Rabbit CPB model

All surgical procedures in this study were performed under general anesthesia and continuous monitoring of heart rate, 3-lead electrocardiography, arterial blood pressure, and oxygen saturation. After inducing anaesthesia with intramuscular ketamine (25 mg/kg) and xylazine (10 mg/kg), followed by intravenous injection of pentobarbital (15 mg/kg), animals underwent tracheotomy, followed by endotracheal intubation, and were connected to a mechanical ventilator. General anaesthesia was maintained with continuous inhalation of isoflurane (2–3%) during the procedure. The right femoral artery and vein were exposed and cannulated with a 20-gauge catheter for monitoring blood pressure and as a route of drug infusion, respectively. The CPB circuit composed of polyvinyl chloride tubing, a venous reservoir, and an oxygenator (Excelung Kids, HPO-06RHF-CP; MERA, Tokyo, Japan) was driven by a roller head pump (MERA) (Fig. 6B). The priming solution of the circuit consists of 50 mL of 25% human albumin solution (Albuminar; CSL Behring, Tokyo, Japan), 40 mL of washed red blood cells (RBCs) collected from a donor rabbit, 0.5 mL (500 IU) of heparin sodium injection, and 159.5 mL of normal saline (total volume, 250 mL). Thereafter, median sternotomy was performed and the pericardium was opened. After injecting 0.5 mL (500 IU) of heparin sodium, an 8-Fr arterial cannula was introduced into the ascending aorta and a 10-Fr venous cannula was placed in the right atrium through the right atrial appendage (Fig. 6A). These cannulas were connected to the CPB circuit and a normothermic CPB run was maintained for 60 min at a flow rate of 80–100 mL/kg/min (Fig. 6C). After weaning and termination of the CPB run, protamine sulphate (10 mg) was administered and the cannulas were removed. RBCs remaining in the CPB circuit were collected and re-administered to ameliorate severe anaemia and ensure survival.

A rabbit model of cardiopulmonary bypass coagulopathy. (A) Cannulas in the ascending artery and right appendage are connected to the tube. (B) The cardiopulmonary bypass machine. (C) Experimental design of the current study. CPB, cardiopulmonary bypass; PPP, platelet-poor plasma; PRP, platelet-rich plasma.