Sandler A N, Chovaz P, Whiting W
Can Anaesth Soc J. 1986 Sep;33(5):542-9. doi: 10.1007/BF03014258.
Thirteen post-thoracotomy patients were entered into a double-blind, randomized clinical trial comparing the effects of epidural morphine (Group E) and intravenous morphine (Group I) on postoperative respiratory depression. Postoperative respiratory depression was assessed for 24 hours by (a) PaCO2 at 2, 6, 12 and 24 hours (b) hourly assessment of respiratory rate (RR) (c) presence of respiratory rate of less than ten breaths per min for greater than 5 min (SRR) (d) hypopnoea/apnoea (H/A). RR, SRR, and H/A were measured using respiratory inductive plethysmography. PaCO2 was significantly elevated at 2, 6 and 12 hours in Group E and only at two hours in Group I. One of five patients in Group I had a single episode of SRR whereas five of eight patients in Group E had multiple episodes of SRR. None of the patients in Group I had H/A episodes, in contrast to six of eight in Group E who had numerous H/A episodes post-operatively. This difference was statistically significant. Multiple doses of epidural morphine produce an insidious and unpredictable change in respiratory pattern. Electronic monitoring is useful to assess those at risk of overdose and possible respiratory arrest.
13例开胸术后患者进入一项双盲随机临床试验，比较硬膜外注射吗啡（E组）和静脉注射吗啡（I组）对术后呼吸抑制的影响。术后24小时通过以下指标评估呼吸抑制情况：(a) 术后2、6、12和24小时的动脉血二氧化碳分压（PaCO2）；(b) 每小时评估呼吸频率（RR）；(c) 呼吸频率低于10次/分钟持续超过5分钟（SRR）；(d) 呼吸浅慢/呼吸暂停（H/A）。RR、SRR和H/A采用呼吸感应体积描记法测量。E组术后2、6和12小时PaCO2显著升高，而I组仅在术后2小时PaCO2显著升高。I组5例患者中有1例出现单次SRR，而E组8例患者中有5例出现多次SRR。I组患者均未出现H/A发作，相比之下，E组8例患者中有6例术后出现多次H/A发作。这种差异具有统计学意义。多次剂量的硬膜外吗啡会导致呼吸模式发生隐匿且不可预测的变化。电子监测有助于评估有用药过量和可能呼吸骤停风险的患者。
