Objective: Pulmonary complications following cardiac surgery through sternotomy are well known, but little is known about the proposed alterations of the chest wall mechanism. The purpose of this study was to examine changes in chest wall motion and pulmonary function after cardiac surgery.
Design: The subjects were 20 cardiac surgery patients, 13 men and 7 women, mean age 65 years.
Measurements: Bilateral respiratory movements were measured using the Respiratory Movement Measuring Instrument before, 3 and 12 months after the operation. Vital capacity (VC), forced vital capacity (FVC) and forced expiratory volume (FEV1) were measured with the Pulminet III (Gold Godart Ltd Vitalograph Alpha Ltd. Maids Morton, Buckingham, England) preoperatively, 3 and 12 months postoperatively, and radiographs were taken at the same points in time.
Analysis: Descriptive statistics, paired sample t-tests, Mann-Whitney and Wilcoxon Signed Rank tests were used for analyses, p < or = 0.05.
Results: Average abdominal movements 3 months postoperatively were significantly decreased and the difference between right and left side in upper thoracic and abdominal movements was significant. All pulmonary function measurements except the FEV1/FVC showed a significant decrease and a restrictive pattern compared with preoperative values. Twelve months after the operation the upper thoracic movements were significantly increased. Five patients had an abnormal chest x-ray before the operation, eight 3 months and three 12 months after the operation.
Conclusion: The motor system of the respiratory organs suffers considerable injury from cardiac surgery, which in part at least can explain the restrictive breathing 3 months postoperatively.