Four hours after open cholecystectomy, a patient who is breathing spontaneously has an SpO2 of 93% in the supine position and an SpO2 of 98% when placed in the head-up position. The most likely cause of this change is an increase in which of the following?
A 27-year-old man with chronic renal failure is to undergo revision of an arteriovenous graft. He insists on general anesthesia. Hemodialysis was completed two hours ago, and serum potassium concentration is now 5 mEq/L. Which of the following statements concerning anesthetic management of this patient is true?
(A) Enflurane is contraindicated
(B) Succinylcholine is contraindicated
(C) Neostigmine will be required in larger than usual dosage
(D) The duration of action of atracurium will be prolonged
(E) The duration of action of propofol will be unchanged
E
If minute ventilation remains constant, a decrease in end-expiratory carbon dioxide concentration will occur with
An axillary block is administered to a 60-kg patient using 40 ml of 0.5% bupivacaine. Ten minutes after placement of the block, the patient has a seizure. Which of the following statements is true?
(A) A low serum albumin concentration could have contributed to the occurrence of the seizure
(B) CNS hypoperfusion is the most likely cause of the seizure
(C) The seizure was probably secondary to an allergic reaction to the local anesthetic
(D) The use of an equipotent dose of lidocaine rather than bupivacaine would have decreased the likelihood of
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
A 62-year-old man is undergoing elective coronary artery bypass grafting and aortic valve replacement for three-vessel coronary artery disease and aortic stenosis. Shortly after intubation, heart rate increases from 75 to 100 bpm and blood pressure decreases from 130/70 to 70/40 mmHg with acute, severe ST-segment depression in lead V5. Which of the following is the most appropriate management?
A 58-year-old woman with rheumatoid arthritis and hyperactive gag reflex requires awake intubation prior to cervical spine stabilization. Which of the following regional nerve blocks is most appropriate?
An intubated patient is breathing spontaneously through the T-piece shown in Figure 1. Addition of tubing at A and B as shown in Figure 2 without an increase in minute ventilation will result in
(A) unchanged FiO2 and increased PaCO2
(B) unchanged FiO2 and unchanged PaCO2
(C) increased FiO2 and increased PaCO2
(D) increased FiO2 and unchanged PaCO2
(E) decreased FiO2 and increased PaCO2
C
The last muscle to be affected by an interscalene brachial plexus block is the