Abstract: PUB065
A Forgotten Risk: Dialysis Disequilibrium Syndrome After Missed Hemodialysis Sessions
Session Information
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Bhandari, Sanjeev, New York City Health and Hospitals Jacobi, New York, New York, United States
- Shastri, Rujul Piyush, New York City Health and Hospitals Jacobi, New York, New York, United States
- Varma, Nidhi, New York City Health and Hospitals Jacobi, New York, New York, United States
- Anis, Kisra, New York City Health and Hospitals Jacobi, New York, New York, United States
Introduction
Dialysis disequilibrium syndrome (DDS) is a neurological complication of hemodialysis ranging from mild symptoms to seizures, coma, and death. It occurs during or shortly after hemodialysis, most commonly in patients newly initiating dialysis or resuming treatment after missed sessions. Rapid urea clearance from blood outpaces its removal from the brain, creating an osmotic gradient that drives water into brain tissue and causes cerebral edema - the "reverse urea hypothesis." We report a case of DDS in a patient who resumed hemodialysis after missing two scheduled sessions.
Case Description
A 76-year-old male with DM2, hypertension, and ESRD on thrice-weekly HD for 5 months presented with altered mental status and generalized tonic-clonic seizures after completing HD that day. He became somnolent with nonsensical speech toward the end of his 3-hour treatment before seizing. He had missed two HD sessions due to travel. On arrival, BP was 186/74 mmHg with ongoing seizure activity. Labs showed BUN 20 mg/dL, sodium 137 mEq/L, potassium 4.0 mEq/L, glucose 125 mg/dL, and calcium 9 mg/dL. No hypoglycemia or hemodynamic instability occurred during dialysis.
CT, MRI brain, and lumbar puncture were unremarkable. EEG demonstrated mild-moderate toxic-metabolic encephalopathy. DDS was diagnosed based on clinical presentation and exclusion of other etiologies. Pre-dialysis BUN was 87 mg/dL, yielding a urea reduction ratio (URR) of 77%, well above the 40% threshold recommended when resuming HD after missed sessions. Ultrafiltration rate was 15.3 mL/kg/h (recommended maximum 13 mL/kg/h), with BFR 400 mL/min and DFR 800 mL/min. The patient improved with supportive care, received gentle HD on day 5 (BFR 300 mL/min, DFR 500 mL/min), and was discharged on day 6.
Discussion
Multiple factors predisposed this patient to DDS: missed sessions causing elevated pre-dialysis BUN (87 mg/dL), excessive URR (77% vs. recommended 40%), high UFR (15.3 mL/kg/h), and aggressive BFR/DFR settings maximizing urea clearance. In high-risk patients it can be prevented with "gentle" dialysis: reduced BFR (≤200–300 mL/min), lower DFR, shorter sessions, smaller dialyzers, and lower URR target around 40% with gradual escalation.