Case: 

A 63 y/o M with known ESRD presents to your emergency department with a chief complaint of SOB. Patient is found to be clinically volume overloaded with a pulse ox of 89% and rales bilaterally. Laboratory results show hyperkalemia and uremia. The patient admits to missing his last four dialysis sessions. Nephrology was consulted and emergent dialysis was initiated in the ED with full resolution of respiratory distress. The patient is deemed appropriate for discharge by Nephrology. You are about to discharge the patient when the patient's nurse tells you the patient is now complaining of a headache, dizziness, and had one episode of vomiting. What is the diagnosis? 

Background:

Nearly 800,000 patients in the United States had ESRD in 2016 with 87% of these individuals using hemodialysis for renal replacement therapy. Thus, it is vital that emergency medicine doctors have an understanding of complications associated with hemodialysis. Dialysis disequilibrium syndrome is just one of many complications.

Dialysis Disequilibrium Syndrome:

A condition of cerebral edema secondary to osmotic fluid shifts that occur with dialysis.

In the most simple terms, the pathophysiology involves removing urea from blood too fast. As a result, urea remains elevated in the intracellular space relative to the intravascular space. This results in an osmotic gradient that leads to water entering cells. The ultimate result is cerebral edema.

Risk Factors:

First time dialysis session

High BUN

Children

Elderly

Preexisting cerebral edema

Symtoms:

Nausea/Vomiting

Headache

Confusion

Dizziness

Seizures

Coma
Death

Differential Diagnosis:

Hypovolemia

Electrolyte abnormalities

Hemolysis

Infection

Air embolism

Treatment:

Prevention is key – gradual rather than dramatic removal of urea

Slow blood flow rate to decrease urea clearance

Discontinue treatment including CRRT if on continuous therapy

Airway management if needed

Hyperventilation if concern for herniation

Mannitol if concern for herniation

Reference: Mistry K. Dialysis disequilibrium syndrome prevention and management. Int J NephrolRenovasc Dis. 2019;12:69–77. Published 2019 Apr 30. doi:10.2147/IJNRD.S165925