Factors affecting the successful management of intra-abdominal abscesses with antibiotics and the need for percutaneous drainage.

Purpose: There is no definite consensus on the management of intra-abdominal abscesses in adults. This retrospective study evaluated the use of antibiotic therapy and percutaneous image-guided drainage in adult patients with intra-abdominal abscesses.
Methods: A retrospective chart review of 114 patients with intra-abdominal abscesses was conducted. Data collected included patient demographics, presenting symptoms, radiographic interpretation, vital signs, antibiotic coverage, laboratory values, and details of the hospital course. Bivariate statistical tests were performed using the Wilcoxon rank-sum test, chi-squared test, or Fisher's exact test, where appropriate.
Results: Sixty-seven of 114 patients (59 percent) had intra-abdominal abscesses resulting from appendicitis, diverticulitis in 30 patients (26 percent), postoperative in 13 patients (11 percent), and undetermined in 4 patients (4 percent). Three patients (3 percent; 95 percent confidence interval, 1-8 percent) failed conservative management and underwent urgent operation. Sixty-one (54 percent; 95 percent confidence interval, 44-63 percent) patients improved with intravenous antibiotic therapy alone. Fifty patients (44 percent; 95 percent confidence interval, 35-54 percent) underwent image-guided percutaneous drainage after 48 to 72 hours of antibiotic therapy. Patients who improved on antibiotics alone had average abscess diameter of 4 cm, whereas patients who underwent percutaneous drainage had average diameter of 6.5 cm (P<0.0001). Maximal temperature at time of admission was 100.8 degrees F for antibiotic group and 101.2 degrees F for percutaneous drainage group (P=0.0067).
Conclusions: The majority of the patients with intra-abdominal abscesses improved with antibiotic therapy alone. Those patients with an abscess diameter>6.5 cm and temperature at admission>101.2 degrees F have higher likelihood of failing conservative therapy with antibiotics alone and requiring percutaneous drainage.