[Determinants of prolonged mechanical ventilation after cardiac surgery]

This study aimed to examine factors that delay weaning from ventilation after cardiac surgery.

A retrospective examination was made on 1,033 patients who had undergone cardiac surgery through a midsternal incision between January 2009 and July 2011. The items examined were duration of postoperative ventilation, patient's background, and other surgical information. If patients were weaned within 24 hours from intensive care unit (ICU) admission, they were included in the timely weaning group. If patients required 24 hours or more to be weaned, they were included in the delayed weaning group.

There was a relationship between prolonged ventilation and the following factors: emergency surgery, history of arrhythmia, history of motor system disorder, preoperative estimated glomerular filtration rate (eGFR), preoperative New York Heart Association (NYHA) classification, preoperative left ventricular ejection fraction (LVEF), operative method, operative time, blood loss, intraoperative fluid management, and number of days from surgery until achievement of independent gait. The independent factors delaying extubation were emergency surgery, preoperative NYHA classification, preoperative LVEF, operative method, operative time, blood loss, and intraoperative fluid management(p<0.05).

Surgical invasiveness and preoperative heart failure were involved in the prolonged ventilation after cardiac surgery.