A 30-year-old, 70-kg woman with mitral stenosis is scheduled for elective laparoscopic sterilization. Preoperatively she is taking digoxin and an unknown medication for chronic mental depression. The EKG demonstrates atrial fibrillation. Heart rate is 68 bpm. Anesthesia is induced with thiopental followed by nitrous oxide 50%, halothane 0.75%, and a continuous succinylcholine infusion. The ventilator is set to deliver a minute volume of 5 liters through an endotracheal tube. As the carbon dioxide is being insufflated into the abdomen, the blood pressure is noted to be elevated (150/100 mmHg) and ventricular bigeminy is present. The most appropriate therapy is to
(A) increase the halothane concentration to 1.25%
(B) discontinue the succinylcholine infusion
(C) increase minute ventilation to 7.5 L/min
(D) administer potassium 5 mEq intravenously over one minute followed by propranolol 0.25 mg
(E) measure arterial blood gas and serum electrolyte values
In the PACU after resection of an occipital astrocytoma, a patient has a urine output greater than 300 ml/hr, serum osmolality of 310 mOsm/L, and a hematocrit of 40% (equal to the preoperative value). Intraoperative blood loss was estimated to be 750 ml; furosemide and mannitol were administered during the procedure. The most appropriate next step is
(A) restriction of free water
(B) administration of 0.9% saline solution
(C) administration of desmopressin
(D) administration of dexamethasone
(E) CT scan of the brain
B
A single dose of etomidate for induction of anesthesia will cause
One hundred children who are to have strabismus surgery are enrolled in a research protocol. Fifty receive a new antiemetic and 50 receive a placebo preoperatively. Fifteen children in the treatment group and 37 children in the control group have nausea and vomiting postoperatively. Which of the following analyses is most appropriate for determining the statistical significance of the group differences?