Hemodynamic rescue and ECG stability during chest compressions using adenosine and lidocaine after 8-minute asphyxial hypoxia in the rat.
BACKGROUND
Sudden cardiac death generally arises from either ventricular fibrillation or asphyxial hypoxia. In an effort to translate the cardioprotective effects of adenosine and lidocaine (AL) from hemorrhagic shock to cardiopulmonary resuscitation, we examined the effect of AL on hemodynamics and electrocardiogram (ECG) stability in the rat model of asphyxial hypoxia.


METHODS
Male Sprague-Dawley rats were randomly assigned to 1 of 4 groups (n = 8): saline (SAL), adenosine (ADO), lidocaine (LIDO), and AL. Cardiac arrest (mean arterial pressure <10 mm Hg) was induced by clamping the ventilator line for 8 minutes. A 0.5-mL intravenous drug bolus was injected followed by chest compressions (300 min(-1)), which were repeated every 5 minutes for 1 hour.


RESULTS
Return of spontaneous circulation was achieved in 5 SAL (62.6%), 4 ADO (50%), 7 LIDO (87.5%), and 8 AL rats (100%) within 5 minutes but could not be sustained. During chest compressions, mean arterial pressure was consistently higher in the AL-treated rats compared with all groups (P < .05; 35-45 and 55 minutes) followed by the LIDO group and was lowest in the ADO and SAL groups (P < .05). Systolic pressure followed a similar pattern. In addition, diastolic pressure in the AL-treated rats was significantly higher from 25 to 60 minutes than LIDO and ADO alone or SAL, and heart rate was 30% to 40% lower. Improved ECG rhythm and R-R variability were apparent in AL-treated rats during early compressions and hands-off intervals.


CONCLUSIONS
We conclude that a small bolus of 0.9% NaCl AL improved hemodynamics with possible diastolic rescue and ECG stabilization during chest compressions compared with ADO, LIDO, or SAL controls.
Department of Physiology and Pharmacology, Heart and Trauma Research Laboratory, James Cook University, Queensland 4811, Australia.
Yulia
Y
Djabir
Geoffrey P
GP
Dobson
D000241:Adenosine / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D001237:Asphyxia / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D016887:Cardiopulmonary Resuscitation / Q000379:methods; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D004562:Electrocardiography; D006321:Heart / Q000503:physiopathology; D006323:Heart Arrest / Q000188:drug therapy / Q000628:therapy; D006336:Heart Massage / Q000379:methods; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D008012:Lidocaine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000008:administration & dosage / Q000627:therapeutic use; D013997:Time Factors
D002316:Cardiotonic Agents; D012965:Sodium Chloride; D008012:Lidocaine; D000241:Adenosine