deceleration occurring at the peak of the contraction. The FHR rarely goes below 100 beats per minute. The cause of these decelerations is head compression during uterine contractions.

Question 3

In the diagram below, anesthesia of the 5th digit of the hand can be produced by blocking:

Answer 3

The ulnar nerve is represented by ‘D’, and supplies sensory innervation to medial part of the 4th and entire 5th digits. ‘A’ is the axillary nerve, ‘B’ is the radial nerve and ‘C’ is the median nerve

Question 4

Proper induction technique for the infant with tracheoesophageal fistula would include:

• preoxygenation with 100% and PPV
• awake intubation
• ketamine 2 mg/kg
• inhalation induction in the sitting position

Answer 4

awake intubation

Awake intubation offers the greatest degree of safety and does not risk insufflation of the stomach.

Question 5

An acute increase in PaCO2 from 40 mmHg to 80 mmHg will cause an increase in cerebral blood flow of approximately:

Answer 5

85 - 100%
Increasing CO2 causes cerebral vasodilatation and increased cerebral blood flow. Within a range of 20 - 80 mmHg the increase in blood flow is linear. Therefore, doubling the CO2 causes a nearly 100% increase in cerebral blood flow.

Question 6

Which of the following cardiac malformations is associated with Tetralogy of Fallot?

• Left ventricular hypertrophy
• Pulmonic atresia
• Large ASD
• Overriding aorta

Answer 6

Overriding aorta
Tetralogy of Fallot has four key features. A ventricular septal defect and pulmonic stenosis are the most important. Also, the aorta lies directly over (overrides) the ventricular septal defect and the right ventricle is hypertrophic.

Question 7

The release of catecholamines from the adrenal medulla is under the control of the autonomic nervous system. The neurotransmitter controlling the release is:

• norepinephrine
• acetylcholine
• dopamine
• 5-HT

Answer 7

acetylcholine
Preganglionic fibers pass directly into the adrenal medulla without synapsing in a ganglion. Acetylcholine is the neurotransmitter causing the release of catecholamines from the adrenal medulla.

Question 8

The most common cause of postpartum hemorrhage is:

• cervical laceration
• labial hematoma
• placenta accreta
• uterine atony

Answer 8

uterine atony

Question 9

Which of the following has been associated with causing the release of antidiuretic hormone (ADH)?

• Decreased plasma sodium
• Decreased serum osmolality
• Positive pressure ventilation
• Diabetes insipidus

Answer 9

Positive pressure ventilation
Positive pressure ventilation has been associated with the release of ADH. Decreased serum osmolality and decreased sodium will decrease ADH production. Diabetes insipidus is a disease of decreased ADH production.

Question 10

Initial closure of the ductus arteriosus following umbilical cord clamping is the result of:

• a rise in arterial oxygen concentration
• a decrease in placental prostaglandin secretion
• a sudden increase in infant’s SVR
• hypercarbia

Answer 10

a rise in arterial oxygen concentration
The ductus provides shunting of blood flow from the left pulmonary artery to the aorta just beyond the origin of the left subclavian artery. The high levels of oxygen which it is exposed to after birth causes it to close.

Question 11

Manual compression of the reservoir bag is an example of:

• Charle’s Law
• Boyle’s Law
• Gay-Lussac’s Law
• Henry’s Law

Answer 11

Boyle’s Law
With temperature constant, the volume of a gas is inversely proportional to pressure: V is proportional to 1/P or VP = constant. As the gas in the reservoir bag is compressed, the pressure rises and gas is transferred to the patient.

Question 12

Anesthesia of the epiglottis can be produced by local anesthetic block of the:

• recurrent laryngeal nerve
• external branch of the superior laryngeal nerve
• glossopharyngeal nerve
• internal branch of the superior laryngeal nerve

Answer 12

internal branch of the superior laryngeal nerve

Question 13

Stimulation of the baroreceptors results in:

• increased sympathetic tone
• increased myocardial contractility
• increased vagal tone
• increased heart rate

Answer 13

increased vagal tone
The baroreceptors, located in the carotid sinus and aortic arch, respond to stretching from elevated mean blood pressure. When stimulated, the baroreceptors reduce sympathetic tone, inotropy, chronotropy, and SVR, as well as increase vagal tone to further reduce heart rate.

Question 14

Hydrophobic heat and moisture exchangers:

• use a membrane lacking pleating or pores
• are efficient bacterial and viral filters
• have improved performance when used in high ambient temperatures
• are more effect at temperature and heat conservation as compared to hygroscopic heat and moisture exchangers

Answer 14

are efficient bacterial and viral filters
Most heat and moisture exchangers (HME) are of one of two types, hydrophobic or hygroscopic. Hydrophobic HMEs use a pleated hydrophobic membrane with small surface pores. They provide moderately good inspired humidity, but performance may be impaired by high ambient temperatures. Hydrophobic HMEs are also efficient bacterial and viral filters.

Question 15

The anesthetic incidence of MH in children is approximately one patient in:

Answer 15

15000 - 20000 patients

The incidence of MH is 1:15,000 - 20,000 anesthetics in children and 1:40,000 anesthetics in adults.

Question 16

The output of a variable-bypass vaporizer, set to deliver 2% is shown below. Possible causes for the variation of the delivered output from the vaporizer include:

Answer 16

a change in the composition of the fresh gas flow
Changes in fresh gas composition can have an effect on vaporizer output. This is the result of uptake and subsequent release of an introduced gas by the liquid volatile agent in the vaporizer. Temperature changes normally encountered in the operating room do not cause a clinically significant change in vaporizer output.

Question 17

In the evaluation of the patient with pheochromocytoma, 24-hour urine assessment of the metabolic end-products of catecholamines is diagnostic. The major metabolic end-product of catecholamine metabolism is:

Answer 17

vanillylmandelic acid (VMA)
Vanillylmandelic acid (VMA) is excreted in the urine and constitutes about 85% of the metabolites of catecholamines.

Question 18

In the anesthesia machine, components of the low-pressure system include the: (Select 2)

• e-cylinders
• oxygen failure safety device
• flowmeters
• vaporizers
• flush valve
• oxygen pressure alarm

Answer 18

flowmeters, vaporizers

The anesthesia machine can be broadly divided into 3 systems. The low-pressure system contains the flowmeters, the vaporizers, any ancillary oxygen flowmeter and the common gas outlet.

Question 19

A 36-year-old female presents for a laparoscopic cholecystectomy. Her past medical history is significant for glucose-6-phosphate-dehydrogenase deficiency. Her anesthetic management would include the avoidance of:

-nitroprusside
-lidocaine
-desflurane
-tetracaine
-prilocaine
metabolic alkalosis
-cephalosporins

Answer 19

nitroprusside, prilocaine

In patients with G-6-PD deficiency, drugs that can oxidize hemoglobin to methemoglobin should be avoided. These include: prilocaine, nitroprusside, methylene blue, penicillin, sufonamides, quinidine, and doxorubicin.

