Incentive spirometry for preventing pulmonary complications after coronary artery bypass graft.

BACKGROUND

Following coronary artery bypass graft (CABG), the main causes of postoperative morbidity and mortality are postoperative pulmonary complications, respiratory dysfunction and arterial hypoxemia. Incentive spirometry is a treatment technique that uses a mechanical device (an incentive spirometer) to reduce such pulmonary complications during postoperative care.

OBJECTIVES

To assess the effects of incentive spirometry for preventing postoperative pulmonary complications in adults undergoing CABG.

SEARCH STRATEGY

We searched CENTRAL on The Cochrane Library (Issue 2, 2004), MEDLINE (1966 to December 2004), EMBASE (1980 to December 2004), LILACS (1982 to December 2004), the Physiotherapy Evidence Database (PEDro) (1980 to December 2004), Allied & Complementary Medicine (AMED) (1985 to December 2004), CINAHL (1982 to December 2004), and the Database of Abstracts of Reviews of Effects (DARE) (1994 to December 2004). References were checked and authors contacted. No language restrictions were applied.

SELECTION CRITERIA

Randomized controlled trials comparing incentive spirometry with any type of prophylactic physiotherapy for prevention of postoperative pulmonary complications in adults undergoing CABG.

DATA COLLECTION AND ANALYSIS

Two reviewers independently evaluated the quality of trials using the guidelines of the Cochrane Reviewers' Handbook and extracted data from included trials.

MAIN RESULTS

Four trials with 443 participants contributed to this review. There was no significant difference in pulmonary complications (atelectasis and pneumonia) between treatment with incentive spirometry and treatment with positive pressure breathing techniques (continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP) and intermittent positive pressure breathing (IPPB)) or preoperative patient education. Patients treated with incentive spirometry had worse pulmonary function and arterial oxygenation compared with positive pressure breathing (CPAP, BiPAP, IPPB).

AUTHORS' CONCLUSIONS: Individual small trials suggest that there is no evidence of benefit from incentive spirometry in reducing pulmonary complications and in decreasing the negative effects on pulmonary function in patients undergoing CABG. In view of the modest number of patients studied, methodological shortcomings and poor reporting of the included trials, these results should be interpreted cautiously. An appropriately powered trial of high methodological rigour is needed to determine those patients who may derive benefit from incentive spirometry following CABG.