[Comparative study between intermittent (Müller Reanimator) and continuous positive airway pressure in the postoperative period of coronary artery bypass grafting]

Abstract

Objective: To compare the effect of the use of intermittent and continuous positive airway pressure in postoperative patients undergoing coronary artery bypass grafting.

Methods: This study included forty patients divided into two groups: one undergoing continuous positive airway pressure (CPAP Group), and the other undergoing intermittent pressure (Müller Resuscitator Group). The patients were evaluated in relation to the several study variables at the following time points: preoperative, 3rd, 24th, and 48th hours.

Results: The patient groups were homogeneous in relation to the several demographic and clinical variables. The values of pO2, pCO2 and sO2 were within normal limits and no significant differences were found between the groups. Regarding respirometry, the groups showed significant differences in the tidal volume and respiratory rate at the 48th postoperative hour. Dyspnea and use of accessory muscle in postoperative assessments were found with a significantly higher frequency in patients undergoing CPAP. Patients undergoing Müller Resuscitator had a normal chest radiograph more frequently than did patients undergoing CPAP.

Conclusion: Both devices were shown to be able to keep pO2, pCO2, and sO2 values within normal limits. However, when the objective was pulmonary reexpansion with less imposed workload, the Müller Resuscitator was more effective because of its prompter action and consequently lower levels of dyspnea, respiratory rate (RR) and use of accessory muscle were observed.