Recognition of tubo-ovarian abscess in adolescents with pelvic inflammatory disease

Abstract

Ultrasonography of the pelvis is commonly used to diagnose tubo-ovarian abscess (TOA) in patients with pelvic inflammatory disease (PID). Our objective was to determine whether the clinical features of PID differ in adolescents with and without TOA. A retrospective design was used to derive and validate a clinical model differentiating adolescents with PID who did and did not have TOA. The study population consisted of hospitalized adolescents with a discharge diagnosis of PID. Of the 208 patients discharged from January 1, 1990, to July 31, 1993, 87 (42%) met published criteria for PID and comprised the derivation set. Of the 63 patients from August 1, 1993, to June 24, 1994, 30 (48%) met criteria and comprised the validation set. All patients had pelvic ultrasonography performed during hospitalization. The ultrasonography records were reviewed retrospectively for TOA, ovarian and uterine size, clarity of tissue planes, and endometrial or cul-de-sac fluid. Medical records were reviewed for sociodemographic characteristics, medical and sexual history, physical examination, laboratory results, and hospital course. TOA was present in 17% of the derivation set and 20% of the validation set. A six-variable model developed on the derivation set performed best in differentiating the TOA and non-TOA groups: last menstrual period > 18 days prior to admission (60% and 17%), previous PID (53% and 22%), palpable adnexal mass (13% and 3%), white blood cell count > or = 10,500/microliters (33% and 64%), erythrocyte sedimentation rate > 15 mm/h (33% and 64%), and heart rate > 90/min (40% and 78%). In the derivation and validation sets, the model correctly identified 78 and 83% of the TOA groups and 88 and 77% of the non-TOA groups. The area under the receiver operating characteristic curve of the model was 0.92 in the derivation set and 0.87 in the validation set. We conclude that clinical characteristics help identify adolescents with acute PID who have TOA. These patients may have fewer signs of acute illness than those without TOA and may develop symptoms later in the menstrual cycle.