Masui. The Japanese journal of anesthesiology
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We determined both the slope of the left ventricular end-systolic pressure-volume relation (Emax), which is a measure of contractility independent of loading conditions, and the slope of the arterial end-systolic pressure-stroke volume relation (Ea), which is a measure of arterial load independent of ventricular function, in 10 patients undergoing elective noncardiac surgery. Left ventricular end-systolic volume (Ves) was measured by transesophageal echocardiography and instantaneous left ventricular end-systolic pressure (Pes) was estimated from the dicrotic notch pressure in the radial artery. Emax was calculated during afterload reduction (nicardipine 30 micrograms.kg-1 iv), and the correlation of Emax to either Pes/Ves ratio or MAP (mean arterial blood pressure)/Ves ratio was accomplished in order to investigate whether these indices were clinically useful measurements of ventricular function or not. ⋯ Ea decreased significantly (P < 0.05) following intravenous nicardipine, demonstrating a decreased arterial load. The direction of changes in Ea was similar to that reported previously in systemic vascular resistance. From these results, we conclude that measurement of Emax (or Pes/Ves, MAP/Ves) and Ea using transesophageal echocardiography and radial artery pressure tracing is feasible and these are a useful tool to estimate left ventricular performance and arterial load during surgery.
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Postoperative analgesia with epidurally injected buprenorphine and its side effects were investigated in 100 patients who had received lower abdominal surgery. All patients received initially 8 ml of bupivacaine and 0.1 mg of buprenorphine. ⋯ No significant difference in the incidence of side-effect was found among groups C, D, E. We conclude that a dose of a approximately 15 micrograms.h-1 might be optimal for postoperative pain relief after lower abdominal surgery.