The Risk Factors of Prolonged Mechanical Ventilation after Isolated Coronary Artery Bypass Graft Surgery

Background: Failure to wean a patient from mechanical ventilation after cardiac surgery is associatedwith poor outcome.Aim: The present study was performed aimed to investigate the risk factors of prolonged mechanicalventilation (PMV) following isolated coronary artery bypass graft (CABG) surgery.Method: This retrospective cohort study was performed on ۲۱۵۵ consecutive adult patientsundergoing isolated coronary artery bypass graft surgery (May ۲۰۱۲ to November ۲۰۱۶ at Imam Rezahospital, Mashhad, Iran). The subjects were assessed for duration of weaning from mechanicalventilation, predictive risk factors for prolonged mechanical ventilation and associated outcomesincluding intensive care unit (ICU) and hospital length of stay (LOS), and mortality. Data wereanalyzed by SPSS (version ۲۲). P<۰.۰۵ was considered statistically significant.Results: The median (۲۵ -۷۵ percentile) duration of mechanical ventilation was ۳۶۰ (۲۲۵-۵۴۰)minutes. Also, ۵۱.۲۰%, ۴۵.۸۰% and ۲.۳۰% patients were weaned from mechanical ventilation in lessthan ۶ hours, ۷ to ۲۴ hours, and more than ۲۴ hours, respectively. Cerebral vascular accident was themost common cause of PMV (۳۴.۰۴%). After adjustment for confounder variables, on-pump CABG(P<۰.۰۵), duration of surgery (P<۰.۰۱), preoperative renal failure (P<۰.۰۵) and New York HeartAssociation (NYHA) class ۴ were associated with PMV (P <۰.۰۵). PMV was associated withincreased length of ICU and hospital stay (P<۰.۰۱). There was a higher mortality rates in patients withPMV (P<۰.۰۰۱).Implications for Practice: Most patients are weaned from mechanical ventilation within ۲۴ hoursuneventfully after isolated CABG. Furthermore, on-pump CABG, prolonged surgery, preoperativerenal insufficiency, and NYHA class ۴ were independent predictors of prolonged mechanicalventilation. Identifying the risk factors causing PMV can prevent its adverse consequences.

Keywords:

coronary artery bypass graft surgery , Mechanical Ventilation , weaning