Effects of epinephrine and vasopressin on median fibrillation frequency and defibrillation success in a porcine model of cardiopulmonary resuscitation.
OBJECTIVE
This study was designed to assess whether median frequency of ventricular fibrillation (VF) correlates with myocardial blood flow and defibrillation success during cardiopulmonary resuscitation (CPR) after epinephrine or vasopressin administration.


RESULTS
After 4 min of VF and 3 min of CPR, 14 pigs received 0.045 mg/kg epinephrine or 0.4 U/kg vasopressin. Using radio-labeled microspheres, median myocardial blood flow during CPR before, and 90 s and 5 min after drug administration (DA) was 15.5 (12.6, 23.1; 25th percentile, 75th percentile), 26.4 (18.5, 29.1), 16.9 (14.9, 19.1) mL min-1 100 g-1, respectively, in the epinephrine, and 16.9 (15.4, 18.9), 48.1 (36.9, 68.9) (P < 0.05 vs. before DA), 52.3 (38.5, 65.0) mL min-1 100 g-1, respectively, in the vasopressin group. Using spectral analysis of VF, median frequency of VF was 11.0 (10.7, 11.8), 11.3 (9.6, 13.1), 10.2, (8.8, 11.4) Hz, respectively, in the epinephrine, and 10.1 (10.0, 10.5), 11.7 (11.1, 14.2) (P < 0.05 vs. before DA), 13.2 (11.5, 13.9) Hz, respectively, in the vasopressin group at the same points in time. Median frequency correlates significantly with myocardial blood flow in the epinephrine (n = 21); rs = 0.772; P < 0.001) and in the vasopressin group (n = 21; rs = 0.905; P < 0.001). Median fibrillation frequency before the first defibrillation was 13.0 (12.2, 13.2) Hz in resuscitated (n = 8) and 9.2 (8.3, 10.2) Hz (n = 6) in non-resuscitated animals (P < 0.01).


CONCLUSIONS
We conclude that median frequency of VF reflects myocardial blood flow and the chance of successful defibrillation during closed-chest CPR after vasopressor treatment in a porcine model of VF.
Strohmenger
H U
HU
Department of Anesthesiology and Critical Care Medicine, University of Ulm, Germany.
Lindner
K H
KH
Prengel
A W
AW
Pfenninger
E G
EG
Bothner
U
U
Lurie
K G
KG
D000322:Adrenergic Agonists / Q000008:administration & dosage / Q000627:therapeutic use*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D016887:Cardiopulmonary Resuscitation; D003326:Coronary Circulation / Q000187:drug effects; D004195:Disease Models, Animal; D004562:Electrocardiography; D004837:Epinephrine / Q000008:administration & dosage / Q000627:therapeutic use*; D006323:Heart Arrest / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy; D008863:Microspheres; D010100:Oxygen / Q000097:blood; D011188:Potassium / Q000097:blood; D012815:Signal Processing, Computer-Assisted; D012964:Sodium / Q000097:blood; D013552:Swine; D014662:Vasoconstrictor Agents / Q000627:therapeutic use*; D014667:Vasopressins / Q000627:therapeutic use*; D014693:Ventricular Fibrillation / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*
D000322:Adrenergic Agonists; D014662:Vasoconstrictor Agents; D014667:Vasopressins; D002245:Carbon Dioxide; D012964:Sodium; D011188:Potassium; D010100:Oxygen; D004837:Epinephrine