In a report published in the British Medical Journal issue from March 24, 2001, researchers report that women apparently awaken from general anesthesia faster than men do. However, at the same time, they are slower to return to their before surgery health status after surgery and anesthesia. The report, from Dr. Paul Myles and others at the Alfred Hospital of Victoria, Australia involved four hundred and sicty three patients (241 men and 222 women).

Overall, women wake-up or "emerge" from anesthesia at a quicker rate than men - a difference that could be explained by differences in physiology, enzyme activity, etc. The investigators noted that hormonal differences account for changes in the function of the GABA receptor - a receptor known to be important in the action of many anesthetics.

Despite this faster wake-up, however, the quality of their recovery as judged by the reporting of complications was significantly worse. As a result, it did not appear that women were able to be discharged from the post-operative recovery room any faster. The authors observed that additional time taken to treat even minor complications can lengthen time spent in the recovery room.

In addition to the above findings, the women took longer to return to their pre-surgery baseline health status (reported 25% longer) and experienced a higher absolute number of complications than men did. The authors speculate about some of the reasons for this in their comments. For example, differences in the incidence of back pain may be related to anatomical differences affecting the lower spine. In addition, postoperative nausea and vomiting has some relationship in women to the phase of the menstrual cycle. Also, women have a higher incidence of migraines and tension headaches - both risk factors for headaches after anesthesia and surgery.

The investigators admit that one explanation for the differences in complication rate would be that women may be more willing to report problems and complications. However, since all participants were questioned directly and specifically about complications, this effect is likely to be minimized, if present at all. The authors do not believe this to be a true explanation and state that the differences found are likely to be "genuine and important."

The authors are examining similar issues with other types of anesthesia as well. If you are interested in more details, the full-text of this report is available from the website of the British Medical Journal.