title: Initial end-tidal CO2partial pressure predicts outcomes of in-hospital cardiac arrest.
abstract: BACKGROUND
  Monitoring the partial pressure of end-tidal carbon dioxide (PEtco2) has been advocated since 2010 as an index of resuscitation efforts. However, related research has largely focused on out-of-hospital cardiac arrest victims. In-hospital cardiac arrest (IHCA) differs in terms of etiologies and demographics, the merit of initial PEtco2values was explored.
  
  
  METHODS
  This was a retrospective study in a single medical center between February 2011 and August 2014. Eligible subjects had suffered nontraumatic IHCA in the emergency department, where resuscitation was performed in accord with 2010 American Heart Association guidelines. Patients with initial PEtco2recordings via capnography were recruited.
  
  
  RESULTS
  A total of 353 IHCA events with initial PEtco2were recorded in 202 patients (male, 61.4%; mean age, 67.0 ± 16.2 years). Shockable rhythm (ventricular tachycardia/ventricular fibrillation) accounted for 11.8%. A cut point of 25.5 mm Hg was established for initial PEtco2, creating 2 tiers of sustained return of spontaneous circulation (ROSC) that differed significantly in cumulative survival probability (log rank test, P = .002). For patients with initial PEtco2<25.5 mm Hg, survival benefit ceased at an earlier point in resuscitation, whereas above this threshold, the probability of survival cumulatively increased for a longer period. In multivariate analysis, initial PEtco2>25.5 mm Hg was found independently predictive of sustained ROSC (odds ratio, 2.64; 95% confidence interval, 1.43-4.88; P = .002), and survival to discharge (odds ratio, 3.10; 95% confidence interval, 1.26-7.60; P = .014), but failed to correlate with neurologic outcome.
  
  
  CONCLUSIONS
  In IHCA, the therapeutic threshold for initial PEtco2should set fairly higher to encourage more pulmonary flow and increase the likelihood of sustained ROSC.
authors.affiliation: Department of Emergency Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Departments of Emergency Medicine, Taipei Medical University Hospital, Taipei, Taiwan; Departments of Emergency Medicine, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: anyimilk@gmail.com.
authors.forename: An-Yi
authors.initials: AY
authors.lastname: Wang
authors.affiliation: Departments of Emergency Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chien-Hua
authors.initials: CH
authors.lastname: Huang
authors.affiliation: Departments of Emergency Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Wei-Tien
authors.initials: WT
authors.lastname: Chang
authors.affiliation: Departments of Emergency Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Min-Shan
authors.initials: MS
authors.lastname: Tsai
authors.affiliation: Departments of Emergency Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Chih-Hung
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Departments of Emergency Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Emergency Medicine, Lotung Poh-Ai Hospital, Yilan County, Taiwan.
authors.forename: Wen-Jone
authors.initials: WJ
authors.lastname: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019296:Capnography; D002245:Carbon Dioxide / Q000032:analysis / Q000502:physiology*; D016887:Cardiopulmonary Resuscitation; D005260:Female; D006323:Heart Arrest / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D007297:Inpatients; D008297:Male; D008875:Middle Aged; D010313:Partial Pressure; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000150:complications; D013990:Tidal Volume; D014693:Ventricular Fibrillation / Q000150:complications
chemical_list: D002245:Carbon Dioxide