To the Editor:—

The role of epidural analgesic techniques to improve postoperative outcome has not been defined and remains to be debated 1. Norris et al . 2published a very ambitious double-masked randomized trial to define the role of epidural analgesia to improve outcome in abdominal aortic surgery. In the same issue an editorial 2praised the high quality of design in the Norris study.

We agree that the Norris study is a well-designed study, and it may be a little unfair to criticize it, also because it was performed between 1993 and 1997, at a time when most researchers of pain relief and surgical outcome had not realized that many of the outcome parameters studied may be determined by factors other than pain relief and its physiologic effects 3. However, it may not, in 2001, be appropriate to conclude that “thoracic epidural analgesia followed by epidural patient controlled analgesia offers no major advantage or disadvantage on outcome after abdominal aortic surgery.”2First, there is no exact information on the dose per hour of local anesthetic used in the epidural regimen, although it appears that it was a very weak local anesthetic regimen, thereby merely reflecting an epidural opioid regimen. This may be important when outcome parameters such as pain and paralytic ileus are considered, since they are dependent on the amount of local anesthetic included in the epidural regimen. 4,5Thus, paralytic ileus (which may be a very important factor in determining length of stay after aortic surgery) has uniformly been effective to reduce ileus with a dose of about 10 mg bupivacaine per hour, 5while epidural opioids have not been demonstrated to reduce ileus. Finally, although the outcome assessments were clearly described, they may not be valid to support the conclusions, because a rather restrictive rehabilitation regimen was used with 24-h nasogastric intubation, and slowly progressed toward normal oral intake, a regimen not supported from scientific documentation. 3 

Thus, the jury is still out when debating the effect of postoperative epidural analgesia on surgical outcome, and it should be kept in mind that “epidural analgesia” is not always “epidural analgesia” but depends on the composition and infusion rate of the treatment. Most importantly, the advantageous physiologic effects of thoracic epidural local anesthetics 3have to be integrated into an accelerated rehabilitation program to improve postlaparotomy outcome. 1,3 

Kehlet H, Holte K: Effects of postoperative analgesia on surgical outcome. Br J Anaesth 2001; 87: 62–72
1. Norris EJ, Beattie C, Perler BA, Martinez EA, Meinert CL, Anderson GF: Double-masked randomized trial comparing alternate combinations of intraoperative anesthesia and postoperative analgesia in abdominal aortic surgery. A nesthesiology 2001; 95: 1054–67
Kehlet H: Multimodal approach to control postoperative pathophysiology and rehabilitation. Br J Anaesth 1997; 78: 606–17
Jørgensen H, Wetterslev J, Möiniche S, Dahl JB: Epidural local anaesthetics vs. opioid-based analgesic regimens on postoperative gastrointestinal paralysis, PONV and pain after abdominal surgery (Cochrane Review), Cochrane Database Syst Rev 2000; 4:CD001893
Holte K, Kehlet H: Postoperative ileus: a preventable event ? Br J Surg 2000; 87: 1480–93.