Abstract Body: Introduction: At least three out of four patients hospitalized for out-of-hospital cardiac arrest(OHCA) will not survive their stay. Although the use of intensive care units (ICUs) varies among different hospitals, there is no comprehensive data investigating the risk factors of death among them. We propose to investigate this further using the National Inpatient Sample (NIS).
Methods: Our sample consisted of patients admitted with a primary diagnosis code of OHCA and treated in the ICU based on ICD-10 codes used in previous studies. Our study expanded from 2016 to 2022. COVID-19 cases were removed from our selection. Multivariable regression models were created to investigate the potential roles of several clinically relevant comorbidities in predicting mortality risks.

Results: We had 83060 patients with OHCA who were admitted to the ICU. The overall death rate was estimated at 77.35%. No sex-based differences were noted for mortality(aOR in females: 1.009, 95% CI 0.933-1.014, p=0.826).Our analysis found that increasing age(aOR 1.012, 95% CI 1.009-1.014, p<0.01),liver cirrhosis(aOR 1.554, 95% CI 1.206-2.004, p<0.01), and diabetes(aOR 1.140, 95% CI 1.045-1.243, p<0.01) were linked with higher odds of death.Racial differences were noted as Blacks had lower odds of death than Whites(aOR 0.814, 95% CI 0.741-0.893, p<0.01), while Hispanics and Whites were comparable(aOR 1.018, 95% CI 0.885-1.171, p=0.800). Additionally, events of cardiogenic shock(aOR 1.381, 95% CI 1.217-1.568, p<0.01) and acute kidney injury(AKI)(aOR 1.233, 95% CI 1.141-1.332, p<0.01) were also predictors of poor outcomes. Patients who needed an intra-aortic balloon pump (IABP)(aOR 0.569, 95% CI 0.373-0.868, p<0.01)or Impella(aOR0.506, 95% CI 0.297-0.861, p=0.012) were more likely to survive. Those who died had a short stay of 2.62 days, while patients who survived were hospitalized for 10.93 days on average.
Conclusions: We confirm that OHCA patients treated in the ICU have a high mortality rate and early in-hospital death. Our findings further show the critical need for an early recognition of OHCA and the timely initiation of care.