title: End tidal CO2 is a quantitative measure of cardiac arrest.
abstract: OBJECTIVE
  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).
  
  
  CONCLUSIONS
  Significant changes in ETCO were measured during VF arrest. ETCO can predict acute cardiac arrest in a quantitative manner.
authors.affiliation: Loma Linda University Medical Center, 11234 Anderson Street, Rm 4433, Loma Linda, CA 92354, USA. ruchir@earthlink.net
authors.forename: Ruchir
authors.initials: R
authors.lastname: Sehra
authors.forename: Karen
authors.initials: K
authors.lastname: Underwood
authors.forename: Paul
authors.initials: P
authors.lastname: Checchia
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D002245:Carbon Dioxide / Q000032:analysis*; D016887:Cardiopulmonary Resuscitation; D017147:Defibrillators, Implantable; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006323:Heart Arrest / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008297:Male; D013318:Stroke Volume; D013990:Tidal Volume; D014693:Ventricular Fibrillation / Q000150:complications* / Q000628:therapy
chemical_list: D015415:Biomarkers; D002245:Carbon Dioxide