THE EFFECTS OF DESFLURANE ON CARDIAC-FUNCTION AS MEASURED BY CONDUCTANCE VOLUMETRY IN SWINE

The purpose of the investigation was to assess the effects of desflura ne (DES) on left ventricular heart function during basal barbiturate a nesthesia in a closed-pericardium, closed-chest acute swine model. The study was performed in 11 normoventilated adult pigs. Hemodynamic mea surements were obtained using arterial,central venous, and pulmonary a rtery catheters, as well as a conductance volumetry and tip manometry catheter placed in the left ventricle. Hemodynamic measurements were r ecorded during basal pentobarbital anesthesia and with the addition of 1%, 2%, 4%, and 6% DES. DES dose-dependently decreased mean arterial pressure, systemic vascular resistance, left ventricular end-systolic pressure, dP/dt(MAX) and dP/dt(MIN). At doses >1%, decreases in CO, st roke volume, ejection fraction, end-systolic elastance, preload recrui table stroke work, preload adjusted maximal power, and peak filling ra te were observed. Heart rate decreased at 4% and 6% DES. Isovolumetric relaxation time increased only at 6% DES. We conclude that smaller do ses of DES have a significant cardiodepressive effect in the setting o f barbiturate infusion, as measured by conductance volumetry. Implicat ions: Desflurane, in very small doses, depressed cardiac function duri ng pentobarbital anesthesia with ketamine and benzodiazepine pre medic ation in swine, as assessed by conductance volumetry and left ventricu lar pressure and volume relationship analysis. These results suggest t hat desflurane, in combination with certain anesthetics, can be cardio depressive even in very small doses.