Influence of Thoracotomy on Pulmonary Mechanics

Abstract

Dynamic pulmonary compliance, non-elastic resistance and work of breathing were calculated from pressure-volume loops in 22 thoracic surgical patients. Work of breathing increased progressively duringthoracetomy in most patients, probably as a result of accumulated bronchial secretions and atelectasis: as these secretions were cleared and deep breathing resumed, work of ventilation returned to normal. Post-operative respiratory complications were frequent among patients whose work of breathing was above the mean for the group at the conclusion of the thoracotomy. Pulmonary compliance decreased progressively to a low value immediately after closure of the thoracotomy. Mean non-elastic resistance decreased with intubation, then increased during the remainder of the procedure. Work of breathing was lowest immediately after intubation and increased during the procedure as changes in compliance and non-elastic resistance contributed to increase in work. Postoperative studies indicated that the lungs and airway had returned to preoperative status during the month after thoracotomy.