title: Association between mean arterial blood gas tension and outcome in cardiac arrest patients treated with therapeutic hypothermia.
abstract: BACKGROUND
  Studies investigating the relationship between blood gas tension and outcome in cardiac arrest survivors have reported conflicting results. This might have resulted from the use of a blood gas value at a single time point and the difference in the proportion of patients treated with therapeutic hypothermia (TH). We investigated the association of the mean blood gas tensions calculated from blood gas values obtained between restoration of spontaneous circulation and end of TH with the outcome in cardiac arrest patients treated with TH.
  
  
  METHODS
  This was a retrospective observational study including 213 adult cardiac arrest patients. The cohort was divided into four categories based on the distribution of the mean Pao2 data using quartiles as cut-off values between categories. According to the mean Paco2, the cohort was divided into hypocarbia, normocarbia, and hypercarbia. The primary outcome was in-hospital mortality.
  
  
  RESULTS
  In multivariate analysis, the mean Pao2 quartile was not associated with in-hospital mortality, but hypocarbia was significantly associated with increased risk of in-hospital mortality (odds ratio 2.522; 95% confidence interval 1.184-5.372; P = .016). We found a V-shaped independent association between the mean Pao2 and poor neurologic outcome at hospital discharge, with the risk of poor neurologic outcome increasing with a descending and ascending Pao2 ranges.
  
  
  CONCLUSIONS
  Mean Pao2 had no independent association with in-hospital mortality whereas hypocarbia was independently associated with in-hospital mortality. We also found a V-shaped independent association between the mean Pao2 and poor neurologic outcome at hospital discharge.
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 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, 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, KS Hospital, Gwangju, Republic of Korea. Electronic address: apostlelee@hanmail.net.
authors.forename: Hyoung Youn
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Department of Emergency Medicine, Myongji Hospital, Gyeonggi-do, Republic of Korea. Electronic address: dorinim@gmail.com.
authors.forename: Seung Joon
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 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, Gwangju, Republic of Korea. Electronic address: wanggi@hanmail.net.
authors.forename: Wang Ki
authors.initials: WK
authors.lastname: Lee
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, Gwangju, Republic of Korea. Electronic address: docheo@hanmail.net.
authors.forename: Tag
authors.initials: T
authors.lastname: Heo
authors.affiliation: Department of Emergency Medicine, Chonnam National University Hospital, 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; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006323:Heart Arrest / Q000097:blood / Q000401:mortality / Q000628:therapy*; D017052:Hospital Mortality; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen