How to manage refractory hypertension in anuric (Kidney Disease: Improving Global Outcomes stage V) patients with end-stage renal disease (ESRD)?

Management of Refractory Hypertension in Anuric KDIGO Stage V Patients

Volume control through aggressive ultrafiltration targeting euvolemia is the primary and most critical intervention for refractory hypertension in anuric ESRD patients, with antihypertensive medications serving as adjunctive therapy only after volume optimization has been achieved. 1

Primary Strategy: Volume Management

Ultrafiltration Optimization

• Target net ultrafiltration of at least 1.0 L per day in anuric patients to achieve euvolemia, as this is the evidence-based cornerstone of blood pressure control 1
• Implement a slow, gradual approach to achieving dry weight for most patients, but consider more aggressive ultrafiltration specifically for those with cardiac failure or severe complication-associated hypertension 2, 3
• Extend dialysis treatment time beyond the standard 4 hours three times weekly if patients cannot tolerate standard ultrafiltration rates, as this allows adequate fluid removal without hemodynamic instability 2
• Recognize that the relationship between extracellular volume and blood pressure may be sigmoidal rather than linear, requiring individualized fluid removal targets rather than uniform protocols 2

Dietary Sodium Restriction

• Restrict dietary sodium intake to no more than 2.0 g (85 mmol) of sodium per day, which translates to less than 5 g of sodium chloride 1, 3
• This restriction is critical because sodium drives water retention and volume expansion in anuric patients who cannot excrete excess sodium 1

Critical Pitfall to Avoid

• Avoid using sodium profiling or high dialysate sodium concentrations, as these increase positive sodium balance and worsen volume overload 1

Secondary Strategy: Antihypertensive Medications

When to Initiate Pharmacotherapy

• Add antihypertensive medications only after nonpharmacologic volume control measures have been optimized and blood pressure remains above target 1
• If blood pressure is well controlled and antihypertensive medications interfere with ultrafiltration, reduce medications to allow for enhanced fluid removal 1

First-Line Medication Classes

ACE inhibitors, ARBs, and calcium channel blockers are reasonable first-line agents, as they are considered first-line in the general population and can be applied to dialysis patients 1, 4

• ACE inhibitors or ARBs provide cardioprotective effects independent of blood pressure reduction, though their benefit in anuric patients (without residual kidney function to preserve) is primarily for blood pressure control 1, 4
• Calcium channel blockers (such as amlodipine) are effective peripheral arterial vasodilators that reduce peripheral vascular resistance without significant effects on heart rate or cardiac conduction 5
• Beta-blockers are reasonable alternatives, particularly nondialyzable agents like propranolol or carvedilol 1, 4

Medication Selection Based on Dialyzability

For patients prone to intradialytic hypotension:

• Prefer dialyzable medications (atenolol, metoprolol) that are removed during dialysis sessions, providing protection between treatments while minimizing intradialytic hypotension risk 1, 4

For patients with intradialytic hypertension:

• Use nondialyzable medications (propranolol, amlodipine) that maintain therapeutic levels throughout the dialysis session 1, 4
• Nondialyzable beta-blockers may provide superior mortality benefit by maintaining intradialytic protection against arrhythmias 1

Dosing Strategy for Nonadherent Patients

• Consider thrice-weekly dosing immediately after dialysis sessions, as studies demonstrate robust blood pressure-lowering effects with this simplified regimen 4

Monitoring and Assessment

Blood Pressure Measurement

• Obtain out-of-unit blood pressure measurements (home or ambulatory monitoring) rather than relying solely on dialysis unit readings, as these correlate better with cardiovascular outcomes 1
• Monitor for intradialytic hypertension, defined as systolic blood pressure increase >10 mmHg from pre- to post-dialysis into the hypertensive range in at least 4 of 6 consecutive treatments 1

Volume Status Assessment

• Perform critical assessment of dry weight through clinical examination focusing on edema, blood pressure patterns, and respiratory symptoms 2
• Recognize the "lag phenomenon" where blood pressure may continue to decrease for months after achieving euvolemia 2

Rescue Therapy for Truly Refractory Cases

Bilateral nephrectomy should be considered as a last-resort rescue therapy when hypertension remains refractory despite maximal medical therapy (multiple antihypertensive agents at maximum doses) and optimal volume control through dialysis 6, 7

• This surgical option has demonstrated significant improvement in blood pressure control and reduction in antihypertensive medication requirements in case reports 6, 7
• Consider this option particularly when patients experience multiple life-threatening hypertensive crises despite aggressive medical management 6

Common Pitfalls

• Do not prioritize increasing dialysis dose (Kt/V) alone without addressing volume control, as peritoneal or hemodialysis small-solute clearance shows no significant association with outcome in anuric patients—ultrafiltration is more important 1
• Avoid excessive ultrafiltration rates that cause intradialytic hypotension, as this can lead to inadequate volume removal and perpetuate hypertension 1, 2
• Do not focus exclusively on dialysis-based interventions without addressing dietary sodium and fluid intake between sessions, as this undermines volume control efforts 2