Fig. 1
The timeline of events. T 1 5 min before beginning of surgery, T 2 5 min after heparin was reversed by protamine, T 3 at the end of surgery, T 4 at 24 h after end of surgery. Perioperative period (peri-op) the period from beginning of anesthesia to 24 h after end of surgery. Postoperative period (post-op) the period from the end of surgery to 24 h after end of surgery. The period of heparinization: the period from blood anticoagulated by heparin to heparin were reversed by protamine. The period of non-heparinization: the period from beginning of surgery to blood anticoagulated by heparin + the period from heparin were reversed by protamine to end of surgery