A patient suddenly makes a respiratory effort during craniotomy for clipping of a cerebral aneurysm in a 15-degree head-up position with controlled ventilation. The most likely cause is
A 64-year-old, 70-kg woman treated with lithium for manic-depressive psychosis is given methohexital 90 mg and succinylcholine 35 mg intravenously for electroconvulsive therapy. Ten minutes later she remains sedated and the peripheral nerve stimulator shows a decreased twitch response. The most likely explanation is
The following breath sounds are heard after placement of a left-sided double-lumen endobronchial tube.
The most likely cause of these findings is
(A) presence of both lumens in the right mainstem bronchus
(B) presence of both lumens in the left mainstem bronchus
(C) presence of both lumens in the trachea
(D) herniation of the bronchial cuff at the bifurcation of the trachea
(E) presence of the bronchial lumen in the right mainstem bronchus
C
Monitoring of a patient with a closed head injury shows the following pressures: Intracranial pressure 30 mmHg, Central venous pressure 5 mmHg, Mean arterial pressure 65 mmHg, Peak airway pressure 25 cmH,0. The cerebral perfusion pressure is
(A) 30 mmHg
(B) 35 mmHg
(C) 40 mmHg
(D) 60 mmHg
(E) 65 mmHg
B
The acute onset of hypotension without a decrease in mixed venous oxygen saturation is most likely associated with the onset of