Question 20

Lab values expected to be elevated in a patient with chronic renal failure include:

• platelet count
• hemoglobin
• plasma carbon dioxide content
• bleeding time

Answer 20

bleeding time
Platelet count may be normal to low in the chronic renal failure patient but an increase in bleeding time is noted secondary to platelet dysfunction, specifically from a decrease in platelet aggregation and adhesion.

Question 21

Determinants of the vapor pressure of volatile anesthetic agents include:

• atmospheric pressure
• altitude
• temperature
• density of the vaporized agent

Answer 21

temperature
Vapor pressure (VP) is independent of atmospheric pressure or altitude. VP depends only on the physical characteristics of the liquid and its temperature. VP increases with increases in temperature.

Question 22

Halogenation of volatile anesthetic agents:

• decreases flammability
• decreases potency
• results in the formation of an ether
• involves the substitution of iodine for hydrogen

Answer 22

decreases flammability
Halogenation refers to the substitution of a halogen atom in place of a hydrogen atom. Although iodine is a halogen, the atom is too big for use in volatile anesthetics. Halogenation decreases flammability and increases anesthetic potency.

Question 23

The train-of-four tracing below was obtained after the administration of:

• succinylcholine
• vecuronium
• rocuronium
• atracurium

Answer 23

succinylcholine
Characteristics of depolarizing blockade include: decreased twitch height, absence of fade, and minimal reduction in twitch height (T4:T1 > 0.7).

Question 24

Of the following organs, the most likely to be injured during extracorporeal shockwave lithotripsy is:

• lungs
• heart
• liver
• spleen

Answer 24

lungs
During ESWL, repetitive high energy sound waves are aimed at the nephrolithiasis, causing it to fragment. Because tissue has the same acoustic density as water, damage does not generally occur. However, tissue destruction can occur if the waves are focused at air-tissue interfaces such as in the lung and the intestine.

Question 25

During intraoral laser surgery, ignition of the endotracheal tube occurs. By dragging & reordering the selections in yellow, match & place in correct order the steps that should be taken. - Extinguish with saline - Remove burning material - Mask ventilate - Stop gas flow

Answer 25

Remove burning material---Step 1 - Stop gas flow---Step 2 - Extinguish with saline---Step 3 - Mask ventilate---Step 4

Question 26

The greatest decreases in hepatic blood flow occur with: - proximity of the operative site to the liver - isoflurane anesthesia - regional anesthesia - desflurane anesthesia

Answer 26

proximity of the operative site to the liver Inhaled anesthetics and regional anesthesia reduce hepatic blood flow by approximately 20-30%; halothane > isoflurane. Surgical procedures near the liver can reduce HBF up to 60%.

Question 27

Signs consistent with cardiogenic shock include: - increased pulmonary artery occlusion pressure - decreased systemic vascular resistance - increased cardiac index - decreased myocardial oxygen demand - redistribution of the blood volume away from the heart and lungs - venous congestion

Answer 27

increased pulmonary artery occlusion pressure, venous congestion Characteristics of cardiogenic shock include increased PAOP, low CI, and increased SVR. Also present are venous congestion, reflex vasoconstriction and a redistribution of blood volume toward the heart and lungs.

Question 28

Correct statements concerning the geriatric patient include: - hypothalamic temperature centers remain essentially intact - body fat decreases with increasing age - a glomerular filtration rate of 70 mL/min may be within normal limits - physiologic dead space is decreased in the elderly patient

Answer 28

a glomerular filtration rate of 70 mL/min may be within normal limits Renal blood flow and GFR decrease by between 1-2% per year after the age of 25 years. (Normal GFR is 125 mL/min.) Aging impairs central temperature regulation. Body fat content and physiologic dead space increase with age.

Question 29

Major criteria for the diagnosis of fat embolism syndrome include: (Select 3) - cerebral changes - retinal fat emboli - urinary fat globules - axillary/subconjunctival petechiae - hypoxemia - tachycardia - increased erythrocyte sedimentation rate - hyperthermia

Answer 29

hypoxemia, cerebral changes, axillary/subconjunctival petechiae Major diagnostic criteria for fat embolism include axillary/subconjunctival petechiae, hypoxemia, CNS depression and pulmonary edema.

Question 30

Conditions commonly associated with painless vaginal bleeding include: - placenta previa - abruptio placenta - HELLP syndrome - pregnancy-induced hypertension

Answer 30

placenta previa Placenta previa is an obstetric complication that occurs in the second and third trimesters of pregnancy. It is one of the leading causes of painless vaginal bleeding in the second and third trimesters.

Question 31

A 32-year-old male develops polyuria in the post-operative period following a transphenoidal resection of a pituitary adenoma. Laboratory data includes a urine sodium concentration of 11 mEq/liter and a serum sodium concentration of 145 mEq/liter. The appropriate treatment is: - administration of ACTH - administration of hydrocortisone - administration of DDAVP - administration of an insulin infusion

Answer 31

administration of DDAVP Injury to the pituitary gland during transphenoidal surgery can produce deficiencies in any of the hormones from either the anterior or posterior pituitary. In this patient with polyuria with dilute urine in the face of an elevated serum sodium, diabetes insipidus is the most likely diagnosis.

Question 32

The normal alveolar-to-arterial (A-a) partial pressure gradient for a 70-year-old is approximately:

Answer 32

20 mmHg The normal A-a partial pressure gradient for oxygen increases from 8 mm Hg at age 20 years to approximately 20 mm Hg at age 70 years. An estimate of the A-a gradient can be made using: A-a gradient = (Age +4) / 4

Question 33

The function of the regulator in line with the input from the oxygen e-cylinders is to: - reduce variable high pressure input to constant low pressure output - reduce constant high pressure input to variable low pressure output - reduce the pressure from the e-cylinders to match the pressure from the wall outlet - prevent retrograde filling of any other attached oxygen cylinders

Answer 33

reduce variable high pressure input to constant low pressure output Pressure regulators reduce variable high pressure input to constant low pressure output. The pressure from the cylinders is reduced to below that of the wall outlet gas supplies so that the wall outlets are preferentially used if both sources are available.

Question 34

As the volume of distribution at steady state of a drug increases: - half-life increases - clearance increases - half-life decreases - clearance decreases

Answer 34

half-life increases Half-life = (0.693)(volume of distribution)/clearance. Increases in volume of distribution increase half-life, while increases in clearance decrease half-life.

Question 35

You are asked to evaluate an 86-year-old man following an inguinal hernia repair performed with monitored anesthesia care and minimal sedation. The rhythm strip below is obtained. The most appropriate therapy is: - observation - atropine - morphine - transvenous pacing

Answer 35

transvenous pacing Second degree heart block, type 2 is characterized by constant P-P and R-R intervals prior to the dropped QRS complex. Acute onset second degree heart block, type 2 is usually associated with MI and can rapidly progress to 3rd degree block. Atropine is characteristically not effective and pacing is indicated.

Question 36

You are asked to evaluate a 37-year-old, 180-kilogram male scheduled for gastric banding. During examination of the airway you are able to visualize the hard palate, soft palate and base of the uvula. The corresponding Mallampati classification is:

Answer 36

III Visualized oral structures in the Mallampati classification are: I - soft palate, fauces, uvula, tonsillar pillars II - soft palate, fauces, uvula III - soft palate, base of uvula IV - hard palate only.

