Plasma D-lactic acid level: a useful marker to distinguish perforated from acute simple appendicitis

Early diagnosis of perforated appendicitis is important for reducing morbidity rates. The aim of this study was to determine the value and utility of plasma D-lactic acid levels in identifying the type of appendicitis. In this clinical study, plasma D-lactic acid levels were assessed in 44 consecutive paediatric patients (23 with acute appendicitis, 21 with perforated appendicitis) before laparotomy. D-lactic acid levels were determined by an enzymatic spectrophotometric technique using a D-lactic acid dehydrogenase kit. Patients with perforated appendicitis had higher D-lactic acid levels (3.970 +/- 0.687 mg/dL) than patients in the control group (0.478 +/- 0.149 mg/dL) and patients with acute appendicitis (1.409 +/- 0.324 mg/dL; p < 0.05). For a plasma D-lactic acid level greater than 2.5 mg/dL, the sensitivity and specificity of the D-lactic acid assay were 96% and 87%, respectively. The positive predictive value was 87%, the negative predictive value was 96%, and the diagnostic value was 91%. These results suggest that the measurement of plasma D-lactic acid levels may be a useful adjunct to clinical and radiological findings in distinguishing perforated from acute non-perforated appendicitis in children.