Pressão positiva expiratória na via aérea associada ao inspirômetro de incentivo reduz as complicações pulmonares, melhora a função pulmonar e a capacidade funcional em pacientes submetidos à cirurgia de revascularização do miocárdio

Expiratory Positive Airway Pressure Associated with Incentive Spirometry Reduces Pulmonary Complications and Improves Functional Capacity in Patients Undergoing Coronary Artery Bypass Graft Surgery Background: Patients undergoing coronary artery bypass graft (CABG) surgery are at relatively high risk of postoperative pulmonary complications (PPCs), increasing length of hospital stay and resource utilization. The presence of risk factors such as smoke and elderly increases the incidence rate of PPCs. The basic mechanism of PPCs is a lack of lung inflation due to a shallow, monotonous breathing pattern without periodic sighs. The use of the expiratory positive airway pressure (EPAP), associated with incentive spirometry (IS) for the prevention of PPCs following CABG is not well established. Therefore, we hypothesized that EPAP+IS protocol reduces the PPCs and increases submaximal functional capacity, assed by the distance covered during the 6-min walk test. Methods: Thirty four patients undergoing CABG with previous smoking history were randomly assigned to a placebo group (n=17) or to a program of EPAP+IS during hospital stay, which was followed at home to complete thirty days (n=17). Pulmonary function test, maximal inspiratory and expiratory mouth pressures, 6min walk test and thoracic radiological evaluation were performed at baseline, day 7 and day 30. Results: Both groups were comparable at baseline. Radiological injury score at day 7 was lower in EPAP+IS compared to the placebo group (1.94±0.8 vs 4.01±1.9; P<0.004). The distance walked in the 6-min test was higher at day 30 in EPAP+IS group (428.4±64.2 vs 335.8±93.2 m; P<0.001). The EPAP+IS group improved maximal expiratory pressure at day 30 (102.7±26.4 cmH2O) compared to day 7 (82.2±20.9 cmH2O; P<0.01). Maximal inspiratory pressure was better improved in the EPAP+IS group compared to the placebo group (day 7: -80.3±23.3 vs -63.7±12.9; day 30: -100.3±26.6 vs -64.6±35.5 cmH2O; P<0.001). Inspiratory capacity was higher in day 30 in EPAP+IS group compared to the placebo group (2.4±0.6 vs 1.9±0.5 L; P<0.05). Furthermore, on day 30, forced vital capacity (78.2±14.2 vs 68.7±14.2 % of predicted; P<0.05) and forced expiratory volume in 1 second (79.7±16.6 vs 68.0±16.1 % of predicted; P< 0.05) was higher in EPAP+IS compared to the placebo group. Conclusions: In patients submitted to a CABG, EPAP+IS protocol for 30 days results in a reduction of PPCs and in an improvement of submaximal functional capacity.