End Tidal CO2 Is a Quantitative Measure of Cardiac Arrest


Address for reprints: Ruchir Sehra, M.D., F.A.C.C, Loma Linda University Medical Center, 11234 Anderson Street, Rm 4433, Loma Linda, CA 92354. Fax: 909 558-0311; e-mail: ruchir@earthlink.net


SEHRA, R., et al.: End Tidal CO2 Is a Quantitative Measure of Cardiac Arrest.Purpose of the study: Predictors of severity of cardiac arrest or efficacy of cardiopulmonary resuscitation are few. Respiratory end tidal CO2 (ETCO) is a marker of pulmonary blood flow and, possibly, cardiac arrest. The purpose of this study was to evaluate ETCO as a quantitative marker of cardiac arrest in a human model of ventricular fibrillation (VF). Methods: Thirty-one cardiac arrest/VF episodes (mean BP < 40 mmHg) in 8 men and 3 women mean age = 42 ± 24 years, mean left ventricular ejection fraction = 39%) undergoing defibrillator (ICD) implant for ventricular tachycardia or previous cardiac arrest were evaluated with continuous ETCO monitoring during defibrillation threshold testing. All patients but one were intubated. Results: Significant differences(P < 0.001)were noted between ETCO values prior (mean 37.2 ± 6.8 mmHg) versus during VF (mean 27.1 ± 5.9 mmHg), and during VF versus return of spontaneous circulation (mean 36.6 ± 6.6 mmHg). ETCO decreased by 23%± 8% from pre-VF to during VF. It increased by 37%± 16% during VF to return of spontaneous circulation. These changes were significantly different(P < 0.001). Conclusion: Significant changes in ETCO were measured during VF arrest. ETCO can predict acute cardiac arrest in a quantitative manner. (PACE 2003; 26[Pt. II]:515–517)