A novel survival rat model of hyperkalemia and landiolol induced cardioplegic arrest and resuscitation via cardiopulmonary bypass

A small animal model would be an effective tool for research on the pathophysiology of cardiopulmonary bypass (CPB). However, numerous CPB models do not involve myocardial arrest and resuscitation. The aim of this research is to establish an easily achievable myocardial arrest and resuscitation CPB model through hyperkalemia and landiolol, simulating clinical cardiac surgery.Ten Sprague-Dawley rats were chosen for CPB. Rats underwent sevoflurane inhalation induction anesthesia and were sustained in an anesthesia state by intubation and intraperitoneal injection's of esketamine and propofol. The entire CPB circuit include a reservoir, a membrane oxygenator and a roller pump, which were connected into a complete loop via silicon tubes and infusion tube.After CPB was established through the tail artery and internal jugular vein, cardioplegic arrest was induced and maintained for 5 min at a rectum temperature of 28.5 ± 0.5°C with hyperkalemia and landiolol. Calcium chloride, epinephrine and insulin were then used for resuscitation.All rats successfully finished cardioplegic arrest, resuscitation procedure and survived 2 h postoperatively. Mean hematocrit during CPB was significantly lower than physiologic values of the baseline. The mean time of arrest-resuscitation and CPB was 5.4 ± 0.8 min and 98.5 ± 5.0 min. The blood gas at each detection point were in range with the normal standard requirement of CPB.The establishment of cardioplegic arrest and resuscitation procedure via hyperkalemia and landiolol during CPB of WD rat could be achieved successfully. This animal model could be an alternative organ injury research on organ injury of patients undergoing cardiac surgery.