Mepivacaine 40 ml of a 1% solution with epinephrine 1:200,000 is injected into the brachial plexus sheath at the axilla after eliciting a paresthesia in the ulnar nerve distribution. Which of the following is most likely to remain intact?
(A) Adduction of the thumb
(B) Flexion at the wrist
(C) Sensation of the lateral forearm
(D) Sensation on the palmar surface of the lateral three and one half fingers
(E) Sensation on the palmar surface of the medial one and one half fingers
After a gastric stapling procedure, a 150-kg woman is extubated and breathing spontaneously in the recovery room at a rate of 26/min and an FiO2 of 0.5. Arterial blood gas analysis shows PaO2 96 mmHg, PaCO2 44 mmHg, and pH 7.37. The parameter most closely related to her increased alveolar-arterial oxygen tension gradient is
A 15-kg, 3-year-old child is anesthetized for an inguinal hernia repair with halothane and nitrous oxide. The trachea is intubated after administration of succinylcholine 30 mg. At the conclusion of the 45-minute procedure, the child is not breathing; a peripheral nerve twitch monitor indicates no response to a train-of-four stimulus. Further investigation is most likely to show
(A) abnormal response to nondepolarizing muscle relaxants
(B) a low dibucaine number
(C) a low plasma cholinesterase concentration
(D) an underlying myopathy
(E) a positive halothane-caffeine contracture test
Which of the following is the most common infection transmitted through transfusion of blood products?
(A) Epstein-Barr virus
(B) Hepatitis B
(C) Hepatitis C
(D) Human immunodeficiency virus
(E) Toxoplasmosis
B
A 46-year-old patient who abuses intravenous drugs develops acute aortic valvular insufficiency from bacterial endocarditis. Which of the following statements concerning pressures measured through a pulmonary artery catheter is true?
(A) Pulmonary artery occlusion pressure will underestimate left ventricular end-diastolic pressure
The central anticholinergic syndrome is LEAST likely to occur after administration of
(A) atropine
(B) chlorpromazine
(C) diphenhydramine
(D) glycopyrrolate
(E) scopolamine
D
Which of the following attenuates the most common cardiovascular side effect of protamine administration?
(A) Pretreatment with a diuretic
(B) Pretreatment with a prostaglandin inhibitor
(C) Pretreatment with a pulmonary vasodilator
(D) Injection via the distal lumen of the pulmonary artery catheter
(E) Slow peripheral intravenous injection
E
Following pneumonectomy, a paralyzed patient being mechanically ventilated has the following arterial blood gas values: PaO2 71 mmHg, PaCO2 55 mmHg, pH 7.29. SvO2 is 45%. The most likely explanation for this SvO2 is