How to manage hypertension (high blood pressure) in a patient undergoing hemodialysis?

Management of Hypertension During Hemodialysis

Hypertension in hemodialysis patients should be managed primarily through aggressive volume control—achieving true dry weight via ultrafiltration and strict sodium restriction (2-3 g/day)—before escalating antihypertensive medications, with target blood pressures of <140/90 mmHg predialysis and <130/80 mmHg postdialysis. 1

Primary Strategy: Volume Management First

The fundamental approach recognizes that volume overload, not inadequate medication, drives hypertension in 60-90% of hemodialysis patients. 2, 3

Sodium and Fluid Control

• Implement strict dietary sodium restriction to 2-3 g/day (ideally <1,500 mg/day) with regular dietitian counseling every 3 months 1, 2
• Increase ultrafiltration during dialysis sessions to systematically reduce dry weight, even if this requires extending dialysis time beyond standard 4-hour sessions 1, 2, 3
• Consider longer dialysis sessions or increased frequency (>3 treatments per week), as the Tassin experience demonstrated that 89% of hypertensive patients no longer required antihypertensive medications after 3 months of long, slow dialysis combined with sodium restriction 2
• Use low-sodium dialysate (around 135 mmol/L rather than 140 mmol/L) to achieve proper volume control 2
• Avoid high dialysate sodium concentration and sodium profiling, as these aggravate thirst, fluid gain, and hypertension 2

Critical Pitfall to Avoid

Do not intensify pharmacotherapy before optimizing volume status over 4-12 weeks, as this is the most common error in managing dialysis-associated hypertension 2, 3. Gradual dry weight reduction (0.1 kg per 10 kg body weight) over this period reduces ambulatory blood pressure by approximately 7 mmHg while minimizing adverse events 2.

Blood Pressure Measurement and Targets

Proper Assessment

• Confirm accurate BP measurement using proper technique: patient seated quietly for 5 minutes, feet on floor, arm supported at heart level 2
• In patients with multiple vascular access procedures in both arms, measure BP in thighs or legs using appropriate cuff size in supine position 1, 2
• Obtain home BP monitoring or 44-hour interdialytic ambulatory BP monitoring, as in-center measurements correlate poorly with true BP and may miss white-coat hypertension 2, 3

Target Blood Pressures

• Predialysis BP: <140/90 mmHg 1, 2, 3
• Postdialysis BP: <130/80 mmHg 1, 3
• During dialysis sessions: maintain MAP ≥65 mmHg to ensure adequate tissue perfusion while avoiding increased mortality associated with excessive hypotension 2

Important caveat: A U-shaped relationship exists between blood pressure and mortality in dialysis patients 2. Low predialysis systolic BP (<110 mmHg) and diastolic BP (<70 mmHg) are associated with increased mortality, primarily from severe heart failure or coronary artery disease 4.

Pharmacological Management Algorithm

If volume control is insufficient after 4-12 weeks of optimized ultrafiltration and sodium restriction, initiate medications using this stepwise approach:

First-Line: ACE Inhibitors or ARBs

Start with ACE inhibitors (benazepril, fosinopril) or ARBs as initial therapy, as they cause greater regression of left ventricular hypertrophy, reduce sympathetic nerve activity, improve endothelial function, and are associated with decreased mortality in dialysis patients 1, 2, 5, 3

• Choose non-dialyzable ACE inhibitors (benazepril, fosinopril) over dialyzable ones (enalapril, ramipril, lisinopril) to maintain consistent drug levels 5, 3
• Note: Lisinopril is dialyzable and requires dose adjustment in hemodialysis patients 6

Second-Line: Beta-Blockers

Add beta-blockers (carvedilol, labetalol, or bisoprolol) particularly if the patient has prior myocardial infarction, coronary artery disease, or heart failure, as they are associated with decreased mortality in chronic kidney disease 2, 5, 3

• Prefer non-dialyzable beta-blockers (carvedilol, labetalol) over highly dialyzable ones (metoprolol) to avoid reduced efficacy during dialysis periods and potential increased mortality risk 2

Third-Line: Calcium Channel Blockers

Add long-acting dihydropyridine calcium channel blockers (amlodipine), as they are associated with decreased total and cardiovascular mortality in observational studies 2, 3

• Non-dihydropyridine CCBs were associated with reduced cardiovascular death (hazard ratio 0.78) in dialysis patients 7

Medication Timing

Administer all antihypertensive drugs preferentially at night to reduce nocturnal BP surge and minimize intradialytic hypotension that may occur when drugs are taken the morning before dialysis 1, 2

Resistant Hypertension Management

If BP remains uncontrolled despite achieving dry weight and using three antihypertensive agents from different classes at near-maximal doses:

Fourth-Line Options

• Add low-dose spironolactone (preferred fourth agent); if not tolerated, substitute eplerenone or add amiloride 5
• Consider hydralazine 25 mg three times daily, titrating upward to maximum dose 5
• For severe refractory cases, consider minoxidil 2.5 mg two to three times daily (requires concomitant beta-blocker and loop diuretic) 5

Evaluate Secondary Causes

Screen for renal artery stenosis, obstructive sleep apnea, primary hyperaldosteronism, and medication/substance interference 5

Last Resort Options

• Consider switching from hemodialysis to continuous ambulatory peritoneal dialysis for better volume control 5
• Catheter-based renal denervation or surgical/embolic bilateral nephrectomy as final options 5

Special Considerations

Monitoring During Treatment

• Monitor for orthostatic hypotension (drop ≥15 mmHg systolic or ≥10 mmHg diastolic after standing 2 minutes) during aggressive ultrafiltration 1, 3
• Watch for intradialytic hypotension—any symptomatic BP decrease or nadir intradialytic systolic BP <90 mmHg should prompt reassessment of ultrafiltration rate, dialysis time, and medications 3
• Monitor serum potassium periodically, as ACE inhibitors and ARBs can cause hyperkalemia, especially with renal insufficiency 6

Residual Kidney Function

Preserve residual kidney function when possible, as it is an important predictor of patient survival 2. Large doses of loop diuretics (furosemide) can promote sodium and water loss in patients with residual function, but use with caution 2.

Erythropoietin Therapy

Recognize that erythropoietin therapy can worsen hypertension, particularly in patients with pre-existing hypertension, severe anemia, or rapid anemia correction 2