title: Prognostication of out-of-hospital cardiac arrest patients by 3-min end-tidal capnometry level in emergency department.
abstract: OBJECTIVE
  To evaluate the role of initial ETCO2 value in prognostication of OHCA patients in an Asian-Chinese cohort.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Emergency departments of two regional hospitals in a cluster of Hong Kong.
  
  
  METHODS
  Patients were recruited prospectively from the local cardiac arrest registry from July 2012 to June 2013. Patients of non traumatic OHCA aged ≥18 years old were included. Patients of OHCA presented with postmortem changes, those who decided for Do Not Resuscitate (DNR), regained pulse before arrival, or those without proper documentation of ETCO2 would be excluded.
  
  
  RESULTS
  Primary outcome was return of spontaneous circulation (ROSC).
  
  
  RESULTS
  A 3-min ETCO2 >10mmHg was a predictor of ROSC with OR 18.16 (95% CI 4.79-51.32, p<0.001). The diagnostic accuracy of 3-min ETCO2 >10mmHg to predict ROSC: sensitivity was 0.95 (95% CI 0.89-0.98) while the specificity was 0.27 (95% CI 0.21-0.33). Positive predictive value was 0.40 (95% CI 0.34-0.46) while negative predictive value (NPV) was 0.92 (95% CI 0.82-0.97). Area under ROC curve of 3-min ETCO2 predicting ROSC was 0.80 (95% CI 0.71-0.91).
  
  
  CONCLUSIONS
  A 3-min ETCO2 ≤10mmHg was associated with poor prognosis and low chance of ROSC. Low ETCO2 level may have a role to reduce prolonged medically futile resuscitation.
authors.affiliation: Pok Oi Hospital, Hong Kong.
authors.forename: Kin Ming
authors.initials: KM
authors.lastname: Poon
authors.affiliation: Tuen Mun Hospital, Hong Kong. Electronic address: ectlui@yahoo.com.hk.
authors.forename: Chun Tat
authors.initials: CT
authors.lastname: Lui
authors.affiliation: Tuen Mun Hospital, Hong Kong.
authors.forename: Kwok Leung
authors.initials: KL
authors.lastname: Tsui
mesh_terms: D000368:Aged; D019296:Capnography / Q000379:methods*; D002245:Carbon Dioxide / Q000032:analysis*; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004636:Emergency Service, Hospital; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D058687:Out-of-Hospital Cardiac Arrest / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries; D013990:Tidal Volume / Q000502:physiology*; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide
keywords: Asystole; Casualty, Prognosis; End-tidal capnography; Resuscitation