Background: During cardiopulmonary resuscitation (CPR), end-tidal carbon dioxide (EtCO2) is primarily determined by pulmonary blood flow, thereby reflecting the blood flow generated by CPR. We aimed to develop an EtCO2 trajectory-based prediction model for prognostication at specific time points during CPR in patients with out-of-hospital cardiac arrest (OHCA).
\nMethods: We screened patients receiving CPR between 2015–2021 from a prospectively collected database of a tertiary-care medical center. The primary outcome was survival to hospital discharge. We used group-based trajectory modeling to identify the EtCO2 trajectories. Multivariable logistic regression analysis was used for model development and internally validated using bootstrapping. We assessed performance of the model using the area under the receiver operating characteristic curve (AUC).
\nResults: The primary analysis included 542 patients with a median age of 68.0 years. Three distinct EtCO2 trajectories were identified in patients resuscitated for 20 minutes (min): low (average EtCO2 10.0 millimeters of mercury [mm Hg]; intermediate (average EtCO2 26.5 mm Hg); and high (average EtCO2: 51.5 mm Hg). Twenty-min EtCO2 trajectory was fitted as an ordinal variable (low, intermediate, and high) and positively associated with survival (odds ratio 2.25, 95% confidence interval [CI] 1.07–4.74). When the 20-min EtCO2 trajectory was combined with other variables, including arrest location and arrest rhythms, the AUC of the 20-min prediction model for survival was 0.89 (95% CI 0.86–0.92). All predictors in the 20-min model remained statistically significant after bootstrapping.
\nConclusion: Time-specific EtCO2 trajectory was a significant predictor of OHCA outcomes, which could be combined with other baseline variables for intra-arrest prognostication. For this purpose, the 20-min survival model achieved excellent discriminative performance in predicting survival to hospital discharge.
","language":null,"license":{"name":"Creative Commons Attribution 4.0","short_name":"CC BY 4.0","text":"Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.\r\n\r\nNo additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.","url":"https://creativecommons.org/licenses/by/4.0"},"keywords":[{"word":"cardiopulmonary resuscitation"},{"word":"End-tidal Carbon Dioxide"},{"word":"Group-based trajectory modelling"},{"word":"Out-of-hospital Cardiac Arrest"},{"word":"survival"},{"word":"trajectory"}],"section":"Critical Care","is_remote":true,"remote_url":"https://escholarship.org/uc/item/55m7h987","frozenauthors":[{"first_name":"Chih-Hung","middle_name":"","last_name":"Wang","name_suffix":"","institution":"National Taiwan University, College of Medicine, Department of Emergency Medicine, Taipei, Taiwan; National Taiwan University Hospital, Department of Emergency Medicine, Taipei, Taiwan","department":"None"},{"first_name":"Tsung-Chien","middle_name":"","last_name":"Lu","name_suffix":"","institution":"National Taiwan University, College of Medicine, Department of Emergency Medicine, Taipei, Taiwan; National Taiwan University Hospital, Department of Emergency Medicine, Taipei, Taiwan","department":"None"},{"first_name":"Joyce","middle_name":"","last_name":"Tay","name_suffix":"","institution":"National Taiwan University Hospital, Department of Emergency Medicine, Taipei, Taiwan","department":"None"},{"first_name":"Cheng-Yi","middle_name":"","last_name":"Wu","name_suffix":"","institution":"National Taiwan University Hospital, Department of Emergency Medicine, Taipei, Taiwan","department":"None"},{"first_name":"Meng-Che","middle_name":"","last_name":"Wu","name_suffix":"","institution":"National Taiwan University Hospital, Department of Emergency Medicine, Taipei, Taiwan","department":"None"},{"first_name":"Chun-Yen","middle_name":"","last_name":"Huang","name_suffix":"","institution":"Far Eastern Memorial Hospital, Department of Emergency Medicine, New Taipei City, Taiwan","department":"None"},{"first_name":"Chu-Lin","middle_name":"","last_name":"Tsai","name_suffix":"","institution":"National Taiwan University, College of Medicine, Department of Emergency Medicine, Taipei, Taiwan; National Taiwan University Hospital, Department of Emergency Medicine, Taipei, Taiwan","department":"None"},{"first_name":"Chien-Hua","middle_name":"","last_name":"Huang","name_suffix":"","institution":"National Taiwan University, College of Medicine, Department of Emergency Medicine, Taipei, Taiwan; National Taiwan University Hospital, Department of Emergency Medicine, Taipei, Taiwan","department":"None"},{"first_name":"Matthew","middle_name":"Huei-Ming","last_name":"Ma","name_suffix":"","institution":"National Taiwan University, College of Medicine, Department of Emergency Medicine, Taipei, Taiwan; National Taiwan University Hospital, Department of Emergency Medicine, Taipei, Taiwan; National Taiwan University Hospital Yunlin Branch, Department of Emergency Medicine, Yunlin County, Taiwan","department":"None"},{"first_name":"Wen-Jone","middle_name":"","last_name":"Chen","name_suffix":"","institution":"National Taiwan University, College of Medicine, Department of Emergency Medicine, Taipei, Taiwan; National Taiwan University Hospital, Department of Emergency Medicine, Taipei, Taiwan","department":"None"}],"date_submitted":"2023-07-18T20:03:43Z","date_accepted":"2023-07-18T20:03:43Z","date_published":"2024-06-11T13:00:00Z","render_galley":{"label":"Final Article","type":"pdf","path":"https://journalpub.escholarship.org/westjem/article/18403/galley/14438/download/"},"galleys":[{"label":"Layout","type":"pdf","path":"https://journalpub.escholarship.org/westjem/article/18403/galley/10105/download/"},{"label":"Final Article","type":"pdf","path":"https://journalpub.escholarship.org/westjem/article/18403/galley/14438/download/"}]}