Question 37

A list of adrenergic agonists is shown below. By dragging & reordering the selections in yellow, match the agonist of with its corresponding receptor. - Phenylephrine -beta(non selective) - Dexmedetomidine -alpha 1 - Isoproterenol -alpha 2 - Terbutaline -beta 2

Answer 37

- Phenylephrine alpha 1 - Dexmedetomidine -alpha2 - Isoproterenol -beta(non selective) - Terbutaline -beta 2

Question 38

Hemodynamic signs commonly seen in the patient with end stage liver disease include: - bradycardia - increased cardiac output - increased systemic vascular resistance - systolic hypertension

Answer 38

increased cardiac output | Patients with cirrhosis and ESLD often exhibit low SBPs (90 - 110 mmHg) , low PaO2 (

Question 39

A 56-year-old man is being treated with sodium nitroprusside for control of elevated blood pressure following a craniotomy. He has been treated for the previous 36 hours and the current rate of infusion is 10 micrograms/kg/min. His blood pressure is 165/96 and pulse rate is 115/min. Additional findings you would expect include: - metabolic acidosis - respiratory acidosis - elevated methemoglobin levels - increased mixed venous oxygen content - tachyphylaxis - decreased oxygen saturation as measured by pulse oximetery

Answer 39

tachyphylaxis, metabolic acidosis, increased mixed venous oxygen content Cyanide intoxication must be suspected when the dose of nitroprusside exceeds 1 mg/kg over a 2-hour period or 0.5mg/kg/hour over 24 hours. Metabolic acidosis, elevated mixed venous oxygen saturation, and tachyphylaxis would indicate toxicity.

Question 40

The pressure in an e-cylinder of oxygen is found to be 500 psi. If an anesthetic is being delivered using 2 L/min of oxygen flow, the cylinder will last approximately:

Answer 40

80 - 90 minutes The contents of the oxygen e-cylinder can be estimated by the following formula: Capacity (L) / Service Pressure = Contents Remaining (L) / Gauge Pressure: 660 L / 1900 psi = Contents Remaining / 500 psi Contents Remaining = 174 L; @ 2 L/min consumption = 87 minutes of use

Question 41

Depression of the oxygen flush button delivers approximately:

Answer 41

35 - 75 L/min Depression of the flush button delivers 35 - 75 L/min at up to 60 psi. Extreme caution is necessary when the oxygen flush is used, so as to avoid barotrauma.

Question 42

Difficult airway management and intubation is associated with: (choose 3) - Treacher-Collins - Pierre-Robin - Klippel-Feil - Cystic Fibrosis

Answer 42

Treacher-Collins syndrome, Pierre-Robin syndrome, Klippel-Feil syndrome Treacher-Collins syndrome consists of mandibulofacial dysostosis. Pierre-Robin syndrome consists of micrognathia and glossoptosis. Klippel-Feil syndrome is characterized by cervical fusion and immobility. All can result in difficulty with airway management and intubation.

Question 43

In the geriatric patient, a significant prolongation of the elimination half-life is seen with: - succinylcholine - diazepam - propofol - desflurane

Answer 43

diazepam Aging increases the volume of distribution for all benzodiazepines, which prolongs their elimination half-lives. Diazepam's elimination half life may approach 36 - 72 hours. Elderly patients also exhibit enhanced sensitivity to benzodiazepines, which may lead to prolonged postoperative confusion.

Question 44

The upward slope of Phase III of the capnogram below is secondary to: - obstructive airway disease - restrictive airway disease - exhaled gas from lung units with lower V/Q ratios - exhaled gas from lung units with higher V/Q ratios

Answer 44

exhaled gas from lung units with lower V/Q ratios On the capnogram, Phase I is the inspiratory baseline and represents fresh gas from the anesthesia machine. Phase II, or the expiratory upstroke is CO2-rich alveolar gas. Phase III is the expiratory plateau and has an upward slope as lung units with lower V/Q ratios have time to empty. Finally, Phase IV is the inspiratory downstroke as the flow of fresh gas rapidly washes the CO2 away.

Question 45

An ultrasound of the right ilioinguinal region is shown below. The femoral nerve is best represented by:

Answer 45

B In the figure above, A represents the iliopsoas muscle, B represents the femoral nerve, C represents the femoral artery and D represents the femoral vein.

Question 46

Common postoperative complications following carotid endarterectomy include: - glossopharyngeal nerve injury - hypertension - bradyarrhythmia - esophageal perforation

Answer 46

hypertension Between 10% - 66% of patients will experience postoperative hypertension following CEA. The cause appears to involve alteration of the carotid sinus baroreceptors. Other common complications include MI and CVA. Hypotension and bradyarrhythmias are much less common. Esophageal perforation as a complication is rare.

Question 47

You are evaluating a patient for resection of a mandibular tumor under general anesthesia with controlled hypotension. Possible postoperative complications you would inform the patient of include: - renal failure - myocardial infarction - hypercortisolism - acute pancreatitis - blindness - pericarditis with effusion

Answer 47

renal failure, myocardial infarction, blindness Complications from controlled hypotension include: hemiplegia, CVA, ATN, MI, cardiac arrest, hepatic necrosis, and blindness.

Question 48

During repair of an ascending aortic arch aneurysm, deep hypothermic cardiac arrest is needed. It is recommended that the patient be cooled to:

Answer 48

15 - 22 degrees C. Cerebral perfusion must be temporarily interrupted during aortic arch repair. Deep hypothermic cardiac arrest (DHCA) is the most important therapeutic intervention to prevent cerebral ischemia. During DHCA, nasopharyngeal temperatures are measured and the patient is cooled to 15 - 22o C. Arrest periods of up to 25 minutes are generally considered safe.

Question 49

The primary cause of maternal mortality in patients with pregnancy-induced hypertension is: - congestive heart failure - myocardial infarction - pulmonary edema - intracerebral hemorrhage

Answer 49

intracerebral hemorrhage All types of cardiovascular complications can be seen with PIH, however intracerebral hemorrhage is the most common cause of mortality.

Question 50

During the administration of an intravenous regional block, a double tourniquet is commonly used to: - increase systemic redistribution of the anesthetic - increase local anesthetic tissue penetration beneath the tourniquet - reduce the incidence of tourniquet pain - allow the use of concentrated local anesthetic solutions

Answer 50

reduce the incidence of tourniquet pain It is common for tourniquet pain to develop in patients receiving an IV block after about 25 - 30 minutes. If a double tourniquet is used, the distal tourniquet can be inflated and the proximal tourniquet deflated allowing an additional 15 - 20 minutes of relief from the tourniquet pain.

Question 51

A 46-year-old female is scheduled for laparoscopic cholecystectomy. During the preoperative evaluation, the patient admits to having taken "Phen-Fen" over a 5-month period for weight control when she was 36 years of age. You should specifically inquire about: - psychiatric illness - malignant hyperthermia - valvular heart disease - visual changes

Answer 51

valvular heart disease Although never approved for use, the combination of dexfenfluramine and phentermine, "Phen-Fen", was used for short-term weight control. It was later found that Phen-Fen was associated with valve disease.

