The Usefulness of Pleural Lactate Measurement for Differentiating Transudate and Exudate

Creative Commons License

Çevlik R., Özakın E., Yıldırım H., Genç E., Acar N., Baloğlu Kaya F., ...More

Osmangazi Tıp Dergisi, vol.43, no.3, pp.217-223, 2021 (Peer-Reviewed Journal) identifier

  • Publication Type: Article / Article
  • Volume: 43 Issue: 3
  • Publication Date: 2021
  • Doi Number: 10.20515/otd.750745
  • Journal Name: Osmangazi Tıp Dergisi
  • Journal Indexes: TR DİZİN (ULAKBİM)
  • Page Numbers: pp.217-223
  • Eskisehir Osmangazi University Affiliated: Yes


Our study aimed to evaluate pleural lactate levels, to identify the reliability and validity of determining pleural fluid quality in patients with pleural effusion.This is a prospective, observational study conducted on patients who were admitted to a university hospital between July 1, 2017, and January 31, 2018, and diagnosed with pleural effusion. Pleural fluid classification into transudates and exudates was made according to Light’s criteria. The study group consisted of a total of 169 patients with pleural effusion, [99 (58.6%) male and aging 18-93 years (mean ± SD, 64.6 ± 16.1 years)]. Forty-four (26%) of the patients were evaluated as exudate and 125 (74%) as transudate. The median value of lactate was 3.20 mmol/L (min-max: 0.90-14.3) in exudate patients and 1.85 mmol/L (min-max: 0.90-4.70) in transudate patients, and a significant difference was detected in the comparison of both (z: 5.894; p<0.001). There was a positive correlation between pleural lactate levels and pleural LDH, pleural LDH/serum LDH and pleural protein/serum protein ratios. The cut-off value of the pleural fluid lactate level was determined to be 2.0 for the highest sensitivity and specificity (sensitivity: 85%, specificity: 64%; AUC: 0.799). Measurement of lactate levels in pleural fluid can be useful for the differentiation of transudate and exudate fluid. Moreover, detection of lactate levels in a very short period may provide a more useful screening tool compared to other strategies.