What is the recommended management for hypertension in patients undergoing dialysis?

Managing Hypertension in Dialysis Patients

Primary Strategy: Volume Control Before Medications

The cornerstone of hypertension management in dialysis patients is achieving true dry weight through adequate ultrafiltration and strict dietary sodium restriction to 2-3 g/day, with pharmacological therapy reserved only if blood pressure remains uncontrolled after 4-12 weeks of optimized volume management. 1, 2

Volume Management Approach

• Implement strict dietary sodium restriction to 2-3 g/day with regular dietitian counseling every 3 months 3, 1, 2
• Pursue gradual dry weight reduction (0.1 kg per 10 kg body weight) through adequate ultrafiltration, even if this causes transient intradialytic symptoms 1, 2
• Consider extended dialysis time (at least 4 hours) 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, 4
• Use lower dialysate sodium concentrations (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

Blood Pressure Targets

Target predialysis blood pressure <140/90 mmHg and postdialysis blood pressure <130/80 mmHg to minimize left ventricular hypertrophy and mortality. 3, 1, 2

Measurement Considerations

• Measure blood pressure with the patient seated quietly for at least 5 minutes, feet on floor, arm supported at heart level 1, 2
• In patients who have undergone multiple vascular access procedures in both arms, measure blood pressure in the thighs or legs using appropriate cuff size in the supine position 3, 2
• Do not rely solely on predialysis or postdialysis measurements, as these correlate poorly with interdialytic ambulatory blood pressure 1, 2, 5
• Consider home blood pressure monitoring or 44-hour ambulatory blood pressure monitoring for more accurate assessment 2, 6

Pharmacological Management (Only After Volume Optimization)

First-Line Agents: ACE Inhibitors or ARBs

If blood pressure remains uncontrolled after 4-12 weeks of optimized ultrafiltration and sodium restriction, initiate ACE inhibitors or ARBs as first-line pharmacological therapy. 3, 1, 2

• ACE inhibitors and ARBs are preferred because they cause greater regression of left ventricular hypertrophy, reduce sympathetic nerve activity, improve endothelial function, and are associated with decreased mortality 3, 2, 7
• For patients on hemodialysis with creatinine clearance <10 mL/min, start lisinopril at 2.5 mg once daily and uptitrate as tolerated to a maximum of 40 mg daily 8

Second-Line Agents: Beta-Blockers

Add beta-blockers (carvedilol, labetalol, bisoprolol) particularly if the patient has prior myocardial infarction, established coronary artery disease, or heart failure. 1, 2

• Beta-blockers are uniformly protective in dialysis patients and help control sympathetic nervous system overactivity 2, 9
• Consider the dialyzability of beta-blockers when selecting agents, as highly dialyzable agents like metoprolol may have reduced efficacy during dialysis periods 2

Third-Line Agents: Calcium Channel Blockers

Add long-acting dihydropyridine calcium channel blockers (amlodipine) if blood pressure remains uncontrolled. 1, 2

• Calcium channel blockers have demonstrated efficacy in reducing cardiovascular events and mortality in hemodialysis patients with hypertension 2, 10

Medication Timing

Administer antihypertensive drugs preferentially at night to reduce nocturnal blood pressure surge and minimize intradialytic hypotension that may occur when drugs are taken the morning before dialysis. 3, 2, 6

Resistant Hypertension Management

Define resistant hypertension as blood pressure remaining above 140/90 mmHg after achieving dry weight and using an adequate triple-drug regimen at near-maximal doses from different classes (beta-blocker, long-acting dihydropyridine calcium channel blocker, and renin-angiotensin system inhibitor). 1, 4

Evaluation and Management

• Before intensifying antihypertensive therapy, reassess volume status and adequacy of dialysis time (at least 4 hours per session) 4
• Evaluate for secondary causes including renal artery stenosis, obstructive sleep apnea, primary hyperaldosteronism, and medication/substance interference 1
• Consider large doses of potent loop diuretics (such as furosemide) in patients with residual kidney function to promote sodium and water loss 2

Common Pitfalls to Avoid

• Do not initiate or increase antihypertensive medications without first assessing and optimizing volume status, as volume overload is the most important treatable cause of resistance 1, 2, 4
• Do not rely on in-center blood pressure measurements alone, as they poorly reflect true interdialytic blood pressure control 1, 6, 5
• Be cautious with excessive blood pressure reduction, as a U-shaped relationship exists between blood pressure and mortality in dialysis patients, with low predialysis systolic BP (<110 mmHg) and diastolic BP (<70 mmHg) associated with increased mortality 6, 5

Special Considerations

• Monitor for orthostatic hypotension, particularly in elderly patients, and treat with caution if standing systolic BP is <110 mmHg 2, 6
• Recognize that erythropoietin therapy can worsen hypertension, particularly in patients with pre-existing hypertension, severe anemia, or rapid anemia correction 1, 2, 6
• During hemodialysis sessions, maintain mean arterial pressure ≥65 mmHg to ensure adequate tissue perfusion 2
• Use a stepped-care approach in elderly patients rather than starting with 2-drug therapy, with close monitoring for adverse effects such as acute kidney injury, electrolyte abnormalities, and hypotension 6