Prolonged ventilation after open heart surgery is a risk factor which portends longer ICU stays, increased incurred costs, and poorer physiologic outcomes. This application is used to predict the risk of postoperative mechanical ventilation after open heart surgery, based on the algorithm published by Reddy, et al., in Ann Thor Surg 2007;84:528-36, from the Cardiothoracic Centre - Liverpool, United Kingdom. This calculator is meant for educational and discussion purposes only, and does not substitute for the expertise of healthcare providers.