Changes in Pulmonary Compliance in Patients Undergoing Cardiac Surgery

Abstract

Dynamic pulmonary compliance was measured during normal and deep breathing in patients undergoing cardiac surgery. Prior to surgery, different groups of patients had varying responses to deep breathing. Patients with pulmonic stenosis showed decreases in the compliance with deep breathing, patients with mitral stenosis showed increases and patients with atrial septal defects and ventricular septal defects showed intermediary changes in the compliance. The response of the compliance to deep breathing postoperatively tended to be more uniform and most groups of patients showed a slight increase in the compliance with deep breathing. Thoracotomy tended to lower compliance significantly. Patients undergoing seclusion of ventricular or atrial septal defects had changes in the compliance which could be attributed to the thoracotomy alone. In the patients with commissurotomy of the pulmonary valve, the decrease in the compliance was much greater than the decrease that could be attributed to thoracotomy, and in patients with mitral commissurotomies, the change attributable to thoracotomy was offset by an increase in compliance. Average left atrial pressures in the various groups of patients correlated well with the behavior of the compliance in response to deep breathing and surgery.