What are the recommended Blood Flow Rate (BFR) and Dialysate Flow Rate (DFR) for heart failure patients undergoing hemodialysis?

Blood Flow Rate and Dialysate Flow Rate for Heart Failure Patients on Hemodialysis

For heart failure patients on hemodialysis, target a blood flow rate of 300-400 mL/min (preferably 400 mL/min when hemodynamically tolerated) and a dialysate flow rate of 700-800 mL/min, while keeping ultrafiltration rates below 10 mL/h/kg to minimize cardiovascular mortality risk. 1, 2

Blood Flow Rate (BFR) Recommendations

Target Range and Rationale

• Aim for 400 mL/min when the patient can tolerate it hemodynamically, as higher BFRs are associated with better blood pressure stability during dialysis in heart failure patients 1
• Never allow BFR to fall below 300 mL/min, as this is the absolute minimum required to achieve adequate dialysis dose (spKt/V ≥1.2) 1, 2
• BFR below 300 mL/min extends treatment times and results in underdialysis due to unrecognized recirculation, occurring in approximately 15% of catheter treatments 3, 2
• Research demonstrates that BFR <250 mL/min is associated with 66% higher all-cause mortality (HR 1.66,95% CI 1.00-2.73) 4

Monitoring Requirements

• Monitor prepump arterial pressure continuously - BFR adequacy must be qualified by prepump arterial pressure, not just the pump setting 1, 3
• Check intradialytic blood pressure every 30 minutes 1
• Adjust ultrafiltration rate if systolic blood pressure drops >30 mmHg or mean arterial pressure falls <65 mmHg 1

Dialysate Flow Rate (DFR) Recommendations

Standard Settings

• Set dialysate flow rate at 700-800 mL/min for conventional thrice-weekly hemodialysis in heart failure patients 1
• The acceptable range is 500-800 mL/min, but higher rates within this range optimize small solute clearance 1
• The FHN Daily Trial used mean DFR of 747 ± 68 mL/min for frequent hemodialysis and 710 ± 106 mL/min for conventional hemodialysis, demonstrating improved outcomes in cardiovascular disease patients 1

Critical Ultrafiltration Rate Management

The Most Important Parameter for Heart Failure Patients

• Keep ultrafiltration rates below 10 mL/h/kg to minimize cardiovascular mortality risk 1
• This often requires longer or more frequent dialysis sessions to achieve adequate fluid removal 1
• Extended treatment time allows adequate fluid removal at moderate ultrafiltration rates, reducing risk of intradialytic hypotension and end-organ ischemia 1

Hemodynamic Considerations

• Heart failure patients are particularly vulnerable to rapid volume shifts 5
• Patients with cardiac failure (NYHA III-IV) show more pronounced systolic blood pressure decreases at higher ultrafiltration rates during combined ultrafiltration and hemodialysis compared to isolated ultrafiltration 5
• Peritoneal dialysis or more frequent/longer duration hemodialysis may be better tolerated due to slower ultrafiltration rates, leading to less intradialytic hypotension 6

Treatment Time Adjustments

Minimum Duration

• Prescribe a bare minimum of 3 hours per session for patients with low residual kidney function (<2 mL/min) undergoing thrice-weekly hemodialysis 3
• Consider longer treatment times or additional sessions for heart failure patients with large weight gains, high ultrafiltration rates, poorly controlled blood pressure, or difficulty achieving dry weight 3

Common Pitfalls and How to Avoid Them

Access-Related Issues

• Do not wait until BFR decreases to 300 mL/min before intervening - this may be too late to prevent catheter thrombosis and access site loss 2
• Modern catheters are capable of achieving 400 mL/min or greater when properly placed 2
• Catheter dysfunction leads to 17-33% of untimely catheter removals 3

Monitoring Errors

• Never rely on BFR alone without monitoring prepump arterial pressure - this can lead to false reassurance about dialysis adequacy 2
• Inadequate blood sampling techniques can lead to inaccurate Kt/V calculations 1
• Ignoring treatment time reductions due to late starts or early terminations affects dialysis efficacy 1

Volume Management Errors

• Avoid aggressive ultrafiltration on first sessions without assessing hemodynamic tolerance 1
• Do not ignore intradialytic symptoms (cramping, nausea, dizziness) - these indicate the ultrafiltration rate may be too aggressive 1
• Excessive saline boluses defeat the purpose of fluid removal 1

Special Considerations for Heart Failure Patients

Dialysis Modality Options

• Consider peritoneal dialysis as an alternative, which may decrease hospitalization days and lead to symptomatic improvement in heart failure patients 3
• Peritoneal dialysis offers smaller hemodynamic shifts and lacks need for venous catheters 3
• More frequent or longer duration hemodialysis sessions may be better tolerated 6

Cardiovascular Monitoring

• Heart failure with preserved ejection fraction (HFpEF) is the most common phenotype in dialysis patients (35% of all patients, 61% of heart failure cases) 7
• Hemodialysis-related hypotension may accelerate loss of residual kidney function 2
• Maintain euvolemia as a cornerstone of heart failure treatment in dialysis patients 3