A multi-orifices right heart catheter is being positioned by EKG control prior to sitting craniotomy. The EKG tracing is obtained between the distal tip of the catheter and the right arm lead. The most appropriate next step is to
For 30 minutes, a patient has been receiving oxygen 2 L, nitrous oxide 2 L, and halothane from an agent-specific vaporizer set at 1%. A mass spectrometer sampling gas from the patient's airway shows an end-tidal halothane concentration of 0.7%. The most likely explanation for this difference is
A healthy 57-year-old man with a ureteral calculus is scheduled for immersion extracorporeal shock wave lithotripsy. Which of the following statements is true?
(A) Delivery of the shock wave is timed by the R wave of the ECG
(B) Continuous epidural anesthesia is contraindicated because of the risk for infection
(C) If a regional technique is used, a T10 sensory level is required for adequate anesthesia
(D) If general anesthesia is used, high tidal volumes and low respiratory rate are preferred
(E) Removal of the patient from the bath is accompanied by an increase in blood pressure
A 34-year-old man has hyperkalemia-induced asystole. After initiating cardiopulmonary resuscitation, which of the following is the most appropriate next step in management?
(A) Administration of atropine
(B) Administration of calcium chloride
(C) Administration of sodium bicarbonate
(D) Transcutaneous pacing
(E) DC countershock at 200 joules
B
A man with alcoholic cirrhosis and a hemoglobin concentration of 10 g/dl has an intraoperative PaO2 of 75 mmHg at an FiO2 of 0.5. Which of the following is the most likely cause of the low PaO2?