Dec. 15, 2000 -- Woody Allen defined major surgery as "anything being done to me," and like the filmmaker and comedian, many people prefer to be out cold when they're under the knife. But a new study suggests that people who receive regional anesthesia to block the pain to only part of the body during surgery may have a lower risk for complications or even death in the weeks and months immediately following the procedure than do people who receive general anesthesia.
Anesthesia can be delivered in one of three ways:
In general anesthesia, patients are given a combination of gases and/or drugs in the veins that suppress the pain-sensing central nervous system, essentially putting them into a form of sleep and forgetfulness. When delivered by a highly trained specialist, general anesthesia is a very safe and effective form of pain control.
Regional anesthesia, on the other hand, involves injecting drugs -- either into the spine or into nerves that supply a region of the body such as the chest, abdomen, or pelvis and legs -- that block pain signals from reaching the brain. An epidural, widely used in hospitals to dull labor pains while allowing women to stay awake and alert during childbirth, is one form of regional anesthesia.
The last form, local anesthesia, dulls sensation in a very small area -- for instance, a patch of skin -- and is used when performing relatively minor procedures.
To see whether the type of anesthesia used during surgery can make a difference in rates of serious complications or deaths following surgery, Anthony Rodgers, MD and colleagues from New Zealand, Denmark, the Netherlands, and the U.K. reviewed about 140 different studies comparing results of surgery performed with the patient under each type of anesthesia.
They found that the risk of death after surgery was about a third lower among patients who received regional anesthesia compared with those who were "put under" with general anesthesia. In addition, the risk of serious complications such as blood clots, pneumonia, infections, and breathing problems were all significantly lower among patients who received regional anesthesia, the researchers report in the Dec.16, 2000 issue of the British Medical Journal.
But a researcher who studies anesthesia tells WebMD that the type of review the researchers performed can be fraught with statistical problems that can make it difficult to accurately interpret results.
"[Death] from anesthesia is so low that it would need something like a million patients in total to see if there's any difference at all" between the two types of anesthesia, says Marsha M. Cohen, PhD, from the University of Toronto.
Rodgers and colleagues suggest that the differences in results could be attributable more to specific effects of regional anesthesia than to reduced use of general anesthesia. For example, regional anesthesia may be associated with better blood flow during surgery and fewer blood clots.
Regional anesthesia may also allow patients to breathe more freely without pain, and cause less strain on the body overall, the authors suggest, although they acknowledge that their study did not have the statistical power to provide a definitive answer.
"However, since serious complications associated with [regional anesthesia] ... are very rare, and more common side effects, such as headaches or urinary retention, are not life threatening, our data should result in more widespread use of spinal or epidural anesthesia," they conclude.