An experimental algorithm versus standard advanced cardiac life support in a swine model of out-of-hospital cardiac arrest.
OBJECTIVE
To compare an experimental algorithm with standard advanced cardiac life support in a swine model of out-of-hospital cardiac arrest.


METHODS
Randomized, controlled experimental trial. SETTING/TYPE OF PARTICIPANT: Animal laboratory using swine.


METHODS
Eighteen swine (17.8 to 23.7 kg) were sedated, intubated, anesthetized, and instrumented for monitoring of arterial and central venous pressures and ECG. Ventricular fibrillation was induced using a bipolar pacing catheter. Animals were randomized to treatment with the experimental algorithm or standard advanced cardiac life support therapy after eight minutes of untreated ventricular fibrillation. The experimental algorithm consisted of starting CPR; giving high-dose epinephrine (0.20 mg/kg), lidocaine (1.0 mg/kg), bretylium (5.0 mg/kg), and propranolol (0.5 to 1.0 mg) by peripheral IV; hyperventilating (20 to 25 breaths per minute); and delaying countershock (5 J/kg) 60 seconds after completion of drug delivery. Data were analyzed with the Student's t-test and Fisher's exact test.


RESULTS
Outcome variables were arterial and central venous pressures, return of spontaneous circulation, and one-hour survival. Hemodynamics were not different between groups during CPR. Return of spontaneous circulation occurred in seven of nine swine (77%) in the experimental algorithm group versus two of nine swine (22%) in the advanced cardiac life support group (P = .057). Four of nine swine (44%) in the experimental algorithm group survived to one hour versus none of the animals in the advanced cardiac life support group (P = .041).


CONCLUSIONS
In this swine model of out-of-hospital cardiac arrest, animals treated with an experimental algorithm had a significant improvement in one-hour survival compared with those treated with advanced cardiac life support.
Menegazzi
J J
JJ
Center for Emergency Medicine of Western Pennsylvania.
Davis
E A
EA
Yealy
D M
DM
Molner
R L
RL
Nicklas
K A
KA
Hosack
G M
GM
Honingford
E A
EA
Klain
M M
MM
D000465:Algorithms; D000818:Animals; D001949:Bretylium Compounds / Q000627:therapeutic use; D016887:Cardiopulmonary Resuscitation; D004554:Electric Countershock; D004632:Emergency Medical Services / Q000379:methods; D004837:Epinephrine / Q000627:therapeutic use; D006323:Heart Arrest / Q000188:drug therapy / Q000401:mortality / Q000628:therapy*; D008012:Lidocaine / Q000627:therapeutic use; D008020:Life Support Care; D008955:Models, Cardiovascular; D011897:Random Allocation; D012151:Resuscitation / Q000379:methods*; D015996:Survival Rate; D013552:Swine
D001949:Bretylium Compounds; D008012:Lidocaine; C045166:bretylium; D004837:Epinephrine