Abstract 126: The Association Of Higher Or Lower Mean Arterial Pressure On Kidney Function After Cardiac Arrest: A Post-hoc Analysis Of The Comacare And Neuroprotect Trials

Abstract

Introduction: Acute kidney injury (AKI) denotes a sudden reduction in kidney function manifested by a rise in S-creatine levels and reduced urine output. Studies have suggested an association between AKI severity and outcomes after OHCA. Various criteria have been used to define AKI, the Kidney Disease Improving Global Outcomes (KDIGO) published in 2012 being the currently used tool. AKI is a feature of post-cardiac arrest syndrome.During post-CA syndrome, possible causes of renal damage are direct renal ischaemic-reperfusion injury and indirect renal damage characterized by the activation of inflammatory and coagulation pathways. Although the overall mortality rate after CA mainly relates to hypoxic-ischaemic brain injury, damage to other organs also has prognostic implications. Methods: Pooled post-hoc analysis of the COMACARE (NCT02698917) and NEUROPROTECT (NCT02541591) trials that randomized patients to lower (MAP 65-70 mmHg) or higher (MAP 80-100 mmHg) targets for the first 36 hours of post-CA intensive care. Kidney function was categorised using the KDIGO classification during the first five days after OHCA. We used Cox regression analysis to identify factors associated with AKI after OHCA. Results: A total of 227 patients were included: 115 in the high MAP group and 112 in the low MAP group. Eighty-six (38%) patients developed AKI during the first five days; 40 (47%) patients had AKI in the high MAP group and 46 (54%) in the low MAP group (p = 0.51). The mean creatinine and mean daily diuresis were 104 (95% CI 94-115) μmol/l and 1989 (95% CI 1829-2150) mL/day in the high MAP group and 111 (95% CI 99-122) μmol/l and 1677 (95% CI 1530-1824) mL/day in the low MAP group. In a Cox regression model, independent AKI predictors were previous hypertension (HR 1.72; 95% CI 1.07-2.78; p = 0.03), bystander cardiopulmonary resuscitation (hazard ratio [HR] 0.46; 95% CI 0.29-0.73; p < 0.01), shockable initial rhythm (HR 0.36; 95% CI 0.21-0.61; p ≤ 0.01), and time to ROSC (HR 1.04; 95% CI 1.02-1.06; p < 0.01) whereas high/low MAP was not an independent predictor of AKI. Conclusions: KDIGO1-staged AKI is common after CA and is associated with previous hypertension and CA factors. Targeting higher MAP after CA does not appear to influence the development of AKI.