Background: Pleural effusion is an abnormal accumulation of fluid in the intra-pleural space. The relative annual incidence of pleural effusion is estimated to be 320 per 100,000 people in industrialized countries. In pleural effusion positioning may be used to optimize gas-exchange. The therapeutic body positioning is a primary non-invasive physical-therapy intervention. Methodology: The presence of pleural effusion was assessed by physical examination and chest X-ray. Pulmonary function testing (RMS HELIOS Spirometer) was conducted in sitting, right and left lateral decubitus positions. A forced expiratory maneuver was performed three times in each position after maintaining that position for 20 minutes and with rest as needed by the patient, between trials. It was made sure that subjects understood the instructions and performed the test with standard guideline (ATS Guidelines). The best values of forced vital capacity (FVC) and forced expiratory volume (FEV) were analyzed. Results: No significant difference (p >0.10) was noted in FVC, FEV1 and FEV1/FVC values between the three positions. Although, mean values of FVC, FEV1 in sitting position (41.6 ± 12.20) was higher than mean value of FVC, FEV1 of lateral positions. In lateral decubitus position the mean FVC, FEV1 value of effusion lung upper most (37.8 ± 11.50) was slightly higher than effusion lung dependant (36.5 ± 12.8). Conclusion: Position does not appear to have a significant effect on PFT in unilateral effusion patients.

Keywords: Pleural effusion, PFT (pulmonary function test), body position.