Mortality from appendicitis rarely occurs, and morbidity has been decreasing with the development of new therapies. The use of perioperative antibiotics has reduced the incidence of the most serious infectious complication, postsurgical intra-abdominal abscess formation. Three to 14 days of antibiotic therapy generally are recommended for patients with gangrenous or perforated appendicitis, although the ultimate decision about the duration of treatment remains with the treating physician. Hoelzer and associates identified criteria to determine when adequate antibiotic therapy has been administered and when it may be discontinued safely. Decreasing the duration of treatment would shorten the length of hospital stays and lower the cost of treatment while reducing the risk of drug-related toxicities.

Thirty-three consecutive children who underwent surgery for grossly apparent perforation or gangrenous appendicitis received preoperative or perioperative antibiotics. Antibiotic therapy was continued postoperatively until patients were able to eat, were afebrile (temperature less than 38°C [100.4°F] for 24 hours) and had a normal white blood cell count with immature neutrophil counts (bands) of less than 3 percent. At this point, patients were considered to have met the criteria to stop antibiotic therapy and were discharged. Patients were monitored for at least two months after discharge.

Of the 32 children who met the criteria, all but one recovered without recurrent intra-abdominal abscess or wound infection. Thus, the predictive value for the criteria was 97 percent (31 of 32 children). One child did not meet the criteria before antibiotics were discontinued. He was able to eat and had a normal white blood cell count, so he was discharged despite a temperature of 38.5°C (101.3°F). He was readmitted seven days later with an intra-abdominal abscess below the appendectomy incision. Therefore, the predictive value of failure to meet the criteria was 100 percent (one of one child).

The authors conclude that combining physical examination with laboratory evaluation accurately determines when antibiotic treatment can be discontinued safely. They recommend, however, that because of their small sample size, evaluation of the criteria in a larger clinical study is necessary.