Effects of the administration of 2,3-butanedione monoxime during conventional cardiopulmonary resuscitation on ischaemic contracture and resuscitability in a pig model of out-of-hospital cardiac arrest

Aim of the studyIschaemic contracture compromises the haemodynamic effectiveness of cardiopulmonary resuscitation and resuscitability. 2,3-Butanedione monoxime (BDM) reduced ischaemic contracture by inhibiting actin-myosin crossbridge formation in an isolated heart model. We investigated the effects of BDM on ischaemic contracture and resuscitation outcomes in a pig model of out-of-hospital cardiac arrest (OHCA).MethodsAfter 15 min of untreated ventricular fibrillation, followed by 8 min of basic life support, 16 pigs were randomised to receive either 2 ml kg−1 of BDM solution (25 g l−1) or 2 ml kg−1 of saline during advanced cardiac life support (ACLS).ResultsDuring the ACLS, the control group showed an increase in left ventricular (LV) wall thickness from 10.0 mm (10.0-10.8) to 13.0 mm (13.0-13.0) and a decrease in LV chamber area from 8.13 cm2 (7.59-9.29) to 7.47 cm2 (5.84-8.43). In contrast, the BDM group showed a decrease in the LV wall thickness from 10 mm (9.0-10.8) to 8.5 mm (7.0-9.8) and an increase in the LV chamber area from 9.86 cm2 (7.22-12.39) to 12.15 cm2 (8.02-14.40). Mixed model analyses of the LV wall thickness and LV chamber area revealed significant group effects and group-time interactions. Spontaneous circulation was restored in four (50%) animals in the control group and in eight (100%) animals in the BDM group (p = 0.077). All the resuscitated animals survived during an intensive care period of 4 h.ConclusionBDM administered during cardiopulmonary resuscitation reversed ischaemic contracture in a pig model of OHCA.