title: Prevalence and factors correlating with hyperoxia exposure following cardiac arrest--an observational single centre study.
abstract: OBJECTIVE
  Arterial hyperoxia during care in the intensive care unit (ICU) has been found to correlate with mortality after cardiac arrest (CA). We examined the prevalence of hyperoxia following CA including pre-ICU values and studied differences between those exposed and those not exposed to define predictors of exposure.
  
  
  METHODS
  A retrospective analysis of a prospectively collected cohort of cardiac arrest patients treated in an Australian tertiary hospital between August 2008 and July 2010. Arterial blood oxygen values and used fractions of oxygen were recorded during the first 24 hours after the arrest. Hyperoxia was defined as any arterial oxygen value greater than 300 mmHg. Chi-square test was used to compare categorical data and Mann-Whitney U-test to continuous data. Statistical methods were used to identify predictors of hyperoxia exposure.
  
  
  RESULTS
  Of 122 patients treated in the ICU following cardiac arrest 119 had one or several arterial blood gases taken and were included in the study. Of these, 49 (41.2%) were exposed to hyperoxia and 70 (58.8%) were not during the first 24 hours after the CA. Those exposed had longer delays to return of spontaneous circulation (26 minutes vs. 10 minutes) and a longer interval to ICU admission after the arrest (4 hours compared to 1 hour). Location of the arrest was an independent predictor of exposure to hyperoxia (P-value = 0,008) with out-of-hospital cardiac arrest patients being more likely to have been exposed (65%), than those with an in-hospital (21%) or ICU (30%) cardiac arrest. Out-of-hospital cardiac arrest patients had higher oxygen concentrations to the fraction of inspired oxygen ratios.
  
  
  CONCLUSIONS
  Hyperoxia exposure was more common than previously reported and occurred more frequently in association with out-of-hospital cardiac arrest, longer times to ROSC and delays to ICU admission.
authors: Annika
authors: A
authors: Nelskylä
authors: Michael J
authors: MJ
authors: Parr
authors: Markus B
authors: MB
authors: Skrifvars
mesh_terms: D000368:Aged; D001784:Blood Gas Analysis; D016887:Cardiopulmonary Resuscitation / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000150:complications / Q000628:therapy*; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D018496:Hyperoxia / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009517:New South Wales / Q000453:epidemiology; D010100:Oxygen / Q000097:blood; D015995:Prevalence; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome
chemical_list: D010100:Oxygen
references: Resuscitation. 2012 Aug;83(8):982-5
references: 22322284
references: N Engl J Med. 2002 Feb 21;346(8):557-63
references: 11856794
references: Anesthesiology. 2010 Feb;112(2):288-97
references: 20098129
references: Resuscitation. 2012 Oct;83(10):1201-5
references: 22699210
references: Circulation. 2010 Nov 2;122(18 Suppl 3):S768-86
references: 20956225
references: Resuscitation. 2012 Dec;83(12):1456-61
references: 22841610
references: JAMA. 2010 Jun 2;303(21):2165-71
references: 20516417
references: Angiogenesis. 2007;10(2):133-40
references: 17332988
references: J Cereb Blood Flow Metab. 1997 Apr;17(4):430-6
references: 9143225
references: J Thorac Cardiovasc Surg. 2003 Dec;126(6):1730-5
references: 14688680
references: Arch Intern Med. 2001 Sep 10;161(16):2007-12
references: 11525703
references: J Thorac Cardiovasc Surg. 2001 Oct;122(4):753-8
references: 11581609
references: N Engl J Med. 2004 Aug 12;351(7):647-56
references: 15306666
references: Resuscitation. 2004 Nov;63(2):189-94
references: 15531071
references: Resuscitation. 2012 Jun;83(6):728-33
references: 22281225
references: J Perinatol. 2006 Nov;26(11):700-5
references: 17036032
references: Resuscitation. 2003 Sep;58(3):297-308
references: 12969608
references: Crit Care. 2011;15(2):R90
references: 21385416
references: Resuscitation. 2005 Sep;66(3):271-83
references: 16129543
references: Crit Care Med. 2012 Dec;40(12):3135-9
references: 22971589
references: Resuscitation. 2008 Dec;79(3):350-79
references: 18963350