Pulmonary function 4 months after coronary artery bypass graft surgery

The objective of this study was to describe the pulmonary function and pain 4 months after coronary artery bypass graft surgery. Twenty-five male patients performed pulmonary function tests before surgery, on the 4th postoperative day and 4 months after surgery. A severe reduction in pulmonary function was present after surgery. Four months postoperatively, the patients still showed a significant decrease (6-13% of preoperative values) in vital capacity (P<0.001), inspiratory capacity (P<0.001), forced expiratory volume in 1 s (P<0.001) peak expiratory flow rate (P<0.001), functional residual capacity (P=0.05) total lung capacity (P<0.001) and single-breath carbon monoxide diffusing capacity (P<0.01). Residual volume and single-breath carbon monoxide diffusing capacity per litre of alveolar volume had returned to the preoperative level. Four months postoperatively, the median values for sternotomy pain while taking a deep breath was 0.2 and while coughing 0.3 on a 10 cm visual analogue pain scale. In conclusion, a significant restrictive pulmonary impairment persisting up to 4 months into the postoperative period was found after CABG. Measured levels of pain were low and could not explain the impairment.