Gauthier R A, Dyck B, Chung F, Romanelli J, Chapman K R
Department of Anesthesia, University of Toronto, Toronto Hospital, Canada.
Anesthesiology. 1992 Nov;77(5):909-14. doi: 10.1097/00000542-199211000-00012.
The combined use of midazolam and spinal anesthesia is common in clinical practice. Despite the known potential for each to alter ventilation, the effect of their interaction has not been examined. Nineteen healthy volunteers were studied to assess the impact of intravenous midazolam (0.05 or 0.075 mg/kg), spinal anesthesia (T3-T8; mean level, T6), and their combination on resting ventilation and ventilatory responses to progressive hyperoxic hypercapnia. Resting ventilatory pattern was altered significantly by each condition. Midazolam caused a 29% decrease in resting tidal volume and a 24% decrease in mean inspiratory flow rate, while respiratory frequency increased by 14% and minute ventilation remained unchanged. By contrast, spinal anesthesia alone caused a 32% increase in tidal volume, a 24% increase in mean inspiratory flow rate, and a 13% increase in minute ventilation accompanied by a 14% decrease in respiratory frequency. The combination of midazolam and spinal anesthesia caused a significant decrease in minute ventilation (19%), tidal volume (28%), and mean inspiratory flow rate (27%), all of which were significantly more than the predicted sum of the individual interventions. Midazolam and spinal anesthesia each produced a significant decrease in hypercapnic ventilatory response slope, whereas their combination provoked no net change in hypercapnic ventilatory response slope. Interpretation of the hypercapnic ventilatory response data was complicated by shifts in the position of the ventilatory response curve, particularly under the spinal anesthesia condition. It is concluded that intravenous midazolam depresses resting ventilation, spinal anesthesia stimulates resting ventilation, and their combination has a modest synergistic effect of depressing resting ventilation.
咪达唑仑与脊髓麻醉联合使用在临床实践中很常见。尽管已知两者各自都有改变通气的潜在可能性，但它们相互作用的效果尚未得到研究。对19名健康志愿者进行了研究，以评估静脉注射咪达唑仑（0.05或0.075mg/kg）、脊髓麻醉（T3 - T8；平均平面，T6）及其联合使用对静息通气以及对渐进性高氧高碳酸血症的通气反应的影响。每种情况均显著改变了静息通气模式。咪达唑仑使静息潮气量降低29%，平均吸气流量降低24%，而呼吸频率增加14%，分钟通气量保持不变。相比之下，单独脊髓麻醉使潮气量增加32%，平均吸气流量增加24%，分钟通气量增加13%，同时呼吸频率降低14%。咪达唑仑与脊髓麻醉联合使用导致分钟通气量（19%）、潮气量（28%）和平均吸气流量（27%）显著降低，所有这些均显著大于各单独干预预期之和。咪达唑仑和脊髓麻醉各自均使高碳酸通气反应斜率显著降低，而它们联合使用时高碳酸通气反应斜率无净变化。通气反应曲线位置的改变使高碳酸通气反应数据的解读变得复杂，尤其是在脊髓麻醉情况下。结论是静脉注射咪达唑仑会抑制静息通气，脊髓麻醉会刺激静息通气，它们联合使用对抑制静息通气有适度的协同作用。
