Chest, Vol 69, 174-178, Copyright © 1976 by American College of Chest Physicians

ARTICLES

Chest physiotherapy and the distribution of ventilation

CJ Martin, H Ripley, J Reynolds and F Best

The injured or postoperative thorax is commonly treated with physiotherapy employing "unilateral breathing" techniques. The ability of these methods to alter the distribution of ventilation and blood flow (oxygen uptake) was examined in four patients undergoing bronchospirometry. No change was observed in these measurements in the lung toward which efforts were being directed to either enhance or restrict the mechanics of breathing. To further examine the problem, two susceptible subjects were hypnotized following intubation for bronchospirometry, and emotional and physical states were suggested that limit motion in one hemithorax. This included the presence of pleuritic pain in one subject who had ample experience with this symptom. In no instance did we find a change in the distribution of ventilation or blood flow to the lung that was supposed to be limited; however, in 17 subjects, lying on one side produced a significant increase in ventilation and blood flow in the dependent lung. Lying on one side or the other consistently and predictably modified ventilation and blood flow, while attempts to produce similar changes by voluntary intention or commonly applied mechanical aids were ineffective.