Short-term changes in pulmonary function and respiratory movements after cardiac surgery via median sternotomy

Abstract

OBJECTIVE--To study the changes in bilateral respiratory motion and pulmonary function following sternotomy and the relationships between the changes in respiratory movements, spirometry, radiographic analyses, and several intra-operative surgical characteristics. DESIGN--Respiratory motion during deep breathing and lung volumes were measured in 20 patients (mean age 65 years, SD 16) before and after median sternotomy. Chest x-rays were analyzed pre- and postoperatively and a variety of perioperative variables were measured. RESULTS--Average abdominal motion decreased to 57% of preoperative values bilaterally 1 week postoperatively, the average lower thoracic motion decreased to 72%, and the average upper thoracic motion decreased to 87%, whereas the right upper thoracic motion increased 3% compared with preoperative values. Lung volumes decreased to around 60% of preoperative values (p<0.05). Significant correlations were found between the decrease in pulmonary function and the mean respiratory movements. Abnormal chest radiographs were found in all patients. CONCLUSION--The breathing pattern before sternotomy is predominantly abdominal but moves to a thoracic and upper thoracic pattern postoperatively and is associated with reduced pulmonary function. Therapeutic interventions aimed at correcting the less effective upper thoracic breathing pattern should likely be implemented.