Effect of arrest time on the hemodynamic efficacy of precordial compression.
OBJECTIVE
To evaluate the efficacy of conventional threshold levels of coronary perfusion pressure and end-tidal CO2 as predictors of resuscitability after prolonged cardiac arrest.


METHODS
Prospective, randomized, controlled animal study.


METHODS
University research laboratory.


METHODS
Twenty-one Sprague-Dawley rats, including three groups of seven animals in each group.


METHODS
Ventricular fibrillation was untreated for 9, 12, or 15 mins. After an additional 5-min interval of precordial compression, external direct current defibrillation was attempted.


RESULTS
All animals were successfully resuscitated after 9 mins of ventricular fibrillation but less than one half of the animals were successfully resuscitated after 15 mins of ventricular fibrillation. Each of seven animals survived for 24 hrs after 9 mins of untreated ventricular fibrillation but none of the animals survived after 15 mins of ventricular fibrillation. In this experimental setting, neither coronary perfusion pressure nor end-tidal CO2 produced by precordial compression was predictive of outcomes when the animals underwent progressively longer intervals of untreated cardiac arrest.


CONCLUSIONS
The efficacy of precordial compression--as measured by coronary perfusion pressure and end-tidal CO2 concentration after prolongation of untreated cardiac arrest--was not overtly compromised. However, the previously established critical threshold levels of coronary perfusion pressure and end-tidal CO2 failed as predictors of resuscitability after prolonged intervals of untreated cardiac arrest.
Duggal
C
C
Institute of Critical Care Medicine, University of Health Sciences/The Chicago Medical School, IL, USA.
Weil
M H
MH
Tang
W
W
Gazmuri
R J
RJ
Sun
S
S
D000818:Animals; D004195:Disease Models, Animal; D006323:Heart Arrest / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006439:Hemodynamics; D008297:Male; D011446:Prospective Studies; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012151:Resuscitation / Q000379:methods* / Q000706:statistics & numerical data; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000628:therapy