The effect of body position on pulmonary function: a systematic review

Area of Science:

• Pulmonary Medicine
• Physiology

Background:

• Pulmonary function tests (PFTs) are typically conducted upright for convenience.
• This review examines how body position affects lung function in various populations.

Purpose of the Study:

• To systematically review the influence of body position on lung function.
• To compare lung function measurements across different positions in healthy individuals and patient groups.

Main Methods:

• Systematic literature search (1998-2017) using MEDLINE and Google Scholar.
• Inclusion of studies comparing at least two positions (including sitting/standing) in non-mechanically ventilated adults.
• Analysis of key PFT parameters like FEV1, FVC, FRC, and DLCO across positions such as sitting, standing, and supine.

Main Results:

• Forty-three studies were included, covering healthy subjects and patients with lung, heart, SCI, neuromuscular diseases, and obesity.
• Erect positions generally yielded higher FEV1, FVC, FRC, PEmax, PImax, and PEF in most groups.
• Supine position showed higher FVC and FEV1 in tetraplegic SCI patients compared to sitting; DLCO varied by position and condition.

Conclusions:

• Body position demonstrably influences PFT outcomes, with optimal positions varying by population.
• The supine position is recommended alongside sitting for PFTs in SCI and neuromuscular disease patients.
• Pulmonary physiology is position-dependent, a crucial consideration in clinical practice for affected patient groups.