Question 52

At which stage of gestation is maternal CO the greatest? - First trimester - Second trimester - Third trimester - Immediately following delivery

Answer 52

Immediately following delivery During the first trimester cardiac output is 30-40% higher than in the non-pregnant state. Steady rises are seen, from an average of 6.7 L/minute at 8 - 11 weeks to about 8.7 L/minute flow at 36 - 39 weeks. During labor, further increases are seen with pain in response to increased catecholamine secretion. Also during labor, there is an increase in intravascular volume by 300 - 500 ml of blood from the contracting uterus to the venous system. Following delivery, this autotransfusion compensates for the blood losses and tends to further increase cardiac output by 50% of pre-delivery values.

Question 53

A 37-year-old patient with a history of regional enteritis is undergoing a small bowel resection. During the resection the surgeon expresses difficulty with the anastomosis because of increased bowel activity. Appropriate therapy would include the administration of: - vecuronium - glycopyrrolate - metoclopramide - positive end expiratory pressure

Answer 53

glycopyrrolate Activity of the bowel is under the control of the autonomic nervous system, with the parasympathetic system causing increased activity. Anticholinergic agents, such as glycopyrrolate and atropine, will decrease bowel motility.

Question 54

Ventilatory and blood gas results that suggest a patient is a suitable candidate for pneumonectomy include a: - PaCO2 of 48 mmHg - maximum VO2 of 21 mL/kg/min - FEV1/FVC of 45% - PaO2 of 61 mmHg

Answer 54

maximum VO2 of 21 mL/kg/min

Question 55

Emergent control of the airway using the Seldinger catheter/wire/dilator technique is best accomplished at:

Answer 55

The cricothyroid membrane is located inferiorly to the thyroid cartilage and is the area of choice for the emergent placement of a surgical airway.

Question 56

Carbon monoxide poisoning has been reported when delivering inhaled anesthesia with: - desflurane - a freshly changed sodalite absorber - nitrous oxide - Amsorb Plus used as the carbon dioxide absorbent - desiccated carbon dioxide absorbent

Answer 56

desflurane, desiccated carbon dioxide absorbent Although CO production has been shown to occur with all volatile agents, the greatest amount of production is with desflurane. This usually occurs on Monday morning after fresh gas flow has thoroughly dried the soda lime over the weekend. The new absorbent, Amsorb Plus, does not cause the production of carbon monoxide or compound A.

Question 57

Proper placement of a laryngeal mask airway will result in: - a leak with positive pressure ventilation exceeding 15 cm H2O - an intracuff pressure greater than 60 cm H2O - the tip of the mask resting against the upper esophageal sphincter - the sides of the mask resting against the pyriform fossae - the aperture of the mask aligned with the rim glottis - reliable occlusion of the esophageal inlet

Answer 57

the tip of the mask resting against the upper esophageal sphincter, the sides of the mask resting against the pyriform fossae, the aperture of the mask aligned with the rima glottis The properly inserted LMA should lie with the mask tip resting against the upper esophageal sphincter, the sides facing the pyriform fossae, and the upper border under the base of the tongue. The epiglottis may point up, down, or lie in the bowl of the mask. Mask inflation causes the whole device to move upward slightly and brings the glottic and LMA apertures in line with each other. The seal created by the LMA should allow positive pressure ventilation up to 20 cm H2O. Intracuff pressure should never exceed 60 cm H2O.

Question 58

In the anesthetized patient, the most commonly injured peripheral nerve is the: - common peroneal nerve - femoral nerve - ulnar nerve - sciatic nerve

Answer 58

ulnar nerve The most common peripheral nerve injury is ulnar neuropathy. Persistent ulnar neuropathy occurs in approximately 1:2,700 patients.

Question 59

Cardiopulmonary effects of peritoneal insufflation for laparoscopic surgery include increased: - venous return to the heart - atelectasis - lung compliance - cardiac output - systemic vascular resistance - intrapulmonary shunting

Answer 59

systemic vascular resistance, atelectasis, intrapulmonary shunting Cardiopulmonary consequences to peritoneal insufflation include reduced venous return, increased SVR, decreased CO with increased PAOP (especially in ASA III - IV patients), increased atelectasis, decreased FRC and increased intrapulmonary shunting.

Question 60

The greatest risk of intraoperative recall and awareness occurs during general anesthesia for: - acute trauma patients - cardiac surgery - cesarean section - total joint replacement

Answer 60

acute trauma patients As a result of the minimal anesthesia often given to acutely traumatized patients, the incidence of awareness is over 43%. The incidence of awareness for cardiac surgery and C-section is 1.5% and 0.4% respectively.

Question 61

Near-infrared spectroscopy is: - effective in assessing intracranial hemoglobin oxygen concentration - effective in assessing cerebral electrical activity - accomplished by placing a probe through a small burr hole - unable to assess intracranial blood volume

Answer 61

effective in assessing intracranial hemoglobin oxygen concentration NIRS is a method of analyzing brain hemodynamics, especially hemoglobin oxygenation and blood volumes. NIRS can better penetrate deep into thick tissues, allowing noninvasive physiologic interpretation of oxygenation by evaluating the transmission and absorption of infrared light in the hemoglobin in brain tissue.

Question 62

In the United States, the incidence of intraoperative awareness is approximately:

Answer 62

0.1 - 0.4%

Question 63

Using the figure below, the transition between dead space gas and alveolar gas is best represented by: (Make your selection by clicking on the appropriate part of the figure)

Answer 63

Phase II, the expiratory upstroke, begins at the end of the Phase I, the inspiratory baseline, and ends at Phase III, the expiratory plateau. It is in Phase II that the transition from dead space gas and alveolar gas occurs.

Question 64

In the burn patient, the dosing requirement of nondepolarizing neuromuscular blockers is: - decreased because of decreased extracellular fluid volume - decreased because of decreased receptor sensitivity to acetylcholine - increased because of decreased extracellular fluid volume - increased because of the presence of exntrajunctional receptors

Answer 64

increased because of the presence of exntrajunctional receptors Burn patients and patients with lower motor neuron injury develop extrajunctional receptors. These receptors are very sensitive to succinylcholine and resistant to nondepolarizing blockers.

Question 65

Signs and symptoms commonly associated with epiglottitis include: - barking cough with stridor - abdominal distention and pain - acute dyspnea - low grade fever

Answer 65

acute dyspnea Common signs and symptoms of epiglottitis include: acute onset of fever, dysphagia, dyspnea, drooling, muffled voice, and preference for the sitting position with head leaning forward.

Question 66

The fetal tracing below is associated with: - cord compression - vagal stimulation - uteroplacental insufficiency - maternal atropine administration

Answer 66

uteroplacental insufficiency This tracing is of late decelerations, which is associated with uteroplacental insufficiency. It is believed that the reduction in fetal heart rate is the result of fetal myocardial ischemia and characteristically occurs 20-30 seconds after the start of the uterine contraction. With early decelerations the heart rate slows with the beginning of the uterine contraction and is secondary to increased vagal tone from head compression. Variable decelerations are secondary to cord compression.

