Perfluorocarbon induced intra-arrest hypothermia does not improve survival in a swine model of asphyxial cardiac arrest.
BACKGROUND
Pulseless electrical activity is an important cause of cardiac arrest. Our purpose was to determine if induction of hypothermia with a cold perfluorocarbon-based total liquid ventilation (TLV) system would improve resuscitation success in a swine model of asphyxial cardiac arrest/PEA.


METHODS
Twenty swine were randomly assigned to control (C, no ventilation, n=11) or TLV with pre-cooled PFC (n=9) groups. Asphyxia was induced by insertion of a stopper into the endotracheal tube, and continued in both groups until loss of aortic pulsations (LOAP) was reached, defined as a pulse pressure less than 2mmHg. The TLV animals underwent asphyxial arrest for an additional 2min after LOAP, followed by 3min of hypothermia, prior to starting CPR. The C animals underwent 5min of asphyxia beyond LOAP. Both groups then underwent CPR for at least 10min. The endpoint was the resumption of spontaneous circulation maintained for 10min.


RESULTS
Seven of 9 animals achieved resumption of spontaneous circulation (ROSC) in the TLV group vs. 5 of 11 in the C group (p=0.2). The mean pulmonary arterial temperature was lower in total liquid ventilation animals starting 4min after induction of hypothermia (TLV 36.3+/-0.2 degrees C vs. C 38.1+/-0.2 degrees C, p<0.0001). Arterial P(O)(2) was higher in total liquid ventilation animals at 2.5min of CPR (TLV 76+/-12mmHg vs. C 44+/-2mmHg; p=0.03).


CONCLUSIONS
Induction of moderate hypothermia using perfluorocarbon-based total liquid ventilation did not improve ROSC success in this model of asphyxial cardiac arrest.
Albaghdadi
Ali S
AS
The Cardiovascular Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, United States.
Brooks
Leonard A
LA
Pretorius
Andrew M
AM
Kerber
Richard E
RE
D000818:Animals; D001237:Asphyxia / Q000150:complications*; D001769:Blood; D001831:Body Temperature; D016887:Cardiopulmonary Resuscitation; D003326:Coronary Circulation; D005260:Female; D005466:Fluorocarbons / Q000627:therapeutic use*; D006323:Heart Arrest / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D007036:Hypothermia, Induced; D021061:Liquid Ventilation; D008297:Male; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011651:Pulmonary Artery / Q000503:physiopathology; D020127:Recovery of Function
D005466:Fluorocarbons; D010100:Oxygen