Target MAP During Hemodialysis
The target mean arterial pressure (MAP) during hemodialysis should be maintained at approximately 65 mmHg or higher, with blood pressure goals of predialysis <140/90 mmHg and postdialysis <130/80 mmHg, prioritizing volume management through achievement of dry weight as the primary intervention before escalating antihypertensive medications. 1, 2
Primary Approach: Volume Management First
Volume control through ultrafiltration to achieve true dry weight must be the first-line strategy for blood pressure management during hemodialysis, not pharmacological intervention. 1, 2
- Extracellular volume expansion is the primary driver of hypertension in hemodialysis patients, making dry weight achievement essential before considering medication adjustments 1
- Gradual dry weight reduction (0.1 kg per 10 kg body weight) over 4-12 weeks reduces ambulatory blood pressure by approximately 7 mmHg while minimizing adverse events 1
- Bioimpedance-guided fluid management can reduce fluid overload by 2.0 L and decrease systolic blood pressure by 25 mmHg without increasing intradialytic complications 3
Specific MAP Targets and Rationale
During hemodialysis sessions, maintain MAP ≥65 mmHg to ensure adequate tissue perfusion while avoiding the increased mortality associated with excessive hypotension. 1
- Below MAP of 65 mmHg, tissue perfusion becomes linearly dependent on arterial pressure as autoregulation fails 1
- Targeting MAP of 65 mmHg versus 85 mmHg shows no mortality difference but reduces arrhythmia risk and vasopressor requirements 1
- Post-dialytic drops in systolic blood pressure up to 30 mmHg are associated with improved survival, but greater decreases correlate with higher mortality 1
Blood Pressure Measurement Technique
Measure blood pressure with the patient seated quietly for at least 5 minutes, feet on floor, arm supported at heart level, avoiding the access arm. 2
- In patients with bilateral vascular access procedures, measure blood pressure in thighs or legs using appropriate cuff size in the supine position 2
- Home or ambulatory blood pressure monitoring provides more accurate assessment than in-center measurements and should guide management decisions 2
- Predialysis and postdialysis measurements alone correlate poorly with interdialytic ambulatory blood pressure and should not be the sole basis for treatment decisions 2
Ultrafiltration Rate Management
Limit ultrafiltration rate to prevent excessive intradialytic hypotension while achieving target fluid removal, typically keeping rates below 13 mL/kg/hour. 4
- Excessive ultrafiltration rates increase intradialytic hypotension risk and are associated with increased mortality 4
- For 2.5 L removal over 6 hours, the ultrafiltration rate of 417 mL/hour is generally well-tolerated 4
- Monitor MAP every 30 minutes during sessions, particularly when initiating new ultrafiltration targets 4
Pharmacological Management When Volume Control Insufficient
If blood pressure remains elevated despite achieving dry weight, initiate ACE inhibitors or ARBs as first-line agents, administered preferentially at night to reduce nocturnal blood pressure surge. 2
- ACE inhibitors and ARBs cause greater regression of left ventricular hypertrophy and may preserve residual kidney function 2
- Beta-blockers are preferred in patients with coronary artery disease or heart failure 2
- Consider medication dialyzability when selecting agents—highly dialyzable medications like metoprolol may have reduced efficacy during dialysis periods 2
Critical Pitfalls to Avoid
Do not initiate or escalate antihypertensive medications without first assessing and optimizing volume status, as this represents the most common error in hemodialysis blood pressure management. 2
- Relying solely on predialysis or postdialysis measurements leads to inappropriate treatment decisions 2
- A U-shaped relationship exists between blood pressure and mortality in dialysis patients—excessive reduction increases mortality risk 1, 2
- Failing to account for the time-averaged fluid overload during the interdialytic period results in inadequate volume assessment 5
Sodium Management Strategy
Implement strict dietary sodium restriction (2-3 g/day) with regular dietitian counseling and consider lower dialysate sodium concentrations (135 mmol/L rather than 140 mmol/L). 2, 6
- High dialysate sodium concentration and sodium profiling aggravate thirst, fluid gain, and hypertension 2
- Sodium mass balance during hemodialysis directly impacts interdialytic fluid accumulation and blood pressure control 5
Special Populations
In elderly patients (>75 years), target MAP of 60-65 mmHg may reduce mortality compared to higher targets of 75-80 mmHg. 1