A comparison of breathing exercises, incentive spirometry and mobilisation after coronary artery surgery

Abstract

We compared early mobilisation (sitting in a chair and walking on the second post-operative day) and instruction in huffing and coughing alone, and in conjunction with breathing exercises or incentive spirometry as methods of restoring lung function to pre-operative values and preventing chest infection in patients undergoing coronary artery bypass grafting. A total of 131 pre-operative males were randomly allocated to receive one of the three treatments. All of the patients were seen by a physiotherapist prior to surgery and for the first 5 post-operative days. Lung function, including functional residual capacity (FRC) and blood gas tensions, was measured on the ward before and after operation. A daily assessment of chest discomfort was recorded on a visual analogue scale and the distance walked each day was noted. There were no significant differences between the groups at the start of the study or at any time after operation. On the second day, FRC and vital capacity (VC) were only 61 and 39% (mean values) of their pre-operative (pre-op) values and the mean arterial oxygen tension (PaO₂) was 7.37 kilopascals (kPa) (mean pre-op PaO₂ was 10.56 kPa). Although lung volumes increased daily, on day 5 FRC and VC were only 76 and 63% pre-op, respectively (mean values). No treatment was superior in restoring lung function or in preventing chest infection.