Can renal failure manifest as disequilibrium?

Renal Failure and Disequilibrium Syndrome

Yes, renal failure can manifest as disequilibrium syndrome, particularly during rapid correction of uremia through hemodialysis in patients with advanced kidney disease.

What is Disequilibrium Syndrome?

Disequilibrium syndrome is a neurological complication characterized by neurological symptoms that occur during or after hemodialysis, primarily in patients with severe uremia. It represents a form of cerebral edema resulting from rapid changes in plasma osmolality during dialysis treatment.

Clinical Manifestations

• Mild symptoms: Headache, nausea, vomiting, restlessness, blurred vision
• Moderate symptoms: Disorientation, confusion, agitation
• Severe symptoms: Seizures, altered consciousness, coma

Pathophysiology

Two primary mechanisms contribute to disequilibrium syndrome:

1. Reverse urea effect: During rapid hemodialysis, urea is removed more quickly from the blood than from the cerebrospinal fluid (CSF) and brain tissue, creating an osmotic gradient that draws water into the brain, causing cerebral edema 1.

2. Intracerebral acidosis: Rapid correction of systemic acidosis during dialysis may lead to paradoxical CSF acidosis, contributing to cerebral edema 1.

Risk Factors

Patients at highest risk for developing disequilibrium syndrome include:

• First-time dialysis patients with severe uremia (BUN >100 mg/dL)
• Patients with pre-existing neurological conditions
• Pediatric patients
• Elderly patients
• Patients with chronic kidney disease stage 5 (GFR <15 mL/min) 1

Prevention Strategies

To prevent disequilibrium syndrome in high-risk patients:

1. Gentle initial dialysis:

   • Shorter initial sessions (2 hours instead of 4)
   • Lower blood flow rates
   • Smaller surface area dialyzers

2. Gradual urea reduction:

   • Target urea reduction ratio (URR) of approximately 25-30% for first dialysis 2
   • Avoid URR >50% in initial treatments

3. Dialysate modifications:

   • Use of sodium modeling (higher sodium concentration in dialysate)
   • Addition of osmotically active substances (mannitol or glucose) to dialysate

Management of Established Disequilibrium

For patients who develop disequilibrium syndrome:

1. Immediate measures:

   • Stop or slow dialysis if symptoms develop during treatment
   • Position patient with head elevated 30 degrees
   • Maintain airway, breathing, and circulation

2. Pharmacological interventions:

   • Anticonvulsants for seizure control
   • Mannitol (0.5-1.0 g/kg IV) to reduce cerebral edema
   • Hypertonic saline in severe cases

3. Supportive care:

   • Close neurological monitoring
   • Oxygen supplementation as needed

Special Considerations

Patients with Advanced CKD

In patients with CKD stage 5 (GFR <15 mL/min), the risk of disequilibrium is particularly high due to severe uremia and electrolyte abnormalities 1. These patients require especially careful initiation of dialysis.

Continuous Renal Replacement Therapy (CRRT)

CRRT may be preferred over intermittent hemodialysis in critically ill patients with AKI to avoid rapid shifts in osmolality and reduce the risk of disequilibrium 1.

Residual Renal Function

Monitoring residual renal function using fractional excretion of urea (FEUrea) can help guide dialysis prescription and potentially reduce the risk of disequilibrium syndrome 2.

Conclusion

Disequilibrium syndrome is a serious neurological complication that can manifest in patients with renal failure, particularly during initial hemodialysis treatments. Recognizing risk factors and implementing preventive strategies are essential to avoid this potentially life-threatening condition. The focus should be on gradual correction of uremia through gentle initial dialysis to minimize rapid shifts in osmolality and prevent cerebral edema.