A 65-kg, 57-year-old man has an initial activated clotting time (ACT) of 122 seconds prior to elective cardiopulmonary bypass. Five minutes after administration of heparin 200 mg, ACT increases to 154 seconds. After two additional doses of 200 mg each from different lots, ACT increases to 240 seconds. The most appropriate next step is to
During carotid endarterectomy, blood pressure suddenly decreases from 140/90 to 80/50 mmHg. The EKG shows a heart rate of 42 bpm, with normal sinus rhythm and occasional premature ventricular contractions. The most appropriate therapy is intravenous administration of
(A) atropine
(B) epinephrine
(C) isoproterenol
(D) lidocaine
(E) phenylephrine
A
A 55-year-old patient with hypertrophic cardiomyopathy (IHSS) is undergoing bladder suspension with enflurane 1%, nitrous oxide 50%, and oxygen 50%. Junctional tachycardia and hypotension develop suddenly immediately after skin incision. The most appropriate management is to
(A) decrease enflurane concentration
(B) administer an intravenous fluid bolus
(C) administer intravenous esmolol
(D) administer intravenous phenylephrine
(E) begin nitroglycerin infusion
C
Compared with adults, neonates are more likely to become hypoxemic following anesthesia and extubation because of a relatively
Which of the following is most likely to occur during deliberate hypotension with trimethaphan?
(A) Bronchoconstriction
(B) Cerebral vasodilation
(C) Increased heart rate
(D) Potentiation of pancuronium
(E) Pupillary constriction
C
Which of the following provides the earliest indication of myocardial ischemia during general anesthesia?
(A) Cardiac index
(B) Mixed venous oxygen saturation
(C) Pulmonary artery occlusion pressure
(D) Regional ventricular wall motion
(E) ST-segment depression on ECG
D
A 45-year-old woman undergoes aortic valve replacement for aortic stenosis. Two minutes after removal of the venous cannulae, air is noted in the arterial inflow cannula. Heart rate is 80 bpm, blood pressure is 95/60 mmHg, and cardiac index is 1.5 L/min/m2. ST-segment elevation is noted in EKG leads II, III, and aVF. The most appropriate next step is to
(A) administer thiopental
(B) decrease left ventricular afterload
(C) increase arterial blood pressure
(D) replace the left ventricular vent
(E) resume cardiopulmonary bypass
C
Which of the following would be most likely to result in neonatal depression when administered to a healthy parturient during an uncomplicated labor and vaginal delivery?
(A) Nitrous oxide 60% in oxygen supplemented with halothane 0.5% for 10 minutes before delivery
(B) Ketamine 20 mg intravenously 30 minutes before delivery
(C) Meperidine 100 mg intramuscularly 2 hours before delivery
(D) Thiopental 100 mg intravenously 30 minutes before delivery
(E) Nitrous oxide 60% in oxygen supplemented with enflurane 0.7% for 10 minutes before delivery