The Use of C-reactive Protein as a Guide for Transitioning to Oral Antibiotics in Pediatric Osteoarticular Infections

Background: In the treatment of pediatric osteoarticular infections, early transition to oral antibiotics is desirable to shorten hospital stays and complications of prolonged intravenous therapy. C-reactive protein (CRP) is an acute phase reactant with a short half-life and is utilized at our institution to monitor progress and determine the transition to oral antibiotics. We hypothesized that patients can be safely transitioned from parenteral antibiotics to oral antibiotics when patients improve clinically and CRP halves over a period of 4 days. Materials and Methods: A retrospective review was conducted of all pediatric patients between the ages of 1 month and 18 years admitted and treated for acute bacterial osteomyelitis and/or septic arthritis at the authors' institution. We recorded all relevant data, inpatient progress, and outpatient follow-up. Results: Thirty-seven patients fulfilled the selection criteria and were reviewed for this study. Patients were an average of 8.37 +/- 4.91 years old. Surgery was performed in 33 patients (89.2%). The average duration of intravenous antibiotics was 11.00 +/- 5.61 days and the average duration of oral antibiotics was 28.76 +/- 8.69 days, with an average total duration of antibiotics of 39.16 +/- 9.08 days. The average peak CRP was 156.91 +/- 97.81 mg/L and the average CRP at discharge was 24.94 +/- 22.36 mg/L. Thirty-four patients (91.89%) experienced a 50% decline in CRP over 4 days. Of these patients, only 1 (2.94%) went on develop complications in the follow-up period. The average hospitalization period was 11.50 +/- 6.55 days. The average duration of follow-up was 7.83 +/- 6.56 months. Conclusions: We found that the combination of clinical improvement and a specific reduction of 50% in CRP levels over 4 days, or 5 CRP half lives, could be used to determine when to transition children with osteoarticular infections from parenteral to oral therapy. Complicated outcomes were associated with negative cultures, longer hospitalizations, and persistently elevated CRP levels. Level of Evidence: Level IV-Case Series