Introduction: Cardiac arrest is a common cause of death among patients undergoing maintenance hemodialysis; however, the prevalence and risk factors for cardiac arrest in the setting of acute kidney injury (AKI) are not studied in detail.
Methods: Patients who received hemodialysis for AKI between 2014 and 2024 were classified as those who experienced cardiac arrest during hemodialysis (group A) and patients who had cardiac arrest during hospitalization outside the hemodialysis session (group B). Logistic regression analysis was performed to determine the odds of cardiac arrest during the hemodialysis session versus outside the session.
Findings: Among the 1702 patients who received hemodialysis for AKI, 33 (0.02%) experienced cardiac arrest at the time of hemodialysis (group A), and 100 (0.06%) had cardiac arrest outside the session (group B). Previous history of atrial fibrillation was more common in group A (39% vs. 19%, p = 0.017). Groups were comparable in terms of oxygen or vasopressor requirement and baseline mean serum creatinine. Metabolic acidosis was more severe, and serum blood urea nitrogen and calcium levels were higher in group B (p < 0.05). Ultrafiltration rates were higher in group A than in group B (mean 10.6 mL/h/kg vs. 6.2 mL/h/kg, p < 0.001). There were more deaths in group A within the first 24 h following cardiac arrest (79% vs. 48%, p < 0.05); however, spontaneous recirculation and overall in-hospital mortality were comparable. In the multivariate regression model, atrial fibrillation (OR = 4.91, 95% CI 1.35-17.8, p = 0.016), lower pre-dialysis serum calcium levels (OR = 2.66, 95% CI 1.25-5.65, p = 0.011), and higher ultrafiltration volume (OR = 10.9, 95% CI 3.90-30.5, p < 0.001) were independently associated with an increased risk of cardiac arrest during hemodialysis sessions.
Discussion: History of atrial fibrillation, lower pre-dialysis serum calcium levels, and higher ultrafiltration volumes are associated with an increased risk of cardiac arrest during hemodialysis than cardiac arrest outside the hemodialysis session in the AKI setting.