A 70-kg 22-year-old patient with head trauma and multiple fractures of the long bones is scheduled for fixation of bilateral femoral fractures. Preoperative laboratory studies show a serum sodium concentration of 150 mEq/L, a serum potassium concentration of 3.1 mEq/L, and a urine output greater than 500 ml/hr. Which of the following agents will decrease urine output?
Following pneumonectomy, a paralyzed patient being mechanically ventilated has the following arterial blood gas values: PaO2 71 mmHg, PaCO2 55 mmHg, pH 7.29. SvO2 is 45%. The most likely explanation for this SvO2 is
Addition of 20 cm H2O positive end-expiratory pressure to a patient receiving controlled mechanical ventilation decreases cardiac output and left ventricular function by
A patient is undergoing exploration of a stab wound to the left side of the neck. On awake laryngoscopy, the left vocal cord is in midposition and the right vocal cord is abducted during inspiration. The most likely cause of these findings is trauma to which of the following structures on the left?
A 26-year-old woman comes to a pain clinic because of pain, swelling and limitation of motion in the right knee for six months following a blow to the knee. Findings on knee arthroscopy and leg roentgenograms are normal. The best trial of therapy is
(A) right paravertebral lumbar sympathetic nerve block
(B) epidural administration of a steroid
(C) intrathecal administration of an opioid
(D) tricyclic antidepressants for one month
(E) a nonsteroidal anti-inflammatory drug for five days