Background: The aim was to measure the accuracy of pleural fluid lactate concentration for diagnosis of parapneumonic pleural effusion (PPE) and to discriminate between uncomplicated (UPPE) and complicated PPE (CPPE).
Methods: Pleural fluid lactate was measured in patients with pleural effusion. Patients were classified into two groups according to the etiology of pleural effusion: PPE and NOT PPE.
Results: We studied 173 patients. Thirty patients were PPE (10 UPPE and 20 CPPE) and 143 were NOT PPE. The AUC value was 0.831 (p < 0.0001) and the optimal cutoff value was 5.6 mmol/L exhibiting 70% sensitivity and 90.9% specificity for diagnosis of PPE. Also, pleural fluid lactate could be used to discriminate between UPPE and CPPE, the AUC value was 0.740 (p = 0.0089) and the optimal cutoff value was 10.2 mmol/L, exhibiting 45% sensitivity and 90% specificity.
Conclusions: Pleural fluid lactate has a high accuracy for diagnosis and management of PPE.