DIALYSIS DISEQUILIBRIUM SYNDROME: A RARE CAUSE OF DELIRIUM IN THE ICU

Abstract

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Delirium is common in the hospital setting with rates up to 70% in the medical intensive care unit. It can be due to multiple etiologies. Here we describe a case of dialysis disequilibrium syndrome (DDS) associated with hemodialysis for acute hyperkalemia. CASE PRESENTATION: A 55 year-old male with past medical history of heart failure, diabetes mellitus and end-stage renal disease presented to the emergency room after a mechanical fall. His last hemodialysis was 2 days prior. On examination, he was alert and oriented to time, place, and person without headache, nausea or vomiting. Laboratory values were notable for a sodium of 140 mEq/L, potassium of 7.3 mEq/L, BUN 114 mg/dL. EKG showed peaked T waves. He was admitted to the MICU for acute hyperkalemia and urgent hemodialysis at a blood flow rate of 400ml/minute for 3.5 hours with 1.6L of ultrafiltration. Three hours after completion of dialysis, he became confused and delirious. Over the next few hours, he became more agitated with incomprehensible speech and inability to answer questions appropriately. Repeat labs showed a sodium of 136 mEq/L, BUN of 25 mg/dL, Ammonia of 36 umol/L and glucose of 125 mg/dl. CT head was performed to rule out subdural hematoma in the setting of a fall, however, it was normal. Toxicology screen as well as infectious work up were negative. Given the acute onset of mental status changes after hemodialysis with a drastic decrease in BUN, and excluding all possible causes, a working diagnosis of Dialysis Disequilibrium Syndrome was made. Dialysis was held for one day with improvement in patient's mental status. He was able to follow commands without any delirium. BUN showed a steady increase from 25 to 64 mg/dL. Hemodialysis was re-initiated at a slower blood flow rate of 200 ml/minute which the patient tolerated without any complications and no further episodes of delirium. DISCUSSION: DDS is caused by water movement into the brain due to a transient osmotic gradient from the rapid removal of small solutes such as urea, which causes cerebral edema. It is generally seen in patients undergoing dialysis for the first time or if they are undergoing dialysis after a long period of time. Most of the symptoms are self-limited. However, one must be cautious to restart hemodialysis at a slower flow rate since there have been cases that resulted in death. CONCLUSIONS: DDS is an increasingly rare syndrome and one must consider this after excluding all other causes of acute delirium. Early detection and management is associated with favorable outcomes. Reference #1: Mistry K. Dialysis disequilibrium syndrome prevention and management. Int J Nephrol Renovasc Dis. 2019;12:69-77 DISCLOSURES: No relevant relationships by Hung-I Liao, source=Web Response No relevant relationships by Avantika Nathani, source=Web Response