Associations Of Average Mean Arterial Oxygen Tension With Prognosis Of Patients Resuscitated From IHCA

ObjectiveWe sought to study the impact of average arterial oxygen tension?PaO₂?upon the first 24h after cardiac arrest in patients with in-hospital cardiac arrest.Methodswe performed a retrospective analysis in patients with cardiac arrest in ICU from May 2015 to October 2017.Of these patients,baseline demographic,clinical,laboratory,and clinical outcome data were recorded.The primary outcome of interest was survival in hospital.Secondary outcome of interest were good neurological outcome at 24h and hospital discharge.ResultsA total of 113 patients were included for analysis,of the 113 patients studied,average arterial oxygen tension?PaO₂?categorization included the following:PaO₂<60 mmHg?n=9?,PaO₂ of 60-120 mmHg?n=43?,PaO₂ of 120 to 200 mmHg?n=46?,and PaO₂?300 mmHg?n=15?.There were no statistically differences in the baseline data like gender,age,and basic disease.There were 49?43.3%?patients survived in hospital,15?13.3%?and 12?10.6%?patients have good neurologic outcome at 24h and discharge respectively.We found significantly difference between these groups in survial rate in hospital?P=0.02?,while there were no differences in the rates of good neurologic outcomes at 24h?P=0.637?and at discharge?P=0.680?.After adjusted for covariables like age,initial rhythme,CPR sustained time and Fi O₂,hypoxia?PaO₂<60 mmHg?and severe hyperoxia?PaO₂?300 mmHg?were associated with decreased survival rates in hospital(OR 0.005 95%CI?OR 0.005 95%CI?0.000,0.209?P=0.005;OR 0.062 95%CI?0.010,0.401?P=0.004?and mild hyperoxia?PaO₂ of 120 to 200 mmHg?was not?OR 0.490 95%CI?0.121,1.990?P=0.319?,while there were no relationship between any levels time-weighted mean arterial oxygen tension and good neurologic outcome at 24h and discharge repectively.We performed an analysis in patients concurrenced with respiratory diseases,and found that hypoxia and severe hyperoxia were associated with decreased survival rates in hospital?OR 0.026 95%CI?0.002,0.352?P=0.006;OR 0.099 95%CI?0.010,0.956?P=0.046?.There were no relationship between any levels time-weighted mean arterial oxygen tension and good neurologic outcome at24h and discharge repectively either.ConclusionsIn this study of patients sufferred cardiac arrest occurred in ICU,sever high mean PaO₂?>200mmHg?and hypoxia was associated with increased in-hospital mortality.We found no association between any levels of the time-weighted mean PaO₂ and good neurologic outcome at 24h and hospital discharge.In the subgroup analysis about patients concurrenced with respiratory diseases,we found the same outcomes.Based on previous studys and our research,we recommened that matain PaO₂ at60-200mmHg is reasonable.Given the limitations of this study,further studies are required to better understand these findings.