Light's criteria

Introduction

Pleural effusions are classified as transudative or exudative.

Exudates have at least 1 of the following, transudates none:

• pleural fluid/serum protein > 0.5
• pleural fluid/serum lactate dehydrogenase > 0.6
• pleural fluid lactate dehydrogenase > 2/3* the upper limit of normal for serum lactate dehydrogenase (LDH)

* More recent data suggests that > 45% the upper limit of normal for serum LDH may be better.

More general terms

• criteria

Additional terms

• pleural effusion