Chest physiotherapy a physiological assessment during intermittent positive pressure ventilation in respiratory failure

Abstract

Six patients in respiratory failure who were receiving intermittent positive pressure ventilation were studied to determine the efficacy of chest physiotherapy and the nature of the accompanying cardiovascular changes. Arterial to alveolar tension gradients for both oxygen and carbon dioxide were measured before and after chest physiotherapy, as was cardiac output. In addition, serial cardiac output measurements were made during physiotherapy. No overall change in pulmonary gas exchange was demonstrated. Cardiovascular response varied in different patients; a rise or a fall by as much as 50 per cent of the initial cardiac output was observed. The results are discussed and it is suggested that further study is needed to define which of those procedures used during chest physiotherapy are effective and safe. © 1969 Canadian Anesthesiologists.