Wijeysundera Duminda N, Beattie W Scott, Austin Peter C, Hux Janet E, Laupacis Andreas
Department of Health Policy Management and Evaluation, University of Toronto, Toronto, ON, Canada.
Lancet. 2008 Aug 16;372(9638):562-9. doi: 10.1016/S0140-6736(08)61121-6. Epub 2008 Aug 8.
Although epidural anaesthesia and analgesia have numerous benefits, their effects on postoperative survival are unclear. We therefore undertook a population-based cohort study to determine whether perioperative epidural anaesthesia or analgesia is associated with improved 30-day survival.
We used population-based linked administrative databases to do a retrospective cohort study of 259 037 patients, aged 40 years or older, who underwent selected elective intermediate-to-high risk non-cardiac surgical procedures between April 1, 1994, and March 31, 2004, in Ontario, Canada. Propensity-score methods were used to construct a matched-pairs cohort that reduced important baseline differences between patients who received epidural anaesthesia or analgesia as opposed to those that did not. We then determined the association of epidural anaesthesia with 30-day mortality within these matched-pairs.
Of the 259 037 patients, 56 556 (22%) received epidural anaesthesia. Within the matched-pairs cohort (n=88 188), epidural anaesthesia was associated with a small reduction in 30-day mortality (1.7%vs 2.0%; relative risk 0.89, 95% CI 0.81-0.98, p=0.02).
Epidural anaesthesia and analgesia were associated with a small improvement in 30-day survival, but this effect should be interpreted cautiously. The estimate had borderline significance, despite a large sample size. Its absolute magnitude was also small, corresponding to a number needed to treat of 477. Our study, therefore, does not provide compelling evidence that epidural anaesthesia improves postoperative survival. Nonetheless, our results support the safety of perioperative epidural anaesthesia when used for indications other than improving survival (eg, improving postoperative pain relief, preventing postoperative pulmonary complications).
尽管硬膜外麻醉和镇痛有诸多益处，但其对术后生存率的影响尚不清楚。因此，我们开展了一项基于人群的队列研究，以确定围手术期硬膜外麻醉或镇痛是否与30天生存率的提高相关。
我们使用基于人群的关联行政数据库，对1994年4月1日至2004年3月31日在加拿大安大略省接受选定的择期中高风险非心脏外科手术的259037名40岁及以上患者进行了一项回顾性队列研究。倾向评分方法用于构建一个配对队列，以减少接受硬膜外麻醉或镇痛的患者与未接受者之间重要的基线差异。然后，我们在这些配对中确定硬膜外麻醉与30天死亡率之间的关联。
在259037名患者中，56556名（22%）接受了硬膜外麻醉。在配对队列（n=88188）中，硬膜外麻醉与30天死亡率的小幅降低相关（1.7%对2.0%；相对风险0.89，95%CI 0.81-0.98，p=0.02）。
硬膜外麻醉和镇痛与30天生存率的小幅提高相关，但对此效应应谨慎解读。尽管样本量很大，但该估计值具有临界显著性。其绝对幅度也很小，对应于477的需治疗人数。因此，我们的研究并未提供令人信服的证据表明硬膜外麻醉可提高术后生存率。尽管如此，我们的结果支持围手术期硬膜外麻醉用于提高生存率以外的其他适应证（如改善术后疼痛缓解、预防术后肺部并发症）时的安全性。
