Abstract
C-reactive protein (CRP) level is used at our tertiary paediatric hospital in the diagnosis, management, and discharge evaluation of paediatric septic arthritis patients. The purpose of this study was to evaluate the efficacy of a discharge criterion of CRP less than 2 mg/dL for patients with septic arthritis in preventing reoperation and readmission. We also aimed to identify other risk factors of treatment failure.
Patients diagnosed with septic arthritis between January 1, 2007 and December 31, 2017 were reviewed retrospectively. The diagnosis of septic arthritis was made based on clinical presentation, laboratory results and the finding of purulent material on joint aspiration or the isolation of a bacterial pathogen from joint fluid or tissue. Bivariate tests of associations between patient or infection factors and readmission and reoperation were performed. Quantitative variables were analyzed using Mann-Whitney tests and categorical variables were analyzed using Chi-square tests.
One hundred eighty-three children were included in the study. Seven (3.8%) were readmitted after hospital discharge for further management, including additional advanced imaging, and IV antibiotics. Six (85.7%) of the readmitted patients underwent reoperation. Mean CRP values on presentation were similar between the two groups: 8.26 mg/dL (± 7.87) in the single-admission group and 7.94 mg/dL (± 11.26) in the readmission group (p = 0.430). Mean CRP on discharge for single-admission patients was 1.71 mg/dL (± 1.07), while it was 1.96 mg/dL (± 1.19) for the readmission group (p = 0.664), with a range of < 0 .8 to 6.5 mg/dL and a median of 1.5 mg/dL for the two groups combined. A total of 48 children (25.9%) had CRP values greater than the recommended 2 mg/dL at discharge, though only three of these patients (6.2%) were later readmitted. The only common variable in the readmitted children was either a negative culture result at time of discharge or atypical causative bacteria.
CRP values are useful in monitoring treatment efficacy but not as reliable as a discharge criterion to prevent readmission or reoperation in children with septic arthritis. We recommend determining discharge readiness on the basis of clinical improvement and downtrending CRP values. There was a higher risk of readmission in children with an atypical causative bacteria and when culture results were negative at discharge. Close monitoring of these patients after discharge is suggested to identify signs of persistent infection.
