Perforated and Gangrenous Appendicitis: An Analysis of Antibiotic Failures

Abstract

The relationships between resistant pathogens, serum levels of gentamicin, and the outcomes of gangrenous or perforated appendicitis were analyzed in 147 patients. Failure to cure the infection occurred significantly more frequently among patients treated with cefoperazone or cefamandole than among those treated with clindamycin and gentamicin in combination. The failures were associated with recovery of resistant Bacteroides fragilis from intraoperative cultures. Pseudomonas species were also associated with failures, their in vitro susceptibility not correlating with clinical cure. Patients with gentamicin peak serum levels of less than 6 micrograms/ml in the first three days were not more likely to be associated with failure than were patients with higher levels. These clinical observations indicate that antibiotic therapy of intra-abdominal sepsis should include antibiotics with in vitro activity against B fragilis and that precise adjustments of gentamicin levels may not improve outcome. In addition, Pseudomonas species may play a significant role in some of these infections.

Role of aminoglycoside antibiotics in the treatment of intra-abdominal infection

“…might have had a particular benefit from the aminoglycosidecontaining regimen. Such a benefit was suggested by one study (18).…”

“…Lau et al (22) also showed a failure rate with cefoperazone (20%) significantly higher than that with moxalactam (8%) in patients with perforated or gangrenous appendicitis. In a further analysis of data from the first study, the likelihood of failure was found to be greatest in patients from whom B. fragilis isolated from the abdominal cavity at surgery was resistant to the antibiotics used (18). A previous report likewise suggested that failures of treatment of intra-abdominal infection with moxalactam were predicted by the finding of moxalactam-resistant anaerobic bacteria in the initial cultures (30).…”

“…was isolated from the initial culture. In a study of patients with a perforated or gangrenous appendix, Heseltine et al (18) examined the correlation between the susceptibility or resistance of P. aeruginosa strains isolated from the initial culture and the outcome of treatment with various regimens ( Table 6). In that study, 30% of patients had peritoneal cultures which were positive for P. aeruginosa.…”

Correlation of various in vitro testing methods with clinical outcomes in patients with Bacteroides fragilis group infections treated with cefoxitin: a retrospective analysis

“…There are a number of factors which are thought to be predictive of the clinical outcome of intraabdominal sepsis, including the site and extent of infection, the severity of the underlying illness, the nutritional status of the patient, the operative procedure, and the antimicrobial therapy used (1,6,9,12).…”

“…The issue of clinical correlation with anaerobic susceptibility testing has been raised recently (8) (9). However, the question of "relative" susceptibility with an "active" agent like cefoxitin and the role of susceptibility to outcome has never been addressed.…”