Changes in total lung/thorax compliance following chest physiotherapy

To quantitate and obtain objective assessment of the effect of secretion clearance following chest physiotherapy (CPT), total lung/thorax complicance (CT) was calculated immediately before and for 2 hours after one treatment with CPT. Forty-two patients who were mechanically ventilated because of respiratory failure were studied. Therapy averaged 57 minutes and included postural drainage, percussion, vibration, and endotracheal suctioning. The increase in CT following CPT was statistically significant (p less than 0.01) and remained so for at least 2 hours after CPT. There was no difference in the degree to which CT changed in patients with different indications for CPT or in patients ventilated with positive end-expiratory pressure. Largest mean values for CT were obtained 2 hours following CPT, the duration of our measurement of CT. Chest x-ray identification of affected areas of lung before CPT is necessary to allow the physiotherapist to produce the CT changes noted in this study. CT, which can be readily calculated from many recently designed ventilators, may be monitored during CPT to evaluate the efficacy of treatment and to quantitate the effect of secretion clearance following CPT. Duration of CPT should be determined by CT and auscultation.