Liquid ventilation with perfluorocarbons facilitates resumption of spontaneous circulation in a swine cardiac arrest model.
BACKGROUND
Induced external hypothermia during ventricular fibrillation (VF) improves resuscitation outcomes. Our objectives were twofold (1) to determine if very rapid hypothermia could be achieved by intrapulmonary administration of cold perfluorocarbons (PFC), thereby using the lungs as a vehicle for targeted cardiopulmonary hypothermia, and (2) to determine if this improved resuscitation success.


METHODS
Part 1: Nine female swine underwent static intrapulmonary instillation of cold perfluorocarbons (PFC) during electrically induced VF. Part 2: Thirty-three female swine in VF were immediately ventilated via total liquid ventilation (TLV) with pre-oxygenated cold PFC (-15 degrees C) or warm PFC (33 degrees C), while control swine received no ventilation during VF. All swine in both Parts 1 and 2 underwent VF arrest for 11 min, then defibrillation, ventilation and closed chest massage until resumption of spontaneous circulation (ROSC). The endpoint was continued spontaneous circulation for 1h without pharmacologic support.


RESULTS
Static intrapulmonary instillation of cold PFC achieved rapid cardiopulmonary hypothermia; pulmonary artery (PA) temperature of 33.5+/-0.2 degrees C was achieved by 10 min. Nine of 9 achieved ROSC. Hypothermia was achieved faster using TLV: at 6 min VF, cold TLV temperature was 32.9+/-0.4 degrees C vs. cold static instillation temperature 34.3+/-0.2 degrees C. Nine of 11 cold TLV swine achieved ROSC for 1h vs. 3 of 11 control swine (p=0.03). Warm PFC also appeared to be beneficial, with a trend toward greater achievement of ROSC than control (ROSC; warm PFC 8 of 11 vs. control 3 of 11, p=0.09).


CONCLUSIONS
Targeted cardiopulmonary intra-arrest moderate hypothermia was achieved rapidly by static intrapulmonary administration of cold PFC and more rapidly by total liquid ventilation with cold PFC; resumption of spontaneous circulation was facilitated. Warm PFC showed a trend toward facilitating ROSC.
Staffey
Kimberly S
KS
Department of Internal Medicine, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA. Kimberly-staffey@uiowa.edu
Dendi
Raghuveer
R
Brooks
Leonard A
LA
Pretorius
Andrew M
AM
Ackermann
Laynez W
LW
Zamba
K D
KD
Dickson
Eric
E
Kerber
Richard E
RE
D000818:Animals; D004195:Disease Models, Animal; D005240:Feasibility Studies; D005260:Female; D005466:Fluorocarbons / Q000008:administration & dosage*; D006323:Heart Arrest / Q000628:therapy*; D007036:Hypothermia, Induced / Q000379:methods*; D016014:Linear Models; D021061:Liquid Ventilation / Q000379:methods*; D009010:Monte Carlo Method; D018709:Statistics, Nonparametric; D013552:Swine
D005466:Fluorocarbons