The Effects of Postural Change on Hemodynamics / 대한마취과학회지

The purpose of this study was to evaluate the effect of postural change on hemodynamics under halothane-N2O-O2 anesthesia. The authors measured heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), mean pulmonary artery pressure (PVP), and cardiac index (C1) on supine position (baseline), and after a postural change to the lithotomy, head up tilt (5, 10, 15 degress) and head down tilt (5, 10, 15 degrees) positions in 10 healthy subjects. The results were as follows: 1) After a postural change to the lithotomy position, all hemodynamic variables revealed no changes. 2) After a change to the head up position, MAP, CVP, PAP, PCWP, and CI decreased significantly, while HR remained unchanged. 3) After a change to the head down position, CVP, PAP, PCWP, and CI increased and HR decreased significantly, while MAP remained unchanged. From the above results, it might be concluded that a down ward tilt of 10 degrees is most the appropriate position to restore hemodynamics in the presence of cardiovascular instability.

Influence of Nitroglycerin on the Heart Rate and Blood Pressure Increased by Ketamine / 대한마취과학회지

Ketamine produces an increase in the heart rate and blood pressure, but the precise mechanism is controversial. In order to obtain inslight into the mechanism by observing the influence of nitroglycerin (NTG) on the ketamine effect, ketamine was administered intravenously following sublingual administration of nitroglycerin in conscious patients. The results were as follows: 1) In the ketamine(2mg/kg) group(n=15), the heart rate and blood pressure increased significantly by as much as 25%. 2) In the nitroglycerin(1.2mg) group(n=12), the heart rate increased, but blood pressure decreased from 5 minutes after administration. 3) In the group which received ketamine(2mg/kg) 5min. after NTG(1.2mg)(N=15), the heart rate did not change, but the blood pressure increased significantly without attenuation by nitroglycerin. From the above results, it is suggested that in the ketamine effect control mechanism may also be participated in addition ot the peripheral mechanism involving norepinephrine release.