The Evaluation of Hypoxic and Hypercapnic Ventilatory Depression Induced by Narcotic and Non-narcotic Analgesics

循环和呼吸系统对缺氧或高碳酸血症的反应被认为是维持生命的代偿反应。但有时，缺氧或高碳酸血症会引起一些患者严重的呼吸抑制。因此，我们评价了麻醉性镇痛药和非麻醉性镇痛药对低氧或高碳酸血症通气抑制的影响。实验选用5只体重为2.2kg ~ 2.7kg的家兔。兔用戊巴比妥50mg/kg静脉麻醉。气管造口后，动物插管，机械通气50%氧，50%氮，1-2%氟烷。将激光流量计和组织氧饱和度监测仪两个小传感器附着在动物侧小剖腹手术后的膈肌表面。在自主呼吸、控制通气和吸气阻力负荷下测量膈血流量和膈组织血氧饱和度。测量完成后，计算膈肌耗氧量（Vo_2di）。对得到的Vo_2di进行跟踪；自主呼吸：2.08 ml/min/100g，控制通气：1.98 ml/min/100g，吸气阻力负荷：2.87 ml/min/100g。因此，吸入阻力负荷下的Vo_2di高于其他负荷。综上所述，我们通过测量组织氧饱和度和组织血流量来评价组织氧代谢的方法有助于分析镇痛药或镇痛方法对低氧和高碳酸血症通气和循环反应的影响。

Circulatory and respiratory responses to hypoxia or hypercapnia are thought to be compenstory responses to support life. But on occasion, hypoxia or hypercapnia induce severe respiratory depression in some patients. Therefore we evaluated the effect on hypoxic or hypercapnic ventilatory depression of narcotic and non-narcotic analgesics. Experiments was performed on 5 rabbits weighing 2.2kg to 2.7kg. Rabbits were anesthetized with pentobarbital 50mg/kg intravenously. After tracheostomy, animals were intubated and mechanically ventilated with 50% oxygen, 50% nitrogen, and 1-2% halothane. Two small sensors of laser flow meter and tissue oxygen saturation monitor were attached on diaphragma muscle surface of the animals after lateral small laparotomy. Diaphragmatic blood flow and diaphragmatic tissue oxygen saturation were measured under spontaneous respiration, controlled ventilation and inspiratory resistive loading. After the measurement was performed diaphragmatic oxygen consumption (Vo_2di) were computed. Obtained Vo_2di were followed ; spontaneous respiration : 2.08 ml/min/100g, controlled ventilation : 1.98 ml/min/100g, inspiratory resistive loading : 2.87 ml/min/100g. Consequently, Vo_2di under inspiratory resistive loading showed higher than the others. Above them, we concluded that our method evaluating the tissue oxygen metabolism by measuring both the tissue oxygen saturation and tissue blood flow was useful to analyze the effect of the analgesics or the analgesic method on hypoxic and hypercapnic ventilatory and circulatory responses.