Study Shows Epidural Anaesthesia Is Safe But Only Slightly Improves Survival

Main Category: Pain / Anesthetics
Also Included In: Clinical Trials / Drug Trials
Article Date: 11 Aug 2008 - 0:00 PDT

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A study of quarter of a million patients has shows that epidural anaesthesia / analgesia* (EA) is safe for patients undergoing intermediate to high-risk surgery other than cardiac surgery. However people given EA have only a very slightly increased survival compared with those who do not. These are the conclusions of authors of an Article published early Online and in an upcoming edition of The Lancet.

EA offers better postoperative pain relief than intravenous opioid drugs, and also reduces the surgical stress response, which has theoretical benefits for cardiovascular, respiratory, gastrointestinal, and metabolic function. But until now one important question has remained unanswered: do these benefits of EA translate into improved survival for the patients who receive it? Dr Duminda Wijeysundera, from Ontario's Institute for Clinical Evaluative Sciences, and Department of Anaesthesia, Toronto General Hospital and University of Toronto, Canada, and colleagues did a retrospective study of 259 037 Ontario patients to investigate.

The patients in the study were all aged 40 years or over, and had had selected elective intermediate to high-risk non-cardiac surgery between 1994 and 2004. A total of 56 556 (22%) of these patients received EA, and the procedure was associated with a small reduction in 30-day mortality (1•7%) compared with patients who had not had EA (2•0%). Put another way, 477 patients had to have had EA to avert one death.

The authors conclude: "Epidural anaesthesia was 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 - for example, improving postoperative pain relief or preventing postoperative lung complications."

In an accompanying Comment, Dr Michael Barrington and Dr David Scott, Department of Anaesthesia, St Vincent's Hospital, Melbourne, VIC, Australia, say: "Wijeysundera and colleagues point out that our focus should be on the proven benefits of epidural analgesia. The most durable and clearly defined benefit of epidural analgesia is improved analgesia. Provision of effective analgesia is our core business: it has substantial physiological and psychological benefits, and is regarded as a fundamental human right. Pain after major surgery can be severe, and we think that in many cases pain relief alone is an unambiguous clinical indication for postoperative epidural analgesia."

"Epidural anaesthesia and survival after intermediate-to-high risk non-cardiac surgery: a population-based cohort study"
Duminda N Wijeysundera, W Scott Beattie, Peter C Austin, Janet E Hux, Andreas Laupacis
The Lancet - Published OnlineAugust 11, 2008DOI:10.1016/S0140-6736(08)61121-6

COMMENT
"Do we need to justify epidural analgesia beyond pain relief?"
The Lancet - Published OnlineAugust 11, 2008DOI:10.1016/S0140-6736(08)61122-8

http://www.thelancet.com

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