Question 67

The most commonly occurring type of tracheo-esophageal fistula is: - I - IIIA - IIIB - IIIC

Answer 67

IIIB TE-fistula type IIIB accounts for 87% of the TE fistulas seen.

Question 68

In the geriatric patient, the most rapid increase in lung capacity is seen in: - closing capacity - vital capacity - functional residual capacity - total lung capacity

Answer 68

closing capacity In the elderly patient, airway collapse increases residual volume and closing capacity. Closing capacity exceeds functional residual capacity, resulting in a ventilation/perfusion mismatch. VC and TLC both decrease with aging.

Question 69

A 22-year-old female presents to the OR with a ruptured ectopic pregnancy. Her medical history is remarkable for major depressive disorder. Her medications include phenelzine and prenatal vitamins. Intraoperatively, agents that should be avoided include: - fentanyl - meperidine - phenylephrine - droperidol

Answer 69

meperidine Phenelzine (Nardil) is a monoamine oxidase inhibitor (MAOI). A serious reaction between MAOI's and meperidine has been reported, which may result in the development of hyperthermia, seizures, and coma.

Question 70

The laboratory test most reflective of the glomerular filtration rate is: - BUN - serum potassium - creatinine clearance - urine protein content

Answer 70

creatinine clearance | Creatinine clearance is the most reliable measurement for accurate assessment of the GFR.

Question 71

A 6-year-old, 25 kg male is undergoing a tonsillectomy. With currently used surgical techniques, the expected blood loss would be approximately:

Answer 71

100 mL | The average blood loss during tonsillectomy is 4 mL/kg. This constitutes over 5% of the total blood volume.

Question 72

The most common complication associated with mediastinoscopy is: - hemorrhage - pneumothorax - phrenic nerve injury - recurrent laryngeal nerve injury

Answer 72

hemorrhage | Hemorrhage is the most common complication of mediastinoscopy occurring in about 0.77% of cases.

Question 73

In the figure below, the LMA-ProSeal is best represented by: (Make your selection by clicking on the appropriate part of the figure)

Answer 73

The LMA-ProSeal has four main parts: cuff, inflation line, airway tube and drain tube. The drain tube is parallel and lateral to the airway tube and allows gasses to escape from the stomach. In addition, the drain tube allows access to the esophagus and stomach.

Question 74

Transient blindness after transurethral resection of the prostate has been associated with the use of: - saline irrigation - sorbitol irrigation - distilled water irrigation - glycine irrigation

Answer 74

glycine irrigation | Visual disturbances including blindness have been reported after the use of glycine irrigation during TURP.

Question 75

A 46-year-old female becomes extremely bradycardic during a blepharoplasty. The most appropriate initial intervention would be: - the administration of 0.4 mg of atropine IV - hyperventilation - infiltration of the orbit with local anesthetic - to ask the surgeon to cease surgical stimulation

Answer 75

to ask the surgeon to cease surgical stimulation The oculocardiac reflex consists of a trigeminal (V) afferent and vagal (X) efferent pathways (A.K.A."the five and dime reflex"). It occurs from traction of the extra ocular muscles and/or pressure on the periorbital area. It may elicit a wide variety of cardiac dysrhythmias including bradycardia, ventricular ectopy, V-fib, and sinus arrest. Primary management consists of immediate notification of the surgeon and temporary cessation of surgical stimulation.

Question 76

A list of lung volumes & capacities in the average adult is shown below. By dragging & reordering the selections in yellow, match the volume of gas with its corresponding lung volume/capacity. - total lung capacity - vital capacity - FRC - residual volume - 1200 mL - 2300 mL - 5800 mL - 4500 mL

Answer 76

5800 mL TLC 4500 mL VC 2300 mL FRC 1200 mL RV

Question 77

Regional anesthetic techniques best avoided in patients receiving positive pressure ventilation include: - thoracic epidural - interpleural block - stellate ganglion block - lumbar paravertebral block

Answer 77

interpleural block Needle location required to achieve an interpleural block puts the patient at high risk for pneumothorax if positive pressure ventilation is being delivered.

Question 78

The most effective intervention in preventing maternal hypotension is: - supine positioning with left uterine displacement - phenylephrine 100 mcg IV - ephedrine 10 mg IV - one liter IV fluid bolus with normal saline

Answer 78

supine positioning with left uterine displacement

Question 79

An 80-year-old patient becomes hypotensive the after administration of an intrathecal dose of 12 milligrams of tetracaine. Ephedrine 10 mg IV is administered with little effect on the BP. Possible reasons for this would include: - inadequate dose of ephedrine - resistance to beta adrenergic agents seen in the elderly population - inappropriately large dose of tetracaine - decreased plasma norepinephrine seen in the elderly population

Answer 79

resistance to beta adrenergic agents seen in the elderly population Elderly patients exhibit decreasing responses to beta-adrenergic agents due to what is known as an endogenous beta-blockade. Circulating norepinephrine levels are increased in the elderly. Ephedrine 10 mg IV and tetracaine 12 mg intrathecally are commonly employed doses.

Question 80

Common findings in patients with hepatorenal syndrome include: - a recent history of aggressive IV fluid therapy - low urine sodium content - markedly reduced urine output - irreversible renal failure

Answer 80

low urine sodium content Hepatorenal syndrome is seen in patients with end-stage liver disease and portal hypertension. The syndrome is commonly associated with a preceding event that reduced plasma volume, eg. diuresis or GI bleed. Urine volume is only slightly diminished however, urine sodium falls to nearly zero. Histologically, the kidneys are intact and function normally if transplanted.

Question 81

The most common viral disease from blood transfusion is: - hepatitis B - AIDS - hepatitis C - cytomegalovirus

Answer 81

cytomegalovirus. The rate of viral transmission of cytomegalovirus is reported to be 1- 3%. Hepatitis B transmission is approximately 1:366,500; the rate of infection with hepatitis C is approximately 1:1,657,700; and, the rate of infection with HIV is approximately 1:1,860,800 Since routine screening of donors for HIV, the incidence of HIV infection from blood transfusion has fallen to about 5 cases per year.

Question 82

A 48-year-old, 71 kg woman is scheduled for a hysterectomy. Her preoperative hematocrit was found to be 40%. The day following surgery, her hematocrit is 30%. Her estimated blood loss is -

Answer 82

1200 - 1500 mL Estimated blood volume for a 71 kg female = (71 kg x 70 mL/kg blood volume) EBL = (Kg x EBV/Kg) x (HCT(start) - HCT(final)) / HCT(average) EBL = (71 x 70) x (40 - 30)/35 EBL = 1420 mL

Question 83

The cell type primarily responsible for surfactant production is: - capillary endothelial cells - alveolar epithelial cells Type I - alveolar epithelial cells Type II - alveolar macrophages

Answer 83

alveolar epithelial cells Type II Surfactant is produced by Type II alveolar epithelial cells. These cells also secrete cytokines and contribute to pulmonary inflammation.

