Dialysis disequilibrium syndrome: an underdiagnosed condition? results from a monocentric observational study

Background Dialysis Disequilibrium Syndrome (DDS) is a neurological complication occurring during hemodialysis initiation whose pathogenesis remains incompletely understood. Limited prospective adult data exists on DDS incidence and risk factors. Methods We conducted a prospective observational study (February 2021–February 2022) including 48 patients initiating hemodialysis. DDS was assessed using a standardized severity score (0–3) before and after each of the first four sessions, defined as any increase in post-session score (Δ Score ≥ 1). Univariate and multivariate logistic regression identified risk factors. Results Among 48 patients (70.8% male, median age 67 years), 22.9% developed DDS with two patients experiencing multiple episodes. Univariate analysis identified centrally acting agent use (45.5% vs. 8.1%, P = 0.01), fluid overload (45.4% vs. 13.5%, P = 0.03), lower pre-dialysis pH (7.28 vs. 7.37, P = 0.04), and higher chloride (100 vs. 94 mmol/L, P = 0.01) as significant associations. Pre-dialysis urea was not associated with DDS (P = 0.15). Multivariate analysis identified intradialytic hypertension as an independent risk factor (OR = 4.43, 95% CI: 1.38–18.15, P = 0.01) occurring in 78.6% of DDS sessions versus 40.0% of non-DDS sessions. Conclusion DDS is a common complication (22.9% incidence) with intradialytic hypertension as the key independent predictor. Pre-dialysis urea concentration was not predictive. These findings suggest a pathophysiological model involving acid-base dynamics and intracranial pressure regulation rather than solute gradients alone. Future multicenter studies are needed to validate these findings and optimize dialysis initiation strategies.