Evaluation of procalcitonin as a marker to predict antibiotic response in adult patients with acute appendicitis: a prospective observational study.

BACKGROUND: The aim of the study was to investigate the value of serum procalcitonin (PCT) as a predictor of early antibiotic treatment response in patients with acute appendicitis. Procalcitonin is a biochemical marker that increases rapidly in cases of bacterial infection and sepsis; however, the benefit of PCT as a diagnostic tool in acute appendicitis has not been confirmed.

METHODS: Observations of PCT dynamics were conducted as part of a prospective clinical trial at Sahlgrenska University Hospital between May 2009 and February 2010 on adult patients with acute appendicitis treated with antibiotics as first-line therapy. Procalcitonin, C-reactive protein (CRP), and white blood cell count (WBC) were measured before administration of antibiotics and subsequently between 4-24 h following treatment.

RESULTS: Three hundred sixteen patients were included in the study. Almost 80% recovered on antibiotics without the need of surgery. Serum PCT concentrations before initiation of antibiotic therapy and during treatment did not differ significantly between antibiotic responders and non-responders (p<0.94). However, differences were observed for CRP (p<0.04) and WBC (p<0.001), with a trend for body temperature (p<0.06).

CONCLUSION: Procalcitonin has limited additional value, compared with standard laboratory tests as CRP, WBC, and body temperature to predict antibiotic treatment response in adult patients with acute appendicitis.