Question 84

Neuroleptic malignant syndrome: - has not been associated with metoclopramide administration - can be effectively treated with dantrolene - has a mortality rate of 5 - 10% - is easily differentiated from malignant hyperthermia

Answer 84

can be effectively treated with dantrolene Neuroleptic malignant syndrome is a rare complication of antipsychotic therapy which may mimic MH. It has a mortality rate of 20 - 30% Muscle rigidity, hyperthermia, rhabdomyolysis, ANS instability, and altered consciousness may be noted. It may be precipitated by metoclopramide and meperidine. Treatment with dantrolene appears to be effective.

Question 85

A 56-year-old, 100-kg male is scheduled for appendectomy. During rapid-sequence induction, difficulty is encountered with endotracheal tube placement with subsequent oxyhemoglobin desaturation. The most appropriate action would be: - awake intubation - cricothyroidotomy - positive pressure pressure with up to 50 cm H2O - positive pressure pressure with up to 25 cm H2O

Answer 85

positive pressure with up to 25 cm H2O pressure Difficulties encountered during rapid-sequence induction that result in desaturation may be resolved with gentle positive pressure ventilation with continued cricoid pressure. Positive-pressure ventilation should not exceed 25 cm H2O to minimize the risk of gastric distention and regurgitation.

Question 86

The plasma of stored blood experiences an increase in: - calcium concentration - potassium concentration - pH - factors V and VIII

Answer 86

potassium concentration Calcium, pH, factors V and VIII, and 2,3-DPG all decrease in the plasma of stored blood. Potassium, lactate, microaggregates and hemoglobin all increase in the plasma of stored blood.

Question 87

The potency of a local anesthetic agent is best correlated with the: - pH of the agent - pKa of the agent - protein binding of the agent - lipid solubility of the agent

Answer 87

lipid solubility of the agent Potency is related to hydrophobicity and physiochemical properties of the agent. In general, more potent agents are more lipid soluble.

Question 88

Hypotension may be seen during rapid infusion of packed red cells as a result of acutely depressed: - sodium levels - potassium levels - calcium levels - catecholamine levels

Answer 88

calcium levels When large volumes of stored blood (more than one blood volume) are administered rapidly, the citrate can cause a temporary reduction in ionized calcium levels resulting in hypotension.

Question 89

A list of pain syndromes is shown below. By dragging & reordering the selections in yellow, match the pain syndrome with its corresponding clinical characteristic. - CRPS II - CRPS I - Myofascial Syndrome - Herpetic Neuralgia - Preceding Nerve Injury - Gradual Onset - Trigger Point Present - Dermatome Distribution

Answer 89

Complex regional pain syndrome type I (CRPS I) is gradual in onset with characteristics that include: burning pain, decreased range of motion, hyperpathia, antecedent injury with little correlation to the severity of symptoms, and relief with adrenergic blockade. CRPS II has identical signs & symptoms, but is usually acute in onset, following a proximal nerve injury.

Question 90

A 6-year-old is scheduled for tonsillectomy under general anesthesia. In preparation for the anesthetic the circuit is to be primed with 50% nitrous oxide, 50% oxygen and 4% sevoflurane. To prime the circuit, the flows are set to 2 L/m nitrous oxide, 2 L/m oxygen and 4% sevoflurane. If the volume of the circuit is 4 liters, the time needed to prime the circuit to achieve 95% of the desired anesthetic concentration is:

Answer 90

3 minutes To determine the time necessary to prime the circuit, the time constant (τ) must be determined. τ = Volume/Flow. Since the volume = 4 L and the flow is 4 L/m the time constant is 1 minute. Each time constant changes the concentration in the circuit by 63.2%. Therefore, after 1 time constant, 63.2% of the desired concentration is obtained; after 2 time constants, 86.5% of the desired concentration is obtained; and after 3 time constants, 95% of the desired concentration is achieved.

Question 91

As compared to the normal ventricular flow-volume loop (purple), the left ventricular flow-volume loop shown in yellow is indicative of: - aortic regurgitation - aortic stenosis - mitral regurgitation - mitral stenosis

Answer 91

aortic stenosis This loop demonstrates increased LV pressures and prolonged LV ejection.

Question 92

Ten milliliters of blood with a saturation of 75% is mixed with ten milliliters of blood with a saturation of 25%. The resultant PaO2 of the mixture is approximately:

Answer 92

26 - 27 mmHg The mixture will have a saturation of 50%. This corresponds to the P50, which is 26 - 27 mmHg.

Question 93

A 18-year-old female is scheduled for spinal fusion for the management of scoliosis. Monitoring will include both somato-sensory and motor evoked potential monitoring. Regarding motor evoked potential monitoring: - it is much more resistant to the effects of general anesthesia than somatosensory evoked potential monitoring - clinical decision making is done on amplitude changes alone - deep neuromuscular blockade is possible during the case - magnetic stimulation is most commonly used while the patient is receiving general anesthesia

Answer 93

clinical decision making is done on amplitude changes alone Motor and sensory evoked potential monitoring are complimentary, allowing assessment of both ascending and descending pathways. Motor evoked potentials (MEP) must be produced with electrical stimulation, since magnetic stimulation is not effective while the patient is under general anesthesia. MEPs are very sensitive to the effects of inhalational anesthetics and most centers use only intravenous anesthetic techniques. In addition, latency of response has little value in clinical decision making, and signal amplitude alone is used to assess the descending pathways.

Question 94

The use of acrylic bone cement has been associated with intraoperative hypotension. This is the result of: - an allergic response to the bone cement - vagal stimulation secondary to circulating red cell lysis - absorption of methyl methacrylate monomer - absorption of methacrylate acid - sympathetic stimulation secondary to polymerized cement - embolization of air and bone marrow

Answer 94

absorption of methyl methacrylate monomer, absorption of methacrylate acid, embolization of air and bone marrow The use of bone cement is associated with hypotension secondary to absorption of the volatile methyl methacrylate monomer, embolization of air and bone marrow, lysis of cells and marrow by the exothermic reaction of the cement, and the conversion of methyl methacrylate to methacrylic acid.

Question 95

During the preoperative evaluation of a 68-year-old woman you discover that she was treated with doxorubicin for carcinoma of the breast 5 years ago. Important additional information you would obtain includes: - a history of pulmonary fibrosis - a history of cardiomyopathy - a history of peripheral neuropathy - a history of acute loss of vision

Answer 95

a history of cardiomyopathy Late toxicity from doxorubicin involves cardiomyopathy and is seen with doses that exceed 550 mg/m2.

Question 96

A 49-year-old woman is scheduled for a right mastectomy with axillary node dissection. Your anesthesia plan would include the avoidance of: - deep neuromuscular blockade - etomidate - beta blockade - preoperative sedation

Answer 96

deep neuromuscular blockade During axillary node dissection, identification of the long thoracic and thoracodorsal nerves may be necessary. This is most effectively done with nerve stimulation and thus contraindicates the use of deep neuromuscular blockade during the case.

Question 97

During an inhalation induction, 2 MAC of volatile anesthetic agent is being delivered. The longest induction time will be achieved with: - N2O - desflurane - sevoflurane - isoflurane

Answer 97

isoflurane Isoflurane has the highest blood/gas solubility of all of the inhalation agents listed. (isoflurane 1.4, N2O 0.47, desflurane 0.42, sevoflurane 0.65). Lower blood/gas solubility corresponds directly to quicker inhalation induction times because the agent is taken up by the blood less avidly and the alveolar concentration of the agent rises more quickly.

