Effects of endothelin-1 on resuscitation rate during cardiac arrest.
OBJECTIVE
Endothelin-1 (ET-1) is a potent peripheral and coronary artery vasoconstrictor and has been shown to improve coronary perfusion pressure (CPP) during cardiac arrest. The effect of ET-1 on return of spontaneous circulation (ROSC) following cardiac arrest has not been studied. Our hypothesis was that ET-1 does not improve ROSC from cardiac arrest when compared to placebo.


METHODS
A total of 11 immature swine were used in this laboratory study. Animals were randomized to receive 300 microg ET-1 and standard dose epinephrine (SDE) or placebo and SDE during arrest. After a 10-min period of no-flow ventricular fibrillation (VF), CPR was performed for 3 min followed by ET-1/SDE or placebo/SDE administration. Following drug administration, standard ACLS was followed with SDE given every 3 min. Aortic pressure was monitored during resuscitation. ROSC was defined as any perfusing rhythm with a systolic pressure greater than 60 mmHg for 60 s. Animals received post-ROSC care as needed for 2 h post-ROSC. CPP and ROSC were analyzed using repeated measures ANOVA and Fischer's exact test respectively. P<0.05 was considered significant.


RESULTS
Pre-arrest variables and CPP prior to ET-1 administration were not different between groups. Following ET-1 administration, CPP was significantly increased at all time points in ET-1/SDE versus placebo/SDE animals. ROSC was achieved in 1/5 (20%) ET-1/SDE versus 1/6 (16.7%) placebo/SDE animals (P>0.05). The resuscitated ET-1/SDE animal survived 6.5 min compared to 120 min for the resuscitated placebo/SDE animal.


CONCLUSIONS
In our study, ET-1 administration during cardiac arrest increases CPP but does not improve ROSC.
DeBehnke
D J
DJ
Department of Emergency Medicine, FMLH-East, 9200 W. Wisconsin Ave, Milwaukee, WI 53226, USA. ddebehnk@mcw.edu
Benson
L
L
D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D003326:Coronary Circulation / Q000187:drug effects; D019332:Endothelin-1 / Q000627:therapeutic use*; D004837:Epinephrine / Q000627:therapeutic use; D006323:Heart Arrest / Q000188:drug therapy*; D015425:Myocardial Reperfusion; D011897:Random Allocation; D013552:Swine; D014662:Vasoconstrictor Agents / Q000627:therapeutic use*
D019332:Endothelin-1; D014662:Vasoconstrictor Agents; D004837:Epinephrine