Clinical Trial Summary
The rate of pulmonary complications following Coronary artery bypass graft (CABG) is high.
Early pulmonary exercises are important in preventing this complication following cardiac
surgery. This study aimed to investigate the effectiveness of incentive spirometer (IS) and
diaphragmatic breathing exercise (DBE) on the alteration of arterial blood gas (ABG)
measures. The study was based on a two-arm, parallel-group, randomized comparative design.
Thirty patients who underwent CABG enrolled in the study based on inclusion and exclusion
criteria, randomly allocated into either of the groups, IS Group or DBE Group. IS Group and
DBE Group underwent chest physiotherapy with IS and DBE, respectively. ABG measures,
including PH of blood, partial pressure of arterial oxygen molecule (PaO2), and partial
pressure of arterial carbon dioxide (PaCO2), was assessed using an ABG analyzer at baseline
(pre-operation), day1 post-operation, and day2 post-operation. The significance level was
kept constant for all statistical analyses at 95%.
Coronary artery bypass graft (CABG) is one of common treatment procedures performed
worldwide. Evidence suggest that every year more than 1 million CABG procedure has been
performed. Pulmonary complications are one of the most common consequence post CABG.
The incidence of atelectasis after heart operation with cardiopulmonary bypass is still
80-84% in spite of careful fluid & respiratory management. The basic problem in respiratory
care of post-surgical patient is atelectasis leading to hypoxemia causing alteration in
arterial blood gases (ABGs). Associated with atelectasis are widening alveolar - arterial O2
gradient (as right to left intrapulmonary shunting increases) decrease ventilation perfusion
ratio, decrease functional residual capacity and decrease compliance. Chest physiotherapy is
routinely used after major abdominal & cardiothoracic surgery to prevent these pulmonary
complications following operation.
To date, there is a variable view about the effectiveness of these two primary breathing
exercise techniques (incentive spirometer and diaphragmatic breathing exercise). 10-12 Hence
an effort to systematically study the effectiveness of these is attempted. Thus, the current
study aimed to determine the efficacy of incentive spirometer and diaphragmatic breathing
exercises in addition to conventional chest physiotherapy on alteration of ABG measures in
patients with post CABG. This study hypothesized that there will be a significant difference
between the effect of the IS and DBE on ABG alteration in post CABG patients.