To the Editor:—
As stated by Marret et al. , 1posttonsillectomy hemorrhage (PTH) can be life-threatening, and an incidence of perhaps 4,500 per year in the United States with a reoperation rate of 1–5.5% is not insignificant, particularly when associated with concerns surrounding the administration of general anesthesia under such circumstances. Nonsteroidal antiinflammatory drugs (NSAIDs) are, however, now widely used not only in the operating room and ward but also at home, and they are widely believed to be safe and effective. Unfortunately, Marret et al. considered just seven investigations that satisfied their chosen criteria, none of which in fact reported a significant difference between the groups studied. Simply combining the results of these into a single analysis to create the reported result does not provide an adequate answer to the concerns expressed. In addition, anesthesiologists are aware that the chosen operative technique, together with the skill and experience of the operating surgeon, can be of significant importance. The total number of patients in the seven studies is small, with marked variability, including the NSAID chosen, the number of doses administered, the surgery undertaken, and whether a primary or secondary hemorrhage occurred. An additional qualifying study was not included. 2
In 1984, Carrick 3reported the potential adverse consequence of increased risk by salicylate administration on platelet function when PTH occurred in 14 of 359 patients versus just 1 of 353 patients receiving acetaminophen. NSAIDs, including aspirin (acetylsalicylic acid), inhibit platelet cyclooxygenase and prolong bleeding time by preventing the biosynthesis of thromboxane A2, leading to reduced platelet aggregation. NSAIDs are very widely used, and because they are available without prescription many patients take them perioperatively. To overcome this problem, the New York Eye and Ear Infirmary has instructed patients not to use aspirin or products containing aspirin, as well as other NSAIDs, for at least 7 to 10 days before and after surgery. 4This, as well the standard of specialist medical care, is reflected in their reported low incidence for PTH of 0.9% between 1992 and 1996.
Postoperative nausea and vomiting is also a relevant contributory factor. When compared with opioids, the value of NSAIDs in reducing this and avoiding the need for antiemetic administration is borne out by the only statistically significant difference reported in one of the seven included studies. 5
Since the late 1980s, the first author’s practice has been to administer diclofenac for pain control parenterally at the time of surgery, initially alone but subsequently together with morphine (after the now widely adopted combination had been shown to yield significant benefit). An initial audit for the years 1991 to 1994, when 2,136 tonsillectomies were performed in our hospital, revealed 10 cases requiring a return to the operating room for control of PTH (0.47%). Of the 378 patients who had received NSAIDs intraoperatively, only 1 was included in the 10 cases reported. These results suggested the practice to be safe but are in marked contrast to those subsequently published by Robinson and Ahmed 6describing a 5.5% incidence of PTH following the administration of diclofenac at induction versus 0.7% in controls. We have now retrospectively examined the relevant data contained in our operating room management system (ORSOS®; Per-Se Technologies, Atlanta, Georgia) for the years 1991 to 2002; these are presented in table 1.
The recorded incidence of PTH requiring reoperation is reassuringly low over the whole period except for the year 2001 (2.9%). Our figures do not suggest that the experience of either surgeon or anesthesiologist is a critical factor. We have no specific record of the frequency of use of NSAIDs in the postoperative period, but we know that they have been and continue to be widely prescribed. Our data could be interpreted as showing a weak relationship between the frequency of intraoperative use and PTH. The conclusion of Marret et al. 1that postoperative conventional NSAIDs increase the risk of reoperation for hemostasis and should not be used after tonsillectomy is too broad; it ignores the benefits provided by a reduction in both postoperative nausea and vomiting and postoperative pain, which themselves may contribute to an increased incidence of PTH. The effects on platelet function can be of long duration and would be expected to follow even a single dose given perioperatively. Administration at or before the time of surgery may beneficially allow hemostasis to be secured while the drug is active. This study has, however, usefully served to signal the urgent need for the performance of further randomized double-blind trials with both NSAID administration and surgical factors tightly controlled in an effort to bring clarity to this issue. NSAIDs were effective in these patients, and the cyclooxygenase-2 inhibitors are currently being promoted for perioperative use.