Blood culture results do not affect treatment in complicated cellulitis

Cellulitis, a frequently encountered complaint in the Emergency Department, is typically managed with antibiotics. There is some debate as to whether obtaining blood cultures and knowing their results would change the management of cellulitis, although most authors argue that information from blood cultures does not change the empirical management of uncomplicated cellulitis. However, for complicated cellulitis (as defined by the presence of significant comorbidity), there is considerable disagreement and lack of evidence as to the utility of blood cultures.

Our aim was to determine the role of blood cultures in the management of complicated cellulitis.

This retrospective chart review assessed the utility of obtaining blood cultures in complicated cellulitis (as defined by active chemotherapy, dialysis, human immunodeficiency virus/acquired immune deficiency syndrome, diabetes, or organ transplantation) vs. a cohort of individuals without medical comorbidity.

Six hundred and thirty-nine patients were identified, 314 of which were deemed cases and 325 controls. Within the cases, 29 of 314 returned as positive blood cultures vs. 17 of 325 positive blood culture controls within the cases (p = 0.05; odds ratio = 1.84; 95% confidence interval 0.99-3.43). A clinically significant change in management (a change in the class of antibiotic) was found in 6 of 314 cases vs. 4 of 325 controls (p = 0.578; odds ratio = 1.5525; 95% confidence interval 0.434-5.5541).

Within this cohort of patients with complicated cellulitis, blood cultures rarely changed management from empirical coverage.