A comparison of early vs. late conversion from intravenous to oral therapy in the treatment of bacterial arthritis

PURPOSE: To determine whether early conversion to oral antibiotics made a significant difference in outcome of pediatric septic arthritis. METHODS: A 10 year, retrospective review of charts was made at two children's hospitals with differing philosphies regarding the routine length of intravenous (IV) antibiotics required to treat septic arthiritis. Inclusion criteria for the study were age ≤ 18 years, and septic arthritis diagnosed by one of the following: a positive joint culture or gram stain, a joint white blood cell count (WBC) > 20,000 cells/cc, or gross joint purulence. Patients with concurrent osteomyelitis were excluded. RESULTS:The patients from Hospital #1 (n=83) and Hospital #2 (n=117) were found to be clinically similar in their presentation, including age, temperature, delay of presentation, type and number of joints involved, and laboratory values (ESR, serum WBC, and joint WBC). Patients at Hospital #1 were converted to oral antibiotics sooner than at Hospital #2. (7.4±7.4 days vs.18.7±15.8 days). The total duration of antibiotic therapy was similar at both institutions, at 30.1±11.6 days vs. 30.8 ±13.8 days, respectively. On average, the patient's fever resolved after 2.4±3.2 days at Hospital #1 and 2.2±3.6 days at Hospital #2. Normalization of the sedimentation rate also occurred at a similar time for both groups, at 35.7±19.7 days (Hospital #1) and 30.8±41.3 days (Hospital #2). One patient at each hospital was readmitted for recurrent fever while on oral antibiotics. At the last follow-up visit, which occurred at 234±452 days for Hospital #1 and 198±638 days for Hospital #2, no patient was noted to have a lasting disability related to the joint infection and no cases of recurrent infection were noted. DISCUSSION: Despite similar patient pools, patients at Hospital #2 consistently received IV antibiotics longer than their counterparts at Hospital #1. The outcome of patients in both groups was excellent, and it is our conclusion that patients with isolated septic arthritis do not need long term IV antibiotics and can be safely converted to oral antibiotics after a brief course of IV antibiotics.