The diagnostic value of repetitive preoperative analyses of C-reactive protein and total leucocyte count in patients with suspected acute appendicitis.

BACKGROUND

Studies have shown that C-reactive protein (CRP) and total leucocyte count (WBC) in suspected acute appendicitis analysed only on admission gave valuable information to guide the surgeon. The aim of this study was to investigate the usefulness of CRP and WBC measured repetitively before operation.

METHODS

During a 1-year period 227 patients were studied before emergency appendicectomy. CRP and WBC were analysed every 4th h. The upper limits of the reference intervals used were 9.0 x 10(9)/l for WBC and 10 mg/l for CRP.

RESULTS

Of the 227 appendicectomized patients, 170 (75%) had acute appendicitis. Sixty-six of the patients were tested on two or more occasions every 4th h. Forty-six of these patients had appendicitis; repetitive tests showed a continuing rise in CRP values but a continuing decrease in WBC. The negative appendicectomy rate among these 66 patients was 30%, which theoretically would have fallen to 19% if patients with normal results had not been subjected to surgery.

CONCLUSIONS

Repeated laboratory tests for CRP and WBC should be performed in patients with suspected acute appendicitis requested to stay for further observation. If these test results are normal, the surgeon should preferably refrain from operating but consider other differential diagnoses.