Predictive factors of adverse clinical outcomes among patients receiving emergency hemodialysis in emergency department

Background: It is well known that patients receiving emergency hemodialysis (HD) in the emergency department (ED) are associated with poor outcomes. This study aimed to search for predictive factors for adverse clinical outcomes among patients receiving emergency HD within 24 hours of visit to ED. We specifically analysed those cases receiving emergency HD both in the ED and non-ED settings. Methods: Retrospective observational study among all patients admitted to the ED of a tertiary teaching hospital and underwent emergency HD for any medical causes apart from trauma within 24 hours of attendance. The primary and secondary outcomes were 60-day mortality and; need for mechanical ventilation & intensive care unit (ICU) admission respectively. Binary logistic regression analysis was used to identify predictive factors for the adverse clinical outcomes. Results: A total of 177 patients were recruited. Categorical analysis found that majority of patients attending ED requiring emergency HD has no known history of HD, higher proportion of fluid overload features and had a significant preponderance requiring mechanical ventilation and succumbed within 60 days (P<0.05). Severe metabolic acidosis [adjusted odds ratio (OR) 3.01; 95% confidence interval (CI): 1.29, 7.00; P=0.10], severe hyperkalemia [adjusted OR 2.98 (95% CI: 1.16, 7.60); P=0.002] and mechanical ventilation in ED [adjusted OR 3.53 (95% CI: 1.59, 7.82); P=0.002] significantly predicted 60-day mortality [area under the curve (AUC) 0.74; (95% CI: 0.64, 0.84); P<0.001]. Significant predictive factors for ICU admission include those presented with severe metabolic acidosis [adjusted OR 2.78 (95% CI: 1.10, 7.01); P=0.03] whereas performing HD in ED [adjusted OR 0.33 (95% CI: 0.14, 0.79); P=0.01] and known case of regular HD [adjusted OR 0.21 (95% CI: 0.06, 0.70); P=0.01] had lower odd for ICU admission [AUC 0.77 (95% CI: 0.68, 0.87); P<0.001]. Predictive factors for mechanical ventilation were shortness of breath [adjusted OR 4.95 (95% CI: 2.25, 10.920); P<0.05] and severe hyperkalemia at presentation [adjusted OR 2.95 (95% CI: 1.16, 7.52); P=0.02] with AUC of 0.72 (95% CI: 0.64, 0.79); P<0.05. Conclusions: Severe metabolic acidosis, hyperkalemia and mechanically ventilated patients were significantly associated with adverse outcomes among patients attended ED with acute renal failure requiring emergency HD. Hence more precautions should be taken in managing cases with these clinical characteristics in the ED.