A 40-year-old man is undergoing open reduction and internal fixation of a fractured femur. During anesthesia with fentanyl, sevoflurane, and oxygen, heart rate decreases to 20 bpm and 6 premature ventricular contractions per minute are noted. No pulse is detected. The most appropriate next step is to
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
A 65-year-old man undergoes prostatectomy in the lithotomy position under spinal anesthesia using bupivacaine 12 mg. Ten hours later, he reports that his left foot is numb. Examination shows decreased pinprick sensation over the lateral dorsal aspect of the left foot; dorsiflexion is limited. Which of the following is the most likely cause?
A full-term newborn has marked respiratory distress in the delivery room. Breath sounds are asymmetric and the abdomen is scaphoid. Which of the following maneuvers is most appropriate?
(A) Hyperventilation with bag and mask
(B) Intubation and ventilation with positive end-expiratory pressure
(C) Intubation and ventilation with zero end-expiratory pressure