How can I treat hypotension in a patient undergoing peritoneal (PD) dialysis?

Managing Hypotension in Peritoneal Dialysis Patients

The primary approach to hypotension in PD patients is to identify and correct the underlying cause—most commonly hypovolemia from excessive ultrafiltration—by reducing UF volume through adjusting PD solutions, omitting dwells, liberalizing salt intake, and discontinuing antihypertensive medications. 1

Immediate Assessment and Etiology

Hypotension in PD patients stems from four main causes that require different management strategies 2:

• Hypovolemia (39.5% of cases): Excessive ultrafiltration, inadequate oral intake, or failure to adjust prescription with decreased dietary intake 1, 2
• Cardiac dysfunction/CHF (18.5% of cases): Low cardiac output states with poor prognosis (65% mortality) 2
• Antihypertensive medications (13.6% of cases): Failure to adjust medications as volume status changes 1, 2
• Unknown etiology (28.4% of cases): Poor response to interventions with 65% mortality 2

The hypovolemic group responds best to treatment with prompt improvement, while cardiac dysfunction and unknown etiology groups have significantly worse outcomes 2.

First-Line Management: Reduce Ultrafiltration

Adjust the PD prescription to decrease fluid removal 1:

• Switch to less hypertonic glucose solutions: Replace 2.5% or 4.25% dextrose with 1.5% dextrose exchanges to reduce UF 1
• Change icodextrin to conventional 1.5% glucose solution: Icodextrin provides sustained UF that may be excessive in hypotensive patients 1
• Omit dwells strategically:
  • In automated PD (APD): eliminate the day dwell if residual kidney function (RKF) is adequate 1
  • In continuous ambulatory PD (CAPD): omit the night dwell without compromising clearance 1

Volume Expansion Strategies

• Liberalize salt intake: Increase dietary sodium to promote volume expansion 1
• Withhold or reduce antihypertensive medications: Discontinue or decrease doses, particularly in patients on multiple agents 1, 2
• Direct volume replacement: In acute symptomatic hypotension, consider intraperitoneal or intravenous fluid boluses 2

Special Considerations for Chronic Hypotension

Chronically hypotensive PD patients are particularly challenging and may require modality change 1:

• Increasing dialysis time (the standard HD recommendation) is less applicable to continuous PD 1
• These patients may tolerate PD better than HD, though further study is needed to confirm whether outcomes improve after modality transition 1
• Chronic hypovolemia can paradoxically coexist with accelerated hypertension due to renin-angiotensin system activation—correction of hypovolemia resolves both the supine hypertension and orthostatic hypotension 3

Pharmacologic Support (Limited Role)

• Midodrine: FDA-approved for symptomatic orthostatic hypotension, though evidence specific to PD patients is lacking 4
  • Indicated only when lives are considerably impaired despite standard clinical care 4
  • Can cause marked supine hypertension (>200 mmHg systolic) 4
  • Should be continued only if patients report significant symptomatic improvement 4

Preserve Residual Kidney Function

• Avoid intradialytic hypotension: Hypotension may harm RKF, which is strongly associated with better volume control and outcomes 1, 5
• Minimize nephrotoxic exposures: Protect remaining kidney function as it provides critical volume regulation 5

Critical Pitfalls to Avoid

• Do not use hypertonic glucose solutions to compensate: Attempting to maintain clearance with aggressive UF in hypotensive patients worsens the problem 1, 2
• Never ignore negative ultrafiltration: If dwells are absorbing fluid rather than removing it, this directly worsens hypovolemia 6
• Reassess target weight carefully: Especially in patients with cardiac failure, the prescribed "dry weight" may be too low 2
• Do not assume all hypotension is volume-related: 47% of hypotensive PD patients have cardiac dysfunction or unknown causes with poor prognosis requiring different management 2

Monitoring Response

• Patients with hypovolemia typically respond promptly to fluid replacement and prescription adjustments 2
• Those with cardiac dysfunction or unknown etiology show only 40% improvement with appropriate intervention and require closer monitoring 2
• If hypotension persists despite reducing UF and liberalizing salt, consider cardiac evaluation and potential modality change 1, 2