Prophylactic respiratory physiotherapy after cardiac surgery: systematic review

To assess whether respiratory physiotherapy prevents pulmonary complications after cardiac surgery.

Searches through Medline, Embase, Cinahl, the Cochrane library, and bibliographies, for randomised trials comparing any type of prophylactic respiratory physiotherapy with another type or no intervention after cardiac surgery, with a follow up of at least two days, and reporting on respiratory outcomes.

Investigators assessed trial validity independently. Information on study design, population, interventions, and end points was abstracted by one investigator and checked by the others.

18 trials (1457 patients) were identified. Most were of low quality. They tested physical therapy (13 trials), incentive spirometry (eight), continuous positive airway pressure (five), and intermittent positive pressure breathing (three). The maximum follow up was six days. Four trials only had a no intervention control; none showed any significant benefit of physiotherapy. Across all trials and interventions, average values postoperatively were: incidence of atelectasis, 15-98%; incidence of pneumonia, 0-20%; partial pressure of arterial oxygen per inspired oxygen fraction, 212-329 mm Hg; vital capacity, 37-72% of preoperative values; and forced expiratory volume in one second, 34-72%. No intervention showed superiority for any end point. For the most labour intensive intervention, continuous positive airway pressure, the average cost of labour for each patient day was 27 euro (pound 19; 32 dollars).

The usefulness of respiratory physiotherapy for the prevention of pulmonary complications after cardiac surgery remains unproved. Large randomised trials are needed with no intervention controls, clinically relevant end points, and reasonable follow up periods.