Effects of an inspiratory muscle rehabilitation program in the postoperative period of cardiac surgery.

BACKGROUND Respiratory muscles are affected after cardiac surgeries. OBJECTIVE To verify whether the preoperative conditioning of the inspiratory muscles might help to decrease postoperative respiratory dysfunction. METHODS Thirty volunteers of both genders and with a minimum age of 50 years, while waiting for myocardial revascularization and/or cardiac valve surgery, were randomly assigned to two groups. Fifteen patients were included in a domiciliary program of at least 2 weeks of preoperative training of the inspiratory muscles, using a device with a load corresponding to 40% of the maximum inspiratory pressure. The other 15 patients received general advice and did not train the inspiratory muscle. Spirometry, before and after the training program, as well as the evolution of the arterial blood gases and of the maximum inspiratory and expiratory pressure, before and after the operation were evaluated in both group. The clinical outcomes of the two groups were also compared. RESULTS We observed that inspiratory muscle training increased the forced vital capacity, the maximum voluntary ventilation and the ratio between the forced expired volume during the first second and the forced vital capacity. The evolution of the arterial blood gases and of the maximum inspiratory and expiratory pressures before and after the operation was similar in both groups, with the outcomes also being similar. CONCLUSION We concluded that our domiciliary program of inspiratory muscle training was safe and improved the forced vital capacity and the maximum voluntary ventilation, although the clinical benefits of this program were not clearly demonstrable in the present study.