Development and Use of a Swine Model for Evaluating Anesthetic Agents and Devices

Abstract : Ketamine has been advocated for the induction of anesthesia in the acutely hypovolemic patient because of its ability to preserve blood pressure which is mediated by catecholamine induced vasoconstriction. Thiopental causes a decrease in blood pressure and vasodilation, which are exacerbated during hypovolemia, The effects of anesthetic induction doses of Ketamine and thiopental were evaluated in a hypovolemic swine model. Sixteen acutely instrumented swine were mechanically ventilated with N2) (70%) and O2 (30%) and hemorrhaged to a mean arterial blood pressure of 40mm Hg. After 15 minutes of stabilization, ketamine (6 mg/kg) or thiopental (6 mg/kg) was administered as a intravenous bolus to simulate the induction of anesthesia. Hemodynamic measurements from a pulmonary artery catheter were made at baseline and hemorrhage states, and 1, 5, 15, and 30 minutes after drug administration. Cardiodynamics consisting of myocardial contractility (Ees) and left ventricular function were assessed from the end-systolic pressure-dimension relationship (ESPDR) and pressure-dimension (PD) loops respectively. (js)