Can peritoneal dialysis cause hypotension?

Peritoneal Dialysis and Hypotension

Yes, peritoneal dialysis can cause hypotension, occurring in approximately 12.8% of peritoneal dialysis patients, with four main mechanisms: hypovolemia (39.5%), congestive heart failure (18.5%), antihypertensive medications (13.6%), and idiopathic causes (28.4%). 1

Mechanisms of Hypotension in Peritoneal Dialysis

Hypotension during peritoneal dialysis (PD) occurs through several distinct mechanisms:

1. Excessive ultrafiltration:

   • Aggressive removal of fluid using hypertonic glucose solutions
   • Rapid fluid shifts from intravascular space
   • Failure to adjust PD prescription with decreased dietary intake 2

2. Medication-related:

   • Failure to adjust antihypertensive medications
   • Continued use of blood pressure medications despite volume contraction 2, 1

3. Dietary factors:

   • Overly stringent salt restriction leading to reduced plasma volume 2

4. Cardiac dysfunction:

   • Low cardiac output states
   • Congestive heart failure with poor response to volume expansion 1

Clinical Patterns and Consequences

Hypotension in PD patients can present in different patterns:

• Acute episodes during or shortly after exchanges
• Chronic persistent hypotension
• Orthostatic hypotension (positional)

The consequences of hypotension in PD patients are significant:

• Hypoperfusion of vital organs
• Increased mortality (particularly in CHF and idiopathic groups) 1
• Reduced quality of life
• Compromised residual kidney function

Management Strategies

1. Adjust PD Prescription

• Reduce ultrafiltration volume by using less hypertonic glucose solutions 2
• Consider changing icodextrin to conventional 1.5% glucose solution 2
• Omit day dwell (in APD) or night dwell (in CAPD) in those with significant residual kidney function 2

2. Medication Adjustments

• Withhold or reduce antihypertensive medications when hypotension develops 2, 1
• Review timing of antihypertensive administration to avoid pre-dialysis doses 3

3. Volume Management

• Liberalize salt intake in chronically hypotensive patients 2
• Ensure proper assessment of target weight, especially in patients with cardiac failure 1
• Implement volume expansion in hypovolemic patients 1

4. Consider Modality Change

• Patients with chronic hypotension may tolerate PD better than HD, though further study is needed to confirm whether outcomes improve after transition between modalities 2

Special Considerations

Differential Diagnosis

When evaluating hypotension in PD patients, consider:

• Autonomic neuropathy (including autoimmune autonomic ganglionopathy) 4
• Cardiac dysfunction
• Volume depletion
• Medication effects
• Adrenal insufficiency

Monitoring

• Regular assessment of volume status
• Blood pressure monitoring (including orthostatic measurements)
• Evaluation of residual kidney function every 4 months 3

Prevention Strategies

1. Careful use of antihypertensive medications with regular reassessment 1
2. Accurate evaluation of target weight, especially in patients with cardiac failure 1
3. Judicious use of hypertonic exchanges to prevent excessive fluid removal 1
4. Preservation of residual kidney function to help attenuate fluctuations in fluid balance 3

Pitfalls to Avoid

• Overaggressive ultrafiltration: Can lead to severe hypotension and organ hypoperfusion
• Failure to adjust medications: Continuing antihypertensives despite hypotension
• Misdiagnosis of volume status: Treating hypovolemia with further fluid removal
• Ignoring cardiac function: Heart failure patients require special consideration and may have poor response to standard interventions 1

Understanding the mechanisms and appropriate management of hypotension in PD patients is essential for optimizing outcomes and reducing morbidity and mortality in this vulnerable population.