What is hemodialysis profiling?

Hemodialysis Profiling

Hemodialysis profiling refers to the systematic variation of dialysis treatment parameters during a single dialysis session, most commonly involving modulation of dialysate sodium concentration (sodium profiling) or ultrafiltration rate (ultrafiltration profiling), with the goal of reducing intradialytic symptoms and improving hemodynamic stability. 1, 2

Core Concept

Profiled hemodialysis (PHD) involves pre-programmed changes to dialysis parameters throughout the treatment session rather than maintaining constant settings. 2 The technique emerged to address intradialytic complications, particularly in high-risk patients with cardiovascular disease who experience vascular instability syndrome. 2

Types of Profiling

Sodium Profiling

• Involves continuous modulation of dialysate sodium concentration throughout the extracorporeal session to antagonize changes in intradialytic plasma osmolarity. 2
• Typically uses higher dialysate sodium concentrations in the first half of the session (when plasma osmolarity changes are greatest) to reduce the sodium removal rate, then adjusts to achieve the desired individual sodium balance by session end. 2, 3
• Mathematical algorithms can determine rational sodium profiles a priori before each session, respecting individual sodium mass removal and weight gain requirements. 3

Ultrafiltration Profiling

• Involves varying the ultrafiltration rate during the dialysis session rather than maintaining a constant rate. 4
• Often combined with sodium profiling to reduce hemodialysis-related symptoms. 4

Blood Volume Monitoring

• Uses intradialytic blood volume monitoring to guide treatment adjustments, though this approach is associated with higher mortality and hospitalization rates compared to conventional clinical monitoring. 1

Physiological Mechanism

Profiling aims to maintain more stable intradialytic blood volume and hemodynamics by reducing the rate of change in blood volume, particularly in the first half of the dialysis session. 2, 4 The technique reduces the slope of the blood volume curve during dialysis (standard: -2.96%/h versus profiled: -1.96%/h), which correlates with improved cardiovascular tolerance to ultrafiltration. 4

Clinical Evidence and Current Recommendations

Efficacy Data

• Combined sodium and ultrafiltration profiling reduces symptomatic dialysis sessions from 30.6% to 20.4% (odds ratio 0.61,95% CI 0.39-0.96). 4
• Profiling is associated with lower symptom scores during both intradialytic and interdialytic periods. 4
• The technique maintains more stable blood pressure and heart rate throughout the session compared to standard hemodialysis. 2

Critical Guideline Warnings

Despite some symptomatic benefits, current guidelines explicitly recommend AGAINST routine use of profiling techniques due to significant safety concerns. 1

• Sodium profiling is associated with increased all-cause mortality and should not be used routinely. 1
• The technique results in sodium loading, hypervolemia, increased thirst, and greater interdialytic weight gain (0.3 kg higher predialysis weight). 1, 4
• KDOQI guidelines explicitly state that increasing positive sodium balance by sodium profiling or using high dialysate sodium concentration should be avoided (Grade B recommendation). 1
• Blood volume monitoring for routine profiling is associated with higher mortality and hospitalization rates. 1

Common Pitfalls

• Do not implement routine blood volume monitoring based on older literature—the CLIMB trial demonstrated harm with this approach. 1
• Avoid routine sodium profiling given the DOPPS mortality data; reserve it only for highly selected cases with severe intradialytic hypotension unresponsive to other interventions. 1
• Recognize that interdialytic weight gain exceeding 4.8% of body weight is associated with increased mortality, and profiling techniques that promote positive sodium balance exacerbate this risk. 1
• Understand that poor volume control from positive sodium balance worsens hypertension and cardiovascular outcomes in dialysis patients. 1

Alternative Approaches

Rather than using profiling, optimize volume management through adequate ultrafiltration to achieve euvolemia, counsel patients on sodium restriction to ≤5 g sodium chloride (2.0 g or 85 mmol sodium) daily, and consider cooling dialysate temperature to 0.5°C below body temperature for hemodynamic stability. 1