10 Random Questions
The most common transfusion-related infection is
- (A) bacterial sepsis
- (B) cytomegalovirus infection
- (C) hepatitis B
- (D) hepatitis C (non-A, non-B)
- (E) human immunodeficiency virus infection
Compared with the demand-flow intermittent mandatory ventilation (IMV) system, the continuous-flow IMV system has which of the following characteristics?
- (A) It cannot be used with positive end-expiratory pressure
- (B) It permits monitoring of exhaled tidal volume
- (C) It decreases waste of medical gases
- (D) It decreases the work of breathing
- (E) It synchronizes mechanical and spontaneous breaths
In a patient with 20% pulmonary shunt and a PaO2 of 60 mmHg, cardiac output suddenly decreases from 5 L/min to 3 L/min. Oxygen consumption is unchanged. As a result, the PaO2 will
- (A) increase slightly because of decreased shunt blood flow
- (B) decrease slightly because of decreased mixed venous PO2
- (C) increase because of decreased affinity of hemoglobin for oxygen
- (D) decrease because of an increased dead space to tidal volume ratio
- (E) increase because of increased pulmonary oxygen uptake per milliliter of blood
Compared with epidural morphine, intrathecal morphine produces
- (A) better relief of visceral pain
- (B) greater loss of analgesia after administration of naloxone
- (C) less pruritus
- (D) less urinary retention
- (E) more respiratory depression
In an anesthetized patient being mechanically ventilated, end-expired carbon dioxide is 58 mmHg and peak inspiratory airway pressure is 15 cmH20. Ventilator settings indicate a delivered tidal volume of 800 ml, but the expiratory flowmeter shows a tidal volume of 360 ml. Which of the following is the most likely cause of this discrepancy?
- (A) Fresh gas flow of 0.5 L/min
- (B) Incompetence of the pressure-relief valve
- (C) Low ventilatory rate
- (D) Presence of a hole in the ventilator bellows
- (E) Prolongation of the inspiratory phase
Which of the following is characteristic of soda lime and Baralyme carbon dioxide absorption canisters used in circle systems?
- (A) Calcium carbonate is a major end product
- (B) Carbon dioxide absorption cools the anesthetic gases
- (C) Flushing the canister with oxygen for six hours will regenerate 50% of the spent Baralyme
- (D) Gases lose water vapor as they pass through the canisters
- (E) Soda lime and Baralyme depend on silica as a binding agent
The most sensitive means of detecting venous air embolism is
- (A) precordial Doppler stethoscope
- (B) transesophageal echocardiography
- (C) end-tidal carbon dioxide measurement
- (D) pulmonary artery pressure measurement
- (E) central venous pressure measurement
Which of the following additives accelerates the onset of lidocaine axillary block without shortening duration?
- (A) Carbon dioxide
- (B) Dextran
- (C) Dextrose
- (D) Epinephrine
- (E) Hyaluronidase
A 65-year-old man with essential hypertension well controlled around 140/90 mmHg with hydrochlorothiazide is scheduled for right colectomy for carcinoma. Preoperative EKG and all laboratory values are normal except for a hematocrit of 29% and serum potassium level of 3.2 mEq/L. Central venous pressure (CVP) measured from an internal jugular catheter inserted before induction of anesthesia is 7 mmHg. Ten minutes after induction with thiopental 200 mg followed by enflurane 3% in nitrous oxide and oxygen (50% each), blood pressure decreases suddenly from 110/70 to 80/50 mmHg with heart rate unchanged at 78 bpm. CVP is now 20 mmHg and the EKG demonstrates a midjunctional rhythm. After discontinuing the enflurane, the most appropriate action would be to
- (A) administer furosemide 20 mg intravenously
- (B) verify proper placement of the CVP catheter
- (C) administer atropine 0.4 mg intravenously
- (D) administer packed erythrocytes 1 unit
- (E) administer potassium 20 mEq in 250 ml of intravenous fluid over 15 minutes
The plasma concentration of an intravenously administered drug follows the two-compartment kinetic model shown in the graph. Which of the following events is illustrated by the decline in plasma concentration shown at Time #2?
- (A) Decreasing activity of the drug at its receptor site
- (B) Distribution from plasma to tissue
- (C) Elimination of the drug from plasma
- (D) Increasing volume of distribution
- (E) Redistribution from vessel-rich groups to vessel-poor groups