Journal of anesthesia
-
Journal of anesthesia · Sep 1996
Effect of nicardipine on vascular capacitance: Comparison with sodium nitroprusside during induced hypotension.
The purpose of this study was to examine the effects of nicardipine and sodium nitroprusside (SNP) on vascular capacitance in the rat. In ten rats anesthetized with pentobarbital, mean arterial pressure was lowered to about 70 mmHg and subsequently 50 mmHg by intravenous infusion of nicardipine or SNP. Vascular capacitance was assessed before and during nicardipine- or SNP-induced hypotension by measuring the mean circulatory filling pressure (MCFP). ⋯ MCFP was significantly decreased by SNP from 7.1 ±0.3 mmHg at control to 5.6 ± 0.4 mmHg and 4.4 ± 0.3 mmHg at mean arterial pressures of 70 mmHg and 50 mmHg, respectively. However, MCFP stayed at a similar level to that of the control during nicardipine-induced hypotension. These results suggest that nicardipine has a negligible influence on vascular capacitance during induced hypotension, whereas SNP has a potent vasodilating effect on the venous system as well as the arterial system.
-
Journal of anesthesia · Sep 1996
Flumazenil does not antagonize the cardiac effects of midazolam in the isolated rat heart-lung preparation.
We examined the effects of midazolam and flumazenil on cardiac function and metabolism in the isolated rat heart-lung preparation. Wistar rats were divided into five groups (each group:n=8) as follows: (1) control (saline); (2) flumazenil (1.3×10(-5)M); (3) flumazenil (10(-4)M); (4) midazolam (60μg·ml(-1)); and (5) midazolam (60μg·ml(-1)) and flumazenil (1.3×10(-5)M). Systolic blood pressure and calculated left ventricular dP/dt maximum in the midazolam or midazolam conbined with flumazenil groups increased significantly in comparison with those in the control group. ⋯ There were no significant differences in the myocardial tissue concentration of ATP, lactate, and glycogen in all groups. In this study, midazolam decreased heart rate; however, flumazenil had no effect on the heart, nor did it antagonize the cardiac effects of midazolam. These results suggest that flumazenil has no effect on the peripheraltype benzodiazepine receptor of the myocardium.
-
Journal of anesthesia · Sep 1996
Hypertonic saline for intraoperative fluid therapy in transurethral resection of the prostate.
We tested hypertonic saline solution (HS) to determine its effectiveness in surgical procedures for prostatic hypertrophy. We randomly selected 40 patients undergoing elective transurethral resection of the prostate for either infusion of HS (3% NaCl) at 4ml·kg(-1)·min(-1) (HS group) or lactated Ringer's solution (LR) at 8 ml·kg(-1)·min(-1) (LR group). Anesthesiologists regulated the intraoperative infusion rate as needed to maintain blood pressure. ⋯ An osmolar gap exceeding 10mOsm·kg(-1) was observed in 2 patients in the HS group, but plasma sodium remained at normal values. However, in the 1 patient in the LR group whose osmolar gap exceeded 10mOsm·kg(-1), plasma sodium was 115 mEq·I(-1). HS, at a low dose, is useful in the intraoperative management of transurethral resection of the prostate.