Salerno T A, Milne B, Jhamandas K H
Surg Gynecol Obstet. 1981 Jun;152(6):773-6.
The narcotic antagonist naloxone has been shown to reverse hypotension in hemorrhagic and septic shock in rats and dogs. This study was undertaken to investigate the hemodynamic effects of naloxone on hemorrhagic shock in the pig. Thirteen pigs were anesthetized with pentobarbital and were bled to a mean arterial pressure of 54 per cent of the initial mean arterial pressure. Seven pigs received naloxone in increasing doses of 1.0, 2.5 and 5.0 milligram per kilogram intravenously, while the six pigs in the control group were given identical volumes of normal saline solution. Results indicate an increase in mean arterial pressure in the pigs of the naloxone group compared with that for the pigs in the saline solution treated group. There was no increase in cardiac output after the administration of naloxone or after the injections of saline solution. Peripheral vascular resistance increased in pigs in the naloxone group compared with that in pigs in the saline solution group. These results are in accordance with the concept that naloxone may reverse hypotension in hemorrhagic shock by antagonizing endogenous opiate-like substances and that the latter may be involved in the physiopathology of shock. The rapid increase in peripheral vascular resistance after the administration of naloxone suggests a change in sympathetic reflex as a possible mechanism of naloxone action.
麻醉拮抗剂纳洛酮已被证明可逆转大鼠和狗在出血性休克和感染性休克中的低血压状态。本研究旨在探讨纳洛酮对猪出血性休克的血流动力学影响。13只猪用戊巴比妥麻醉，放血使平均动脉压降至初始平均动脉压的54%。7只猪静脉注射递增剂量（每千克体重1.0、2.5和5.0毫克）的纳洛酮，而对照组的6只猪则给予相同体积的生理盐水。结果表明，与生理盐水处理组的猪相比，纳洛酮组猪的平均动脉压有所升高。注射纳洛酮或生理盐水后心输出量均未增加。与生理盐水组的猪相比，纳洛酮组猪的外周血管阻力增加。这些结果符合以下观点：纳洛酮可能通过拮抗内源性阿片样物质来逆转出血性休克中的低血压，且后者可能参与休克的病理生理过程。纳洛酮给药后外周血管阻力迅速增加，提示交感反射改变可能是纳洛酮作用的一种机制。
