Dialysis Disequilibrium Syndrome: Brain death following hemodialysis for metabolic acidosis and acute renal failure – A case report

Abstract

BackgroundDialysis disequilibrium syndrome (DDS) is the clinical phenomenon of acute neurologic symptoms attributed to cerebral edema that occurs during or following intermittent hemodialysis (HD). We describe a case of DDS-induced cerebral edema that resulted in irreversible brain injury and death following acute HD and review the relevant literature of the association of DDS and HD.Case PresentationA 22-year-old male with obstructive uropathy presented to hospital with severe sepsis syndrome secondary to pneumonia. Laboratory investigations included a pH of 6.95, PaCO2 10 mmHg, HCO3 2 mmol/L, serum sodium 132 mmol/L, serum osmolality 330 mosmol/kg, and urea 130 mg/dL (46.7 mmol/L). Diagnostic imaging demonstrated multifocal pneumonia, bilateral hydronephrosis and bladder wall thickening. During HD the patient became progressively obtunded. Repeat laboratory investigations showed pH 7.36, HCO3 19 mmol/L, potassium 1.8 mmol/L, and urea 38.4 mg/dL (13.7 mmol/L) (urea-reduction-ratio 71%). Following HD, spontaneous movements were absent with no pupillary or brainstem reflexes. Head CT-scan showed diffuse cerebral edema with effacement of basal cisterns and generalized loss of gray-white differentiation. Brain death was declared.ConclusionsDeath is a rare consequence of DDS in adults following HD. Several features may have predisposed this patient to DDS including: central nervous system adaptations from chronic kidney disease with efficient serum urea removal and correction of serum hyperosmolality; severe cerebral intracellular acidosis; relative hypercapnea; and post-HD hemodynamic instability with compounded cerebral ischemia.

Diffuse Leukoencephalopathy Associated with Dialysis Disequilibrium Syndrome

“…In reports of critical DDS cases, the complication of sepsis was thought to be the amplifier of cerebral edema through altered BBB permeability, which then led to brain herniation and death (3,4). In our patient, although brain imaging before the development of DDS was not performed, there was no past history of CNS disease.…”

“…Clinical features include headache, nausea, hypertension, seizures, and coma, leading to death in some severely affected patients (3,4). Since DDS is a clinical diagnosis, a radiological study is mainly used to exclude other central nervous system (CNS) diseases.…”

Dialysis Disequilibrium Syndrome: A Neurological Manifestation of Haemodialysis

“…Where haemodialysis is the only suitable option, a number of precautions can be taken to facilitate a gradual reduction in BUN and minimize the risk of DDS. These include intermittent haemodialysis using less efficient dialyzers with a smaller surface area and by reducing the duration and blood flow rate of dialysis (Bagshaw et al, 2004). It is also important to ensure that chronic dialysis patients do not undergo a sudden change in their dialysis regime perhaps implemented by a change in personal circumstances e.g.…”

Sepsis and Dialysis Disequilibrium Syndrome

“…This may alter the blood-brain permeability and may lead to DDS. 2 Overall, there are 2 main theories for the development of DDS. The first theory, also called the reverse osmotic shift, relates to the acute removal of urea, which occurs comparatively slower across the blood-brain barrier than in plasma, thus generating a reverse osmotic gradient.…”

“…He underwent his first episode of aggressive HD resulting in severe and fatal DDS. 2 If patients are on slow HD for several consecutive days, develops septic shock; and they are supposed to have sepsis-induced changes in the brain.…”