What is disequilibrium syndrome, also known as (Dialysis Disequilibrium Syndrome)?

From the Guidelines

Disequilibrium syndrome can be prevented by initiating dialysis gradually in high-risk patients, with shorter initial sessions and slower blood flow rates, as supported by the clinical practice guidelines for hemodialysis adequacy 1. To minimize the risk of disequilibrium syndrome, it is essential to consider the patient's individual factors, such as the severity of uremia and the presence of pre-existing neurological conditions.

• The condition develops when rapid removal of urea from the blood creates an osmotic gradient between the blood and brain, causing cerebral edema as water shifts into brain tissue.
• Symptoms of disequilibrium syndrome include dizziness, headache, nausea, vomiting, confusion, seizures, and in severe cases, coma.
• Treatment involves supportive care, including anticonvulsants for seizures and mannitol to reduce cerebral edema in severe cases.
• Prevention is key, and the use of equilibrated Kt/V (eKt/V) can help account for solute disequilibrium and minimize the risk of disequilibrium syndrome, as recommended by the KDOQI HD Work Group 1.
• While other studies have reported on various symptoms and management strategies in patients with chronic kidney disease, such as uremic pruritus, sleep disorders, and depression 1, these are not directly related to the prevention and treatment of disequilibrium syndrome.
• The most recent and highest quality study on this topic is the clinical practice guidelines for hemodialysis adequacy, update 2006 1, which provides the best evidence for preventing and managing disequilibrium syndrome.

From the Research

Definition and Overview

• Dialysis disequilibrium syndrome (DDS) is a clinical constellation of neurologic symptoms and signs occurring during or shortly following dialysis, especially when dialysis is first initiated 2.
• It is a diagnosis of exclusion occurring in those that are uremic and hyperosmolar, in whom rapid correction with renal replacement therapy leads to cerebral edema and raised intracranial pressure with resultant clinical neurologic manifestations 2.

Pathogenesis and Risk Factors

• The syndrome is associated with the rapid removal of urea during hemodialysis, resulting in an osmotic gradient between the brain and the plasma 3.
• Cerebral edema and increased intracranial pressure are the primary contributing factors to this syndrome 4.
• Patients with elevated blood urea nitrogen levels above 100 mg/dL are at higher risk of developing DDS, especially when commencing dialysis 5.

Clinical Features and Diagnosis

• The signs and symptoms of DDS vary widely from restlessness and headache to coma and death 4.
• Neurological symptoms such as headache, nausea, vomiting, muscle cramps, tremors, disturbed consciousness, and convulsions can occur due to brain edema 3.
• Diagnosis of DDS can be challenging due to nonspecific symptoms, and prompt recognition is crucial to prevent severe outcomes 5.

Prevention and Management

• Measures to avoid the development of DDS are crucial, as treatment of the syndrome once it has developed is rarely successful 4.
• Preventive measures include identifying patients at risk, using slower dialysis rates, and avoiding excessive urea removal 2.
• Management of DDS involves balancing the osmotic gradient and preventing severe outcomes, such as cerebral edema and death, using treatments like 3% hypertonic saline or mannitol 6, 5.