Appendectomy is the fourth most common abdominal surgery performed in the United States. Up to 18 percent of patients have postoperative infectious complications ranging in significance from wound infection to intra-abdominal abscess. The rate of infections depends on the degree of contamination during surgery and reaches nearly one third of cases when the appendix is perforated or gangrenous. Helmer and colleagues studied the effect of an evidence-based clinical practice guideline in reducing infectious complications of appendectomy.
The clinical practice protocol that was developed from a critical review of the literature (see accompanying figure) was applied to 206 patients with a presumptive diagnosis of appendicitis who presented to a Texas county hospital during 1999. Outcomes in this cohort of patients were compared with those in 232 patients treated for the same condition at the hospital during the previous year. No patients were excluded from the study. Data were gathered on demographic and surgical features, comorbidities, use of antibiotics, evidence of infection, and other complications during the hospital stay.
Eight patients (4 percent) who were treated according to the protocol had postoperative surgical infections, compared with 20 patients (9 percent) in the comparison group. The number of patients with intra-abdominal abscesses dropped from 12 to five after introduction of the protocol, and the number of wound infections dropped from 14 to four. The improvement was particularly significant in patients presenting with a perforated or gangrenous appendix. In these patients, the total number of infections dropped from 16 (33 percent) to five (13 percent).
The authors conclude that use of an evidence-based clinical practice guideline can significantly reduce surgically related infections following appendectomy and is particularly effective in patients with perforation or gangrene of the appendix.
editor's note: It is good to see the application of evidence-based practice result in positive outcomes for a common condition. This study should be directly applicable to practice in many locations, although the antibiotics selected for this study (gentamicin, levofloxacin, metronidazole, cefotetan, and imipenem) probably are not those of first choice in most institutions. The authors do not tell us how they persuaded all surgeons to adhere to the protocol (if they did). Getting consensus to consistently implement a clinical guideline is the most difficult part of the entire process. One wishes that they had measured additional outcomes, such as length of stay or reduction in other infections, especially of the respiratory and urinary tracts. Those of us who might be tempted to introduce the protocol into our own hospitals need all the available information to persuade our colleagues to abdicate personal practice preferences in favor of evidence-based protocols.—a.d.w.