To the Editor:—
We read with great interest the report by Norris et al. 1“Double-masked randomized trial comparing alternative combinations of intraoperative anesthesia and postoperative analgesia in abdominal aortic surgery.” Since the landmark reports of Yeager et al. 2and Tuman et al. , 3it appeared that either intraoperative anesthesia or postoperative analgesia may indeed affect postoperative outcome in certain high-risk patients undergoing major operations. However, more recent studies have suffered methodologic deficiencies in trying to confirm or refute these findings. It is therefore quite gratifying to see a large, randomized, blinded clinical trial to determine what effect, if any, intraoperative anesthesia and postoperative analgesia has on outcome and length of stay in these high-risk patients.
However, we do not believe the findings of Norris et al. support the conclusion that intraoperative anesthesia or postoperative analgesia “offers no major advantage or disadvantage.”1Multiple studies consistently demonstrate that postoperative epidural analgesia provides superior pain relief compared with systemic opioids. 4–10However, Norris et al. states “there were no differences in VAS pain scores over time among the four treatment groups for VAS-least pain, VAS-now pain, or VAS-cough pain.”1The mechanism by which previous papers demonstrated improved outcome is unclear. 2,3The working hypothesis is that epidural analgesia blunts the stress response either through improved analgesia or sympatholysis. This stress reduction then attenuates the postoperative hypercoagulable state, thereby improving outcome. If, as in Norris et al. , postoperative pain scores are the same in all groups, how would one ever expect to see a difference in outcome? If the patients had received more aggressive dosing regimens and thus produced the expected better pain control in the epidural groups, one might then expect an outcome difference.