How should hypertension be managed in a patient on chronic hemodialysis?

Management of Hypertension in Hemodialysis Patients

Hypertension management in hemodialysis patients must begin with aggressive volume control through dialysis prescription optimization—specifically by probing the target dry weight downward, increasing treatment time/frequency, and restricting dietary sodium to 2-3 g/day—before initiating or escalating antihypertensive medications. 1, 2

Primary Strategy: Volume Management Through Dialysis Optimization

Volume overload is the dominant driver of hypertension in hemodialysis patients, and addressing this is the foundation of treatment. 1, 3, 4

Step 1: Adjust Target Dry Weight

• Gently probe the prescribed target weight downward to identify true euvolemia, as most hypertensive HD patients are volume overloaded. 1, 2
• This requires systematic reduction of post-dialysis target weight by 0.2-0.5 kg increments while monitoring for intradialytic hypotension or symptoms. 2

Step 2: Modify Dialysis Prescription

• Increase treatment time and/or frequency (consider home HD or center-based nocturnal HD) to allow gentler ultrafiltration rates while achieving greater total fluid removal. 1, 2
• Longer dialysis sessions reduce cardiovascular stress from rapid ultrafiltration and improve BP control. 1, 3

Step 3: Reduce Interdialytic Weight Gain (IDWG)

• Restrict dietary sodium to 2-3 g/day through patient education, as sodium drives thirst and excessive fluid intake between sessions. 2, 5, 4, 6
• High dietary sodium creates a cycle of thirst, fluid gain, volume overload, and hypertension that cannot be overcome by dialysis alone. 4, 6

Step 4: Optimize Dialysate Sodium

• Consider using lower dialysate sodium concentration (135-138 mEq/L) to promote negative sodium balance during dialysis and reduce IDWG. 1, 5
• Never use dialysate sodium ≥140 mEq/L, as this increases thirst, IDWG, hypertension, and cardiovascular mortality. 5
• Be aware that lower dialysate sodium may increase intradialytic hypotension and cramping—monitor closely and adjust based on individual tolerance. 1
• Avoid sodium profiling, as it produces the same adverse effects as sustained high dialysate sodium. 5

Secondary Strategy: Pharmacological Management

Only after optimizing volume status should antihypertensive medications be initiated or escalated. 2, 3

Preferred Agents

• ACE inhibitors (e.g., lisinopril) or ARBs are first-line when medications are needed, as they cause greater regression of left ventricular hypertrophy and improve endothelial function. 2
• However, be aware that anaphylactoid reactions can occur with ACE inhibitors during dialysis with high-flux membranes—if this occurs, stop dialysis immediately, provide aggressive treatment, and consider switching to a different dialysis membrane or antihypertensive class. 7
• Calcium channel blockers are an alternative, particularly in patients unable to reduce dietary sodium intake or those with persistent hypertension despite RAS blockade. 6

Timing and Dosing Considerations

• Administer antihypertensive medications preferentially at night to reduce nocturnal BP surge and minimize intradialytic hypotension. 2
• Consider dialyzability of medications—non-dialyzable agents provide more consistent BP control across the dialysis cycle. 2, 3
• Monitor renal function periodically, as ACE inhibitors can cause acute renal failure, particularly in patients with residual kidney function. 7

Critical Monitoring and Safety

Blood Pressure Assessment

• Do not rely solely on pre- or post-dialysis BP measurements, as these show a J-shaped or U-shaped association with outcomes due to measurement inaccuracy and hemodynamic fluctuations. 3
• Home or ambulatory BP monitoring provides more accurate prognostic information and should guide treatment decisions. 3

Intradialytic Hypertension

• If systolic BP rises >10 mm Hg from pre- to post-dialysis, this defines intradialytic hypertension and warrants more extensive evaluation of volume status and BP management. 2

Common Pitfalls to Avoid

• Do not assume persistent hypertension means treatment failure—BP normalization may lag behind volume correction due to vascular remodeling. 5
• Do not use high dialysate sodium (≥140 mEq/L) to prevent intradialytic hypotension, as this creates a vicious cycle of thirst, weight gain, and worsening hypertension. 5
• Do not start or escalate antihypertensive medications without first optimizing volume status, as this misses the primary pathophysiology and increases risk of intradialytic hypotension. 1, 3, 6

Special Populations

• Patients with chronic hypotension may tolerate peritoneal dialysis better than hemodialysis, though further study is needed. 1
• Patients on erythropoietin-stimulating agents may have additional hypertension mechanisms beyond volume overload. 3

Algorithm Summary

1. Assess volume status → Probe dry weight downward by 0.2-0.5 kg increments 1, 2
2. Increase dialysis time/frequency → Aim for gentler ultrafiltration rates 1, 2
3. Restrict dietary sodium to 2-3 g/day → Reduce IDWG 2, 5, 4
4. Lower dialysate sodium to 135-138 mEq/L → Promote negative sodium balance 1, 5
5. If hypertension persists after volume optimization → Add ACE inhibitor/ARB (preferentially dosed at night) 2
6. Monitor with home/ambulatory BP → Adjust treatment based on out-of-dialysis BP patterns 3