Effect of Blood Pressure Variability on Outcomes in Emergency Patients with Intracranial Hemorrhage

INTRODUCTION: Patients with spontaneous intracranial hemorrhage (sICH) have high mortality and morbidity, which are associated with blood pressure variability. Additionally, blood pressure variability is associated with acute kidney injury (AKI) in critically ill patients, but its association with sICH patients in emergency departments (ED) is unclear. Our study investigated the association between blood pressure variability in the ED and the risk of developing AKI during sICH patients’ hospital stay. METHODS: We retrospectively analyzed patients with sICH, including those with subarachnoid and intraparenchymal hemorrhage, who were admitted from any ED and who received an external ventricular drain at our academic center. Patients were identified by the International Classification of Diseases, Ninth Revision (ICD-9). Outcomes were the development of AKI, mortality, and being discharged home. We performed multivariable logistic regressions to measure the association of clinical factors and interventions with outcomes. RESULTS: We analyzed the records of 259 patients: 71 (27%) patients developed AKI, and 59 (23%) patients died. Mean age (± standard deviation [SD]) was 58 (14) years, and 150 (58%) were female. Patients with AKI had significantly higher blood pressure variability than patients without AKI. Each millimeter of mercury increment in one component of blood pressure variability, SD in systolic blood pressure (SBP(SD)), was significantly associated with 2% increased likelihood of developing AKI (odds ratio [OR] 1.02, 95% confidence interval [CI], 1.005–1.03, p = 0.007). Initiating nicardipine infusion in the ED (OR 0.35, 95% CI, 0.15–0.77, p = 0.01) was associated with lower odds of in-hospital mortality. No ED interventions or blood pressure variability components were associated with patients’ likelihood to be discharged home. CONCLUSION: Our study suggests that greater SBP(SD) during patients’ ED stay is associated with higher likelihood of AKI, while starting nicardipine infusion is associated with lower odds of in-hospital mortality. Further studies about interventions and outcomes of patients with sICH in the ED are needed to confirm our observations.