Cardiorespiratory function before and after chest physiotherapy in mechanically ventilated patients with post-traumatic respiratory failure.

Chest physiotherapy (CPT) is used frequently in the ICU, but there is little available information that quantitates its effect on cardiac or respiratory function. Nineteen mechanically ventilated patients with post-traumatic respiratory failure were studied before, immediately after, and 2 h after CPT was used to manage secretion retention. Cardiac index was unchanged, but there was an immediate decrease in intrapulmonary shunt, followed 2 h later by an increase in lung/thorax compliance. We did not find the reduced cardiac output reported by others. The reasons for this may include use of different CPT techniques, a young patient population (mean age 32.4 yr), and mechanical ventilation with positive end-expiratory pressure. CPT did not produce the deleterious cardiopulmonary changes associated with bronchoscopy, and it reduced retained lung secretions without producing hypoxemia. Intrapulmonary shunt and lung/thorax compliance were significantly improved, but the long-term clinical effect of these changes is unknown.