title: Relationship between timing of cooling and outcomes in adult comatose cardiac arrest patients treated with targeted temperature management.
abstract: Studies examining associations between time to target temperature and outcomes in cardiac arrest patients who underwent targeted temperature management (TTM) have shown inconsistent results. We examined these associations separately for time from restoration of spontaneous circulation to TTM initiation (pre-induction time) and time from TTM initiation to target temperature (induction time). Furthermore, we examined whether critical time thresholds exist if there is an association.
  
  
  
  This was a single-centre retrospective observational study including adult cardiac arrest patients treated with TTM from 2008 to 2015. We tested the associations of pre-induction time and induction time with outcomes at hospital discharge using multivariate logistic regression analysis. We then performed additional multivariate analyses, each with the significant timing variable at different binary cutoffs.
  
  
  
  A total of 515 patients were analysed. At hospital discharge, 357 patients (69.3%) were alive, of whom 161 (31.3%) had a favourable neurologic outcome. In multivariate analysis, a shorter pre-induction time was independently associated with a favourable neurologic outcome (odds ratio [OR], 1.110; 95% confidence interval [CI], 1.025-1.202), whereas the induction time was not (OR, 0.954; 95% CI, 0.852-1.067). We found two pre-induction time thresholds (120 and 360min) that were associated with neurologic outcome.
  
  
  
  We found that a shorter pre-induction time was independently associated with a favorable neurologic outcome at hospital discharge, whereas induction time was not. We also found two time thresholds at 120 and 360min, after which initiation of cooling was associated with a worse neurologic outcome.
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, Republic of Korea. Electronic address: bbukkuk@hanmail.net.
authors.forename: Byung Kook
authors.initials: BK
authors.lastname: Lee
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, Republic of Korea. Electronic address: neoneti@hanmail.net.
authors.forename: Kyung Woon
authors.initials: KW
authors.lastname: Jeung
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, Republic of Korea. Electronic address: xnxn77@hanmail.net.
authors.forename: Yong Hun
authors.initials: YH
authors.lastname: Jung
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, Republic of Korea. Electronic address: ggodhkekf@hanmail.net.
authors.forename: Dong Hun
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, Republic of Korea. Electronic address: magicwizard2@hanmail.net.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, Republic of Korea. Electronic address: semi-moon@hanmail.net.
authors.forename: Yong Soo
authors.initials: YS
authors.lastname: Cho
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, Republic of Korea. Electronic address: docheo@hanmail.net.
authors.forename: Tag
authors.initials: T
authors.lastname: Heo
authors.affiliation: Department of Emergency Medical Services, Honam University, 417 Eodeung-daero, Gwangsangu, Gwangju, Republic of Korea. Electronic address: emt-jonggun@hanmail.net.
authors.forename: Jong Geun
authors.initials: JG
authors.lastname: Yun
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 42 Jebong-ro, Donggu, Gwangju, Republic of Korea. Electronic address: minyi46@hanmail.net.
authors.forename: Yong Il
authors.initials: YI
authors.lastname: Min
mesh_terms: D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000009:adverse effects / Q000379:methods / Q000706:statistics & numerical data; D003128:Coma / Q000150:complications / Q000209:etiology / Q000628:therapy; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods / Q000592:standards; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy; D010043:Outcome and Process Assessment, Health Care; D010351:Patient Discharge / Q000706:statistics & numerical data; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D013997:Time Factors; D061665:Time-to-Treatment
keywords: Body temperature regulation; Heart arrest; Induced hypothermia; Prognosis