Effect of bundle of care at early stage of post-cardiac arrest syndrome in rabbits

doi:10.3969/j.issn.1002-1949.2014.12.019

Abstract：Objective To investigate the myocardial and brain function protection and hemodynamic stability effects of the bundle of care which formed by selective α2 -adrenergic receptor agonist alpha -methylnorepinephrine (α-MNE), κ-opioid receptor agonist U50488H, remifentani and transient receptor potential vanilloid type 1 ( TRPV1 ) agonist dihydrocapsaicin ( DHC ) drug -induced mild hypothermia at early stage of post -cardiac arrest syndrome ( PCAS) in rabbits.Methods Fifty rabbits were randomly divided into 5 groups , A group: operation control group , only anesthesia and tubes inserted without performing ventricular fibrillation ( VF ); B group: epinephrine group , injecting epinephrine(30 μg/kg) during CPR;C group:injectingα-MNE(100 μg/kg) and U50488H (1.5 mg/kg ) during CPR; D group: the similar to C group during cardiopulmonary resuscitation (CPR), but when achieved return of spontaneous circulation (ROSC), surface cooling(ice, 100 g/100 mg) was given to quickly cool rabbit to 32℃~35℃(anal temperature) lasting to the end.Meanwhile, large dose of remifentani [6.0 μg/(kg· min)] was continuously pumped intravenously; E group: the similar to C group during CPR too, but after ROSC, DHC [1.0 mg/(kg· h)] and remifentani [6.0μg/( kg· min) ] were continuously intravenous pumped in order to obtain drug -induced mild hypothermia . Blood samples were collected at before VF , 30, 60, 120, 240, 360 min after CPR, and the levels of troponin I ( cTnI) and neuron -specific enolase ( NSE) were measured, in addition, hemodynamic parameters were also recorded at above time points .Statistical analysis was performed by using SPSS software.Results ①After CPR, compared with group A, MAP, peak -dp/dt, peak +dp/dt at the time points were significantly lower(P<0.05), and LVEDP was significantly increased(P<0.05)in other four groups , but there were no differences between D and E groups ( P>0.05 ) .MAP in D and E groups were significantly higher than that in B group (P<0.05) after the 60 minute point, peak-dp/dt, peak+dp/dt and LVEDP had significant difference (P<0.05) after the 30 minute point too.MAP, peak-dp/dt, peak+dp/dt and LVEDP in D and E groups also had significant difference with C group (P<0.05) after the 60 minute point.②cTnI and NSE in A group were significantly lower than that in the other groups(P<0.05).Moreover, there were no statistical differences in D and E groups (P>0.05 ) , but they were higher than B group ( after CPR ) and C group ( after the 60 minute point ) ( P<0.05).③Rabbit treated with surface cooling and DHC decreased from 38.2 ℃ to 33.9 ℃ ( t=0.5 hours) and 38.5℃to 34.3℃(t=0.5 hours), respectively in D group and E group, and did not show significance difference (P>0.05).Conclusion Bundle of care α-MNE, U50488H, remifentani and DHC drug-induced mild hypothermia cures the early stage of PCAS can effectively reduce myocardial and brain injury and optimize post CPR hemodynamic .And DHC intravenously drip can quickly and effectively induce mild hypothermia .