From the Guidelines
Planning a dialysis prescription for a patient with impaired renal function requires careful consideration of several key factors, and the prescription should be individualized based on the patient's residual kidney function, body size, metabolic needs, and cardiovascular stability, with a goal to achieve a minimum Kt/V of 1.2 per session or weekly Kt/V of 3.6, as recommended by the National Kidney Foundation 1.
Key Factors to Consider
- Residual kidney function
- Body size
- Metabolic needs
- Cardiovascular stability
Hemodialysis Prescription
- Three sessions per week, each lasting 3-4 hours, with a blood flow rate of 300-400 mL/min and a dialysate flow rate of 500-800 mL/min, as suggested by the kdoqi clinical practice guideline for hemodialysis adequacy: 2015 update 1
- Dialyzer selection based on patient's body size and clearance needs, typically starting with a mid-efficiency dialyzer
Peritoneal Dialysis Prescription
- Options include continuous ambulatory peritoneal dialysis (CAPD) with 4 exchanges daily using 2-2.5L volumes, or automated peritoneal dialysis (APD) with 8-10L overnight plus potentially a daytime dwell, as outlined in the nkf-k/doqi clinical practice guidelines for peritoneal dialysis adequacy: update 2000 1
- Initial dialysis prescription can be empirically based on patient's weight, amount of residual kidney function, and lifestyle constraints
Ultrafiltration and Dialysate Composition
- Ultrafiltration goals should be set to achieve dry weight without causing hemodynamic instability, typically removing 2-3L per session for hemodialysis
- Dialysate composition should be tailored to the patient's electrolyte needs, with potassium typically ranging from 0-4 mEq/L, calcium 2.5-3.5 mEq/L, and sodium 135-145 mEq/L
Monitoring and Adjustment
- Regular monitoring of pre- and post-dialysis blood urea nitrogen, creatinine, electrolytes, and clinical parameters is essential to assess adequacy and adjust the prescription accordingly, as recommended by the clinical practice recommendations for peritoneal dialysis adequacy 1
From the Research
Guidelines for Planning a Dialysis Prescription
To plan a dialysis prescription for a patient with impaired renal function, several factors must be considered.
- The total quantity of urea clearance to be administered, which is essential to assure optimum outcomes for dialysis patients 2.
- The description of the dialysis variables required to deliver the prescribed treatment, including the blood flow rate, the dialyzer to be used, and the dialysate flow rate 2.
- The assessment of the patient's fluid status, as both fluid overload and depletion can be associated with increased mortality risk 3.
- The use of erythropoietin (EPO) to manage anemia, which may require different dosages for patients on peritoneal dialysis (PD) and hemodialysis (HD) 4, 5, 6.
Considerations for Hemodialysis and Peritoneal Dialysis
- Hemodialysis patients may require higher EPO doses and more frequent administration than peritoneal dialysis patients to achieve the same hemoglobin levels 6.
- Peritoneal dialysis patients may have better removal of inhibitors of erythropoiesis, which could contribute to the reduced EPO requirements 5, 6.
- The route of EPO administration, such as subcutaneous or intravenous, may also impact the effectiveness of the treatment 6.
Assessment and Monitoring
- Regular assessment of the patient's fluid status, using techniques such as bioimpedance, lung ultrasound, or biochemical markers, is crucial to guide dialysis management 3.
- Monitoring of hemoglobin levels, ferritin, and transferrin saturation index can help adjust EPO dosages and iron supplementation as needed 6.