Question 98

The intravenous administration of acetylcholine would result in: - decreased insulin secretion - relaxation of the urinary bladder sphincter - decreased detrusor muscle tone - mydriasis

Answer 98

relaxation of the urinary sphincter Acetylcholine (ACh) is the chief neurotransmitter of the parasympathetic nervous system therefore, its effects are synonymous with PNS effects. ACh causes a relaxation of the bladder sphincter with an attendant contraction of the detrusor muscle, causing micturition. Insulin secretion is increased, and miosis is noted from contraction of the iris sphincter.

Question 99

The most important factor determining the spread of local anesthetic in the subarachnoid space is: - baricity relative to the patient position - rate of speed of injection - height of the patient - volume of anesthetic injected

Answer 99

baricity relative to the patient position Baricity of the local anesthetic solution relative to patient position appears to be the most important factor in determining spread within the subarachnoid space.

Question 100

The effects of adding 1 mEq of sodium bicarbonate to 10 milliliters of local anesthetic solution include: - a decrease in the intensity of the block - an increase in pain at the injection site - a decrease in onset time - a decrease in duration of the block

Answer 100

a decrease in onset time Alkalinization of local anesthetic solutions speeds the onset and improves the quality of the block by increasing the amount of free base available. Interestingly, alkalinization also decreases pain during subcutaneous infiltration.

Question 101

In the figure below, the Mapleson D circuit is best represented by: (Make your selection by clicking on the appropriate part of the figure)

Answer 101

The Mapleson D circuit, shown below, is a non-rebreathing circuit. Carbon dioxide elimination is dependent on fresh gas flow. The circuit is much more efficient during controlled ventilation, requiring approximately 70 - 100 mL/kg/min of fresh gas flow for adequate carbon dioxide elimination. During spontaneous ventilation, 100 - 300 mL/kg/min is recommended.

Question 102

During a radical prostatectomy in a 68-year-old, occasional ventricular ectopy is noted and the following tracing from the pulmonary artery catheter is obtained. The most appropriate therapy would be: - administration of lidocaine 100 mg IV - advancement of the pulmonary artery catheter - 25% increase in tidal volume - increase anesthetic depth

Answer 102

advancement of the pulmonary artery catheter This trace shows a diastolic pressure of zero suggesting that the tip of the PA catheter is in the right ventricle. The ectopy implies that the catheter tip is causing RV wall irritation. The most appropriate therapy would be to properly locate the catheter by advancement.

Question 103

A 17-year-old female is scheduled for a nasal septoplasty under general anesthesia. She has no significant past medical history. Appropriate preoperative testing would include: - hemoglobin and hematocrit - glucose and electrolytes - chest xray - no preop testing required

Answer 103

no preoperative testing is required No preoperative testing is required. Preoperative pregnancy testing remains a subject of controversy with current practice varying among practitioners and centers.

Question 104

Despite the proper function of the fail-safe valve and oxygen proportioning system, a hypoxic mixture may be delivered if: - the wrong gas is in the oxygen pipeline - the pressure in the oxygen supply line falls below 25 psi - there is a leak in the oxygen supply line - there is a leak downstream from the fail-safe valve - helium is being administered as a third gas - oxygen flow exceeds minute ventilation

Answer 104

the wrong gas is in the oxygen pipeline, there is a leak downstream from the fail-safe valve, helium is being administered Circumstances under which the hypoxic guard systems can permit the formation of a hypoxic mixture include: wrong gas in the oxygen pipeline, defective pneumatics or mechanics, leaks downstream of the flow control devices and the administration of a third gas such as helium.

Question 105

Reduction in plasma concentration through non-specific blood and tissue esterases is seen with the use of: - fentanyl - alfentanil - remifentanil - sufentanil

Answer 105

remifentanil Unlike the other opioids, which depend on redistribution for the reduction of plasma concentration, remifentanil owes its very short half-life to rapid hydrolysis by tissue and plasma esterases.

Question 106

In the geriatric patient: - the dosage requirement of local anesthetic is reduced - the MAC of general anesthetics is increased - spinal anesthesia has a shorter duration of action - epidural anesthesia has a longer duration of action

Answer 106

the dosage requirement of local anesthetics is reduced Both the dosage requirements for local anesthetics and the MAC of general anesthetics are reduced in the elderly. Epidural anesthesia results in a greater cephalad spread but a shorter duration of action; spinal anesthetics have a longer duration of action.

Question 107

Within the anesthesia machine, nitrous oxide and oxygen are interfaced mechanically, pneumatically or electronically, so that the minimum oxygen concentration at the common gas outlet is approximately:

Answer 107

23 - 25% Manufacturers equip anesthesia workstations with N2O/O2-proportioning systems designed to prevent creation and delivery of a hypoxic mixture when nitrous oxide is administered. Nitrous oxide and oxygen are interfaced mechanically and/or pneumatically, or electronically (on the GE Aisys Carestation), so that the minimum oxygen concentration at the common gas outlet is between 23% and 25% depending on the manufacturer.

Question 108

Components of the intermediate-pressure system of the anesthesia machine include: - the yoke block with check valves - the cylinder pressure regulators - the flush valve - the flowmeter tubes

Answer 108

the flush valve Components of the intermediate-pressure system include the: pipeline inlets and gauges, ventilator power inlet, oxygen pressure-failure devices, flowmeter valve and the flush valve.

Question 109

After induction of a 73-year-old female scheduled for a right mastectomy, the rhythm below is noted. The patient's past medical history is significant only for insulin-dependent diabetes mellitus for the past 25 years. The most appropriate course of action at this time is: - administir digoxin 0.5 mg - cardioversion - postpone surgery and obtain a cardiac evaluation - adminstir verapamil to control heart rate

Answer 109

postpone surgery and obtain a cardiac evaluation The rhythm strip shows atrial fibrillation. New onset atrial fibrillation requires a search for the precipitating cause and often signifies an acute disease process or cardiac ischemia.

Question 110

Acute and life-threatening increases in serum potassium can be seen after succinylcholine administration in patients: (select 3) - with chronic renal failure - with extensive burns - with muscular dystrophy - that have received succinylcholine in the previous 10 minutes - with lower motor neuron disease - demonstrating a phase II block - with abnormal pseudocholinesterase

Answer 110

with extensive burns, with muscular dystrophy, with lower motor neuron disease Serum potassium increases 0.5 mEq/l from succinylcholine administration in normal individuals. However, patients with denervation injuries, such as burns, crush injuries and lower motor neuron diseases, can have exaggerated increases in serum potassium levels that can be life-threatening. Renal failure does not predispose to exaggerated increases in serum potassium. The diagnosis of muscular dystrophy is sometimes precipitated by a hyperkalemic event following succinylcholine administration.

Question 111

Upon the diagnosis of malignant hyperthermia, the following steps should be taken. By dragging & reordering the selections in yellow, place the steps in the correct order of implementation. - D/C Anesthetic - Hyperventilation with O2 - IV Dantrolene - Ice Lavage

Answer 111

Treatment of MH should be initiated with the discontinuation of all volatile anesthetics (and succinylcholine), followed by hyperventilation with oxygen. Intravenous administration of dantrolene should commence and be titrated to heart rate, ETCO2 and temperature. Active cooling and treatment of metabolic derangement should then be undertaken.

