Weaning of chronic obstructive pulmonary disease patients after coronary artery bypass graft surgery

Abstract

Background Cardiac surgery has become more common in chronic obstructive pulmonary disease (COPD) patients, but this category is still at a high risk of postoperative prolonged ventilation. Finding of the appropriate mode for faster weaning is important to improve a patient’s outcome. Objective This study aimed to evaluate the effect of adaptive support ventilation (ASV) as a weaning mode in comparison with the pressure support mode in COPD patients in the postoperative period after a coronary artery bypass grafting (CABG) surgery. Patients and methods A randomized-controlled trial was conducted on 90 COPD (stage I and II) patients between 40 and 65 years old in the postoperative cardiothoracic ICU after CABG surgeries. Patients were initially ventilated with synchronized intermittent mandatory ventilation and were then allocated randomly to two equal groups to wean either by ASV group or pressure support ventilation group. The primary outcome was the number of patients weaned successfully from the first trial. The secondary outcomes were duration of mechanical ventilation, duration of weaning, number of arterial blood gas samples before extubation, length of ICU stay, cardiac and respiratory parameters at extubation, and mortality. Result In the ASV group, significantly higher numbers of patients were weaned from first trial, there was a shorter duration of weaning and mechanical ventilation and ICU stay, with fewer times of manual ventilator adjustments and arterial blood gas samples drawing during weaning. At extubation, this group showed a significantly lower respiratory rate, higher tidal volume, and lower peak airway pressure, with less tachycardia and lower systolic blood pressure compared with the pressure support ventilation group. Conclusion The ASV mode improves the quality of weaning and shortens ICU stay in COPD patients after CABG surgery.