Single dose of antibiotics may be just as effective as multiple doses in preventing infections after an appendectomy

Jul 20 2005

A single dose of antibiotics may be just as effective as multiple doses in preventing infections after an appendectomy, a new research review confirms.

Researchers at Bispebjerg Hospital in Copenhagen analyzed 45 controlled clinical trials in which antibiotics to fight wound infections following appendectomies were compared with placebo. Sixteen of the trials also included data on the development of an intra-abdominal abscess, or an infected pocket of pus formed by a ruptured appendix. In all, 9,576 patients were included in the analyses.

The review found that antibiotic injections do work no matter how diseased the appendix was or whether it was diseased at all. This is significant, because some surgeons contend that antibiotics should be used only when the appendix is at a more advanced stage of disease.

The study also indicates that a single antibiotic dose has the same impact as multiple doses, and that if multiple doses are used, it does not matter whether they are given before, during or after the operation.

The study appears in the July issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that produces systematic reviews of healthcare interventions, based on the content and quality of existing clinical trials on the topic.

"I don't think that there is any controversy any longer about whether antibiotics work," says co-author Henning Andersen, Ph.D. "What we need to focus on now are factors such as dosage, administration time and length of administration. Why give patients a lot of antibiotics if just one shot could help prevent wound infection or abscess?"

Andersen says that the most important reason for giving a single dose rather than multiple doses is to prevent the development of antibiotic resistance. "Cost is not really a factor," says Andersen. "Antibiotics are fairly inexpensive drugs, so it's not from an economic point of view that you should reduce their use. You should reduce their use so that you won't develop resistance."

Timothy Babineau, M.D., associate professor of surgery at the Boston University School of Medicine, says that all surgeons now use antibiotics for appendectomies but how they use them varies enormously. "Practitioners are all over the map on this," he says. "They tend to practice the way they were taught."

Babineau is skeptical about whether a single antibiotic dose would be sufficient in all cases. "The problem now is that we're under so much pressure to limit our antibiotic usage in all diseases because of the problems with resistant strains of organisms," he says. "I think perhaps we may be seeing the pendulum swing too far in the wrong direction, where patients are not receiving adequate antibiotic coverage. A decade or even five years ago, the opposite was true."

The authors first published a review of antibiotic use during appendectomies in 2001 and then updated it in 2003. This 2005 paper is the second time that the review has been updated.

Appendicitis is the most common cause of acute abdominal pain requiring surgery. The overall lifetime risk for acute appendicitis is between 6 percent and 20 percent but occurs most frequently in adolescents. The incidence of appendicitis in children and in adults past the age of 70 years is small.

The review was funded by the Danish Pharmacy Foundation of 1991, the Danish Institute for Health Technology Assessment, and the Copenhagen Hospital Corporation.