Effect of Recumbent Body Positions on Dynamic Lung Function Parameters in Healthy Young Subjects

The change in body position can alter pulmonary functions parameters, therefore it is important to understand the physiological basis of these alteration. Ideally, spirometry is done in sitting position until the subject is unable to do so. Hospitalized patients often assume recumbent body positions irrespective of underlying pathology. Hence, need arises to find out best recumbent body positions for the benefit of these patients to make breathing comfortable for them.

The aim of this study was to find out whether the change from the supine position to crook lying and Fowler's position (45° dorsal elevation) causes change in spirometric parameters.

The present work was carried out at Department of Physiology, King George's Medical University, Lucknow. A total 131 apparently healthy individuals were enrolled in this cross-sectional study. Lung function was assessed using a PC-based spirometer according to American Thoracic Society guideline in the supine, crook lying and Fowler's position (45° dorsal elevation).

The study consisted of 131 subjects (male 66%, female 34%), with mean age of 20.15±2.71 years and BMI 21.20±3.28 Kg/m². Repeated measures ANOVA with post hoc Bonferroni test was used to compare the mean values between each body position. Compared with the other two positions, Fowler's position showed significantly (p<0.05) higher values for FVC, FEV₁, PEF, FEF_25-75%.

Recumbent body position influences spirometric parameters in young healthy subjects. We demonstrated that spirometric values are higher in the Fowler's position than in the supine or crook lying position. The results of this study will help in the selection of the best alternative position for the spirometry in bed ridden patients.