Introduction:

pleural effusion is caused by an imbalance between oncotic and hydrostatic pressure through the pulmonary capillaries or by increased permeability. Ultrasound at the patient’s bedside allows for efficient diagnosis in various areas, due to its portability and low cost, enabling the quantification of pleural fluid, determination of its characteristics, and guidance for percutaneous drainage. Post cardiac surgery, large pleural effusions can affect the patient’s recovery journey.

Material and methods:

we conducted a cross-sectional study of 26 nonconsecutive adult patients who underwent cardiac surgery in whom pleural effusion was detected by ultrasound in the postoperative period. The pleural effusion volume, quantified by Balik’s formula, correlated with the amount of pleural fluid drained. In addition, the characteristics of the fluid were defined to determine any correlation with Light’s criteria.

Results:

there was a strong positive correlation between the volume quantified by Balik’s formula and the amount of pleural fluid drained. We also found that the characteristics of drained pleural effusion, as determined through ultrasound, had sufficient diagnostic accuracy to differentiate between transudate and exudate compared with Light’s criteria.

Conclusions:

there is a strong positive correlation between the fluid volume quantified by ultrasound with Balik’s formula and the volume drained in the postoperative period of cardiac surgery, in addition to high diagnostic accuracy in the identification of the fluid as transudate or exudate.