RESUMO

Objective. We sought to determine the effect of threshold inspiratory muscle training (IMT) on maximum inspiratory pressure (MIP), pulmonary gas exchange and atelectasis in patients undergoing coronary revascularization. Design. Overall, 33 male patients were randomly assigned into intervention group (17 patients) and control group (16 patients). Both groups received customary physical therapy care. The intervention group received threshold IMT using an inspiratory threshold-loading device preoperatively, postoperatively (for 15 minutes twice daily) and during the intensive care unit stay (30 deep breaths, twice daily) against resistance equal to 30% of MIP. The workload was increased or decreased based on the patient's perception of exertion or fatigue using the Borg CR10 scale. MIP, oxygen saturation, and atelectasis (by calculating the alveolar-arterial oxygen [A-a] gradient) were assessed perioperatively. Result. Before hospital discharge, the MIP and SpO2 in the intervention group were significantly higher in the intervention group than in the control group. In the intervention group, the A-a gradient was lower than that in the control group immediately after surgery and after 40 hours. Conclusion. IMT caused an increase in both MIP and SpO2 and a decrease in the A-a gradient, achieving an improvement in gas exchange and a reduction in atelectasis after coronary revascularization surgery.