Abstract: Abstract: Objective To systematically evaluate the risk factors of prolonged mechanical ventilation after coronary artery bypass grafting. Methods PubMed, EMBASE, Cochrane Library, Web of Science, ClinicalTrials. gov, CNKI, Wanfang and VIP were systematically searched for case-control studies or cohort studies on factors associated with prolonged mechanical ventilation following coronary artery bypass grafting. According to Cochrane system evaluation method, the quality of the research literatures meeting the inclusion criteria was evaluated. The adjusted odds ratio (OR) and 95%CI were extracted, and the RevMan5.3 software was used for Meta analysis. Results Seven literatures were included in the study, including 5 336 patients. The correlation between prolonged mechanical ventilation following coronary artery bypass grafting and demographic factors was studied, including age, gender, body mass index, preoperative factors (left ventricular ejection fraction, chronic obstructive pulmonary disease and renal dysfunction), intraoperative factors (operative time) and postoperative factor (reoperation). Meta-analysis revealed that older age (OR=1.06, 95%CI: 1.05-1.07), female (OR=1.92, 95%CI: 1.37-2.68), renal dysfunction (OR=2.35, 95%CI: 1.41-3.90), longer operative time (OR=1.50, 95%CI: 1.22-1.85) and reoperation (OR=9.56, 95%CI: 3.65-25.00) were the independent risk factors for prolonged mechanical ventilation after coronary artery bypass grafting, and higher left ventricular ejection fraction (OR=0.97, 95%CI: 0.95-0.99) was the protective factor. There was insufficient evidence to confirm the correlation between body mass index (OR=0.95, 95%CI: 0.68-1.32), chronic obstructive pulmonary disease (OR=3.94, 95%CI: 0.68-22.81) and prolonged mechanical ventilation after coronary artery bypass grafting. Conclusion Results suggest that older age, female, preoperative lower left ventricular ejection fraction, preoperative renal dysfunction, longer operative time and reoperation are the independent risk factors for prolonged mechanical ventilation after coronary artery bypass grafting. This study provides theoretical support for the prevention and risk prediction model of prolong mechanical ventilation after coronary artery bypass grafting.

Key words: coronary artery bypass, off-pump, respiration, artificial, risk factors, Meta-analysis, prolong mechanical ventilation