Anaesthetics alter the magnitude of infarct limitation by ischaemic preconditioning

84 anesthetized open chest rabbits undergoing a 30 min coronary occlusion followed by 3 h reperfusion

Ischemic preconditioning (5 min coronary occlusion beginning 15 min before the 30 min coronary occlusion) under three different anesthetics: pentobarbitone (30 mg/kg IV + 30-50 mg/kg/h IV), isoflurane (1.5-2.5% end expiratory), or ketamine/xylazine (67 mg ketamine and 6.7 mg xylazine/ml, 1 ml/kg IM + 0.3-1.3 ml/kg/h IM)

Non-preconditioned hearts under the same anesthetic regimens

Infarct size limitation (assessed with tetrazolium)surrogate