National outcomes of in-hospital cardiopulmonary resuscitation in patients with acute kidney injury: Years 2005 - 2011

Background: There is paucity of data on the outcomes of in-hospital cardiopulmonary resuscitation (CPR) in patients with acute kidney injury (AKI). We analyzed the impact of acute kidney injury on in-hospital CPR-related outcomes. Materials and methods: We analyzed data from Nationwide Inpatient Sample (NIS 2005 - 2011) including patients with and without AKI who had undergone in-hospital CPR. Baseline characteristics, in-hospital complications and discharge outcomes were compared between the two groups. We determined the effect of AKI on length of hospital stay, discharge destination, hospital mortality, survival trends, and discharge to home. Results: 180,970 patients with primary or secondary diagnosis of AKI underwent in-hospital CPR compared to 323,620 patients without AKI. Unadjusted in-hospital mortality rates were higher in the AKI group (78.2 vs. 71.8%, p < 0.0001). After adjusting for age, sex, and potential confounders, patients in the AKI group had higher odds of mortality with odds ratio 1.3, 95% confidence interval 1.2 - 1.4, p < 0.0001. Survivors in the AKI group were more likely to be discharged to nursing homes and had higher mean hospitalization charges. In 2011 compared with 2005, there was an improved survival after CPR and higher rates of discharges to home. There was no significant change in the mean length of hospital stay between these time periods (p = 0.4). Conclusion: AKI independently increases the odds of in-hospital mortality and nursing home placement after in-hospital CPR. These data may facilitate CPR discussions and decision-making in critically ill patients.