Early hyperoxemia is not associated with cardiac arrest outcome

• Published in: Resuscitation Vol. 140; pp. 185 - 193
• Main Authors: Humaloja, Jaana, Litonius, Erik, Efendijev, Ilmar, Folger, Daniel, Raj, Rahul, Pekkarinen, Pirkka T., Skrifvars, Markus B.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01-07-2019
• Subjects: arrest; Cardiac arrest; Cardiac arrest outcome; Hyperoxemia; Hyperoxia; In hospital cardiac arrest; Intensive care after cardiac arrest; Intensive care unit cardiac arrest; Neurological outcome; Out of hospital cardiac; Post cardiac arrest care; Post resuscitation care; Intensive care unit cardiac arrest; arrest; Hyperoxia; Cardiac arrest; Cardiac arrest outcome; Out of hospital cardiac; In hospital cardiac arrest; Neurological outcome; Post cardiac arrest care; Intensive care after cardiac arrest; Hyperoxemia; Post resuscitation care
• ISSN: 0300-9572; 1873-1570
• DOI: 10.1016/j.resuscitation.2019.04.035

Studies suggest that hyperoxemia increases short-term mortality after cardiopulmonary resuscitation (CPR), but the effect of hyperoxemia on long-term outcomes is unclear. We determined the prevalence of early hyperoxemia after CPR and its association with long-term neurological outcome and mortality.
We analysed data from adult cardiac arrest patients treated after CPR in tertiary ICUs during 2005–2013. We retrieved data from the resuscitation and the first arterial blood sample collected after return of spontaneous circulation (ROSC) (severe hyperoxemia defined as PaO2 > 40 kPa and moderate as PaO2 16–40 kPa). We inspected two outcomes, neurological performance at one year after resuscitation according to the Cerebral Performance Category and one-year mortality. We used logistic regression to test associations between hyperoxemia and the outcome and interaction analyses to test the effect of hyperoxemia exposure on the outcomes in smaller subgroups.
Of 1110 patients 11% had severe hyperoxemia, prevalence was 10% for out-of-hospital arrests, 13% for in-hospital arrests and 9% for in-ICU arrests. In total 585(53%) patients had an unfavourable neurological outcome. Compared to normoxemia, severe (Odds ratio [OR] 0.81, 95% confidence interval [CI] 0.50–1.30) and moderate hyperoxemia (OR 0.94 95%CI 0.69–1.27) did not associate with neurological outcome. Additionally, hyperoxemia had no association with mortality. In subgroup analyses there were no significant associations between severe hyperoxemia and outcomes regardless of cardiac arrest location, initial rhythm or time-to-ROSC.
We found no association between early post-arrest hyperoxemia and unfavourable outcome. Subgroup analysis found no differential effect depending on arrest location, initial rhythm or time-to-ROSC.