[Clinical effects of naloxone on hemorrhagic shock]

In order to study the clinical effects of naloxone on hemorrhagic shock, 21 patients with moderate hemorrhagic shock were randomly divided into two groups. The naloxone group (NLX group) was infused normal saline (200ml) and naloxone (0.02mg/kg) via central vein while the control group was infused normal saline (200ml) only. Mean arterial pressure (MAP), central vein pressure (CVP), cardiac output (CO), cardiac index (CI), peripheral vascular resistance (PVR), levels of lactic acid in both artery and vein, and levels of catecholamine in artery were measured before and after the administration of naloxone or normal saline. The results showed that naloxone significantly increased blood level of catecholamine and MAP (P < 0.01), the effects sustained for more than 15 minutes with an increased PVR (P < 0.05). After infustion of normal saline, blood level of lactic acid in artery and vein decreased slightly (P > 0.05), yet comparatively lower in artery. On the contrary, after administration of naloxone, the blood level of lactic acid markedly decreased in both artery and vein (P < 0.01), but higher in artery. It is suggested that naloxone improve tissue oxygen supply temporarily with enhancement of tissue lactic acid metabolism.