The role of low CRP values in the prediction of the development of acute diverticulitis

Computed tomography (CT) is the most appropriate imaging modality for the assessment of acute diverticulitis at the emergency unit. The aim of this study was to determine the clinical outcome of the patients presented first time with symptoms of acute diverticulitis and low CRP values. Two-hundred patients, who presented with the symptoms of acute diverticulitis and had CRP values under 150 mg/L, underwent abdominal CT examination on admission to Oulu University Hospital. The clinical parameters and radiological findings were compared in relation to clinical outcome both by means of univariate and multivariate analyses. Seventy-one (35.5 %) of the 200 patients presented on admission with complicated diverticulitis. CRP values between 100 and 150 mg/L predicted complicated disease, but the mean values of CRP between uncomplicated disease, 89 mg/L +/- 39, and complicated disease, 101 mg/L +/- 39, did not differ significantly. Free intra-abdominal fluid in CT was the only independent risk factor of the need for interventional therapy and treatment in the intensive care unit. Longevity of the patients and free fluid in CT predicted significantly prolonged hospitalization. Mortality was 1 % and older patients were significantly affected. The recurrence rate of acute diverticulitis was 24 % (43/177) in the whole group and 18 % (23/129) after uncomplicated diverticulitis. Low CRP values do not reliably predict uncomplicated disease in patients presented first time at the emergency unit with acute diverticulitis. We recommend that the need for abdominal CT is carefully evaluated according to the patient's clinical status, always even when the CRP value is under 150 mg/L.