Question 112

Reactants involved in the absorption of CO2 by soda lime include: (select 3) - calcium hydroxide - calcium carbonate - water - sodium chloride - carbonic acid - hydrochloric acid

Answer 112

calcium hydroxide, water, carbonic acid The absorption of carbon dioxide by sodalime occurs in a 3-step reaction. Carbon dioxide combines with water to form carbonic acid. Carbonic acid reacts with sodium hydroxide to form sodium carbonate and water. Finally, calcium hydroxide reacts with sodium carbonate to produce calcium carbonate and regenerate sodium hydroxide.

Question 113

Therapeutic goals of the application of positive end-expiratory pressure to patients receiving mechanical ventilation are to: - increase lung water - achieve adequate PaO2 with an FiO2 of less than 0.5 - decrease functional residual capacity - increase closing capacity

Answer 113

achieve adequate PaO2 with an FiO2 of less than 0.5 The therapeutic goals of PEEP are to reduce lung water and improve oxygenation while lowering the FiO2. PEEP also increases FRC.

Question 114

A list of the oil:gas coefficients of the inhaled agents is shown below. By dragging & reordering the selections in yellow, match the inhaled agent with its corresponding oil:gas coefficient. - Nitrous Oxide - Desflurane - Sevoflurane - Isoflurane - 1.4 - 91 - 47 - 19

Answer 114

Nitrous Oxide-1.4 Desflurane-19 Sevoflurane-47 Isoflurane-91 The oil:gas coefficient correlates directly with the potency and inversely with the MAC of the inhaled agent. Therefore, the agents with the lowest MAC have the highest oil:gas coefficients.

Question 115

Laryngoscopy and oral endotracheal intubation: - reliably prevent gastric aspiration - reduce anatomic dead space by 50% - cause stimulation of cranial nerve IX resulting in bradycardia - are contraindicated in the patient with a CSF leak due to head trauma

Answer 115

reduce anatomic dead space by 50% Endotracheal intubation reduces anatomic dead space by 50%. Although endotracheal intubation helps to prevent gastric aspiration, it is not absolutely guaranteed. Bradycardia during laryngoscopy is a result of stimulation of cranial nerve X. Nasal intubation is contraindicated in the patient with CSF leak 2o head trauma.

Question 116

Perioperative hypothermia predisposes patients to:(select 2) - decreased metabolic rate - impaired coagulation - decreased cardiac work - decreased cutaneous blood flow - decreased incidence of postoperative wound infection

Answer 116

impaired coagulation, decreased cutaneous blood flow Perioperative hypothermia predisposes the patient to increased metabolic rate from shivering as well as increased cardiac work and increased rates of wound infection. Cutaneous blood flow is decreased as a result of vasoconstriction and redirection of blood flow away from the skin. Impaired coagulation has also been demonstrated in hypothermic patients.

Question 117

The most sensitive monitor for the detection of venous air embolism is the: - detection of end-tidal nitrogen - transesophageal echocardiogram - pulmonary artery catheter - end tidal CO2 monitor

Answer 117

transesophageal echocardiogram Monitors for the detection of venous air embolization in order of decreasing sensitivity are: TEE, Doppler, PA catheter, end-tidal carbon dioxide, and end-tidal nitrogen.

Question 118

Antibiotics associated with an increase in nondepolarizing neuromuscular blockade include: - cephalosporins - neomycin - penicillin - erythromycin

Answer 118

neomycin Aminoglycosides, polymyxins and lincosamides (clindamycin & lincomycin) are all associated with increasing the depth of neuromuscular blockade.

Question 119

Compensatory mechanisms that increase oxygen delivery in patients with chronic anemia include: - decreased RBC 2,3-diphosphoglycerate - decreased P50 - decreased plasma volume - decreased blood viscosity

Answer 119

decreased blood viscosity Cardiac output, 2,3-DPG levels, P-50, and plasma volume are all increased to improve tissue oxygen delivery. However, plasma viscosity is decreased and this allows for a further increase in cardiac output and blood flow.

Question 120

Anesthetic agents that should be avoided in patients receiving intravitreal sulfur hexafluoride for mechanical support of the retina include: - isoflurane - sevoflurane - desflurane - nitrous oxide

Answer 120

nitrous oxide Intraocular sulfur hexafluoride is used to support the retina in cases of retinal detachment. Because of its solubility, nitrous oxide may significantly increase the size/pressure of the bubble and should be avoided.

Question 121

Kyphoplasty: - requires a large surgical incision with the patient in the prone position - is intended to improve the strength of the vertebral body - is used in the treatment of the piriformis syndrome - is effective in relieving the symptoms of thoracic outlet syndrome

Answer 121

is intended to improve the strength of the vertebral body Kyphoplasty and vertebroplasty lead to restoration of some of the decreased vertebral height, improve strength of the vertebral body, and decrease stress placed on the adjacent vertebrae in patients with vertebral compression fractures. Kyphoplasty differs from vertebroplasty in that kyphoplasty involves the percutaneous introduction of a balloon into the vertebral body, inflation of the balloon, then filling the balloon with methacrylate cement that is more viscous than that used for vertebroplasty.

Question 122

In an adult patient, nasal cannula with an oxygen flow rate of 6 L/min will produce an FiO2 of approximately:

Answer 122

``` 39 - 44% Nasal cannula produce FiO2 ranges based upon oxygen flow rates, nasopharyngeal volume, and the patient's inspiratory flow rate. Approximations of the FiO2 are: 1 L/min - 0.21-0.24 2 L/min - 0.23-0.28 3 L/min - 0.27-0.34 4 L/min - 0.31-0.38 5-6 L/min - 0.39-0.44 ```

Question 123

According to the ASA's Difficult Airway Algorithm, the initial appropriate maneuver in the "can't intubate/can't ventilate" scenario after induction of general anesthesia is: - secure an immediate surgical airway - laryngoscopy by alternate caregiver - consider/attempt LMA - administer additional neuromuscular blockade

Answer 123

consider/attempt LMA If initial attempts at intubation are unsuccessful and face mask ventilation is inadequate, consider/attempt an LMA is the next maneuver on the ASA's Difficult Airway Algorithm.

Question 124

The cerebral metabolic rate of oxygen consumption may be increased by the use of: - midazolam - ketamine - etomidate - propofol

Answer 124

ketamine Ketamine has been shown to increase the CMRO2. Reductions in CMRO2 can be achieved with barbiturates, desflurane and isoflurane, all of which can produce a profound reduction in cerebral electrical activity.

Question 125

A small percentage of blood normally bypasses the right ventricle and empties directly into the left atrium, accounting for physiologic shunting. The percentage of cardiac output that is made of this venous drainage is approximately:

Answer 125

2 - 5% Venous return from the pleural, bronchial and Thebesian veins bypasses the right ventricle and empties into the left atrium causing normal physiologic shunt. This accounts for 2 - 5% of the total cardiac output.