What is a suitable peritoneal dialysis order for a patient with impaired renal function and potential hypertension?

Peritoneal Dialysis Order for Impaired Renal Function with Hypertension

For a patient with impaired renal function and potential hypertension, initiate peritoneal dialysis with a prescription targeting weekly Kt/V ≥1.7, using 4 exchanges daily of 2.0-2.5L (based on body surface area), incorporating icodextrin for the long dwell to optimize ultrafiltration and blood pressure control while minimizing glucose exposure. 1

Initial Prescription Components

Exchange Volume and Frequency

• Start with 4 exchanges per day using fill volumes of 2.0-2.5L based on patient's body surface area (BSA): 1
  • BSA <1.7 m²: 2.0L per exchange 2
  • BSA 1.7-2.0 m²: 2.5L per exchange 2
  • BSA >2.0 m²: up to 3.0L per exchange 2
• Increase fill volume before increasing number of exchanges to optimize clearance and minimize cost 1
• Target instilled volume range of 1,000-1,200 mL/m² BSA (maximum 1,400 mL/m²) 1

Solution Selection for Hypertension Management

• Use icodextrin 7.5% for the long dwell (overnight for CAPD or daytime for APD) to enhance ultrafiltration without glucose exposure 1, 3, 4
• Use lowest possible dextrose concentration in remaining exchanges to achieve target ultrafiltration 1
• Start with 1.5% dextrose solutions for short dwells, escalating to 2.5% or 4.25% only if ultrafiltration inadequate 1
• Avoid frequent use of 4.25% solutions as they are deleterious to peritoneal membrane health 1

Modality Selection

• Continuous Ambulatory PD (CAPD): 4 exchanges of 2.0-2.5L daily with 4-6 hour dwell times 1
• Automated PD (APD): Nightly cycler with 9-10 hours treatment PLUS at least one mandatory daytime dwell (required in ~85% of patients with minimal residual function) 1, 2
• No superiority of CAPD vs APD for volume control; base choice on patient preference and lifestyle 1

Volume and Blood Pressure Management Strategy

Ultrafiltration Targets

• Ensure positive ultrafiltration for all exchanges in hypertensive patients or those with volume overload 1
• Target minimum 1L daily net ultrafiltration 4
• Optimize drain volume after overnight dwell (CAPD) or daytime dwell (APD) to maximize clearance and ultrafiltration 1

Adjunctive Measures for Hypertension

• If residual kidney function present, use diuretics preferentially over increasing dialysate dextrose to achieve euvolemia 1
• Implement dietary sodium restriction (patient unable to maintain normotension with dialysis alone) 1
• Preserve residual kidney function aggressively as it strongly correlates with better survival and volume control 1, 5

Residual Kidney Function Considerations

Assessment and Preservation

• Measure 24-hour urine collection for creatinine and urea clearance at baseline before starting PD 1
• Avoid nephrotoxic agents, especially aminoglycosides 1
• Avoid hypotension and other "pre-kidney" and "post-kidney" insults 1
• Monitor residual function monthly as it has major impact on ability to achieve adequacy targets 5

Incremental Prescription Based on Residual Function

• If residual Kt/V ≥1.5/week, consider starting with only 1-2 exchanges daily (incremental PD) 1, 6
• If anuric or residual function <2 mL/min, full prescription (4 exchanges) required immediately to achieve weekly Kt/V 2.0 from peritoneal clearance alone 2, 4
• As residual function declines, progressively increase dialysate volume and/or exchange frequency 6, 4

Adequacy Monitoring and Targets

Clearance Goals

• Target total weekly Kt/V ≥1.7 (combined peritoneal + residual renal clearance) 1, 7
• Target weekly creatinine clearance ≥60L/1.73m² 1
• Measure delivered Kt/V and creatinine clearance within first month using 24-hour dialysate and urine collections 1, 7, 2

Peritoneal Equilibration Test (PET)

• Perform PET at 4 weeks to characterize membrane transport status and optimize prescription 1, 2
• Use standardized volume of 1,000-1,100 mL/m² BSA for pediatric patients; 2.0-2.5L for adults 1
• High/rapid transporters derive greatest ultrafiltration benefit from icodextrin and may require APD over CAPD 1, 4
• Low transporters require greater 24-hour solution volumes when residual function <2 mL/min 4

Ongoing Monitoring

• Monthly review of: drain volumes, ultrafiltration adequacy, blood pressure trends, weight, edema, and adherence 1, 8
• Measure adequacy every 4-6 months or when clinical changes occur (peritonitis, declining residual function) 1

Critical Pitfalls to Avoid

Prescription Errors

• Do not assume nighttime-only APD will suffice—approximately 85% of patients with minimal residual function require daytime dwells to reach Kt/V targets 1, 2
• Do not increase exchange number before maximizing fill volume—this increases cost without optimizing clearance 1
• Do not use PET results alone to guide prescription—correlation between solute transport and ultrafiltration capacity is poor 1

Volume Management Errors

• Do not overlook dietary sodium and fluid intake when ultrafiltration inadequate—evaluate these before escalating to 4.25% solutions 1
• Do not confuse poor drainage from catheter malposition with membrane transport issues—verify catheter function first 2
• Do not delay prescription adjustment if Kt/V <1.7—inadequate dialysis increases mortality, malnutrition, and uremic symptoms 7, 2, 8

Nephrotoxin Exposure

• Absolutely avoid aminoglycosides due to nephrotoxicity, ototoxicity, and vestibular toxicity risks 1
• Avoid all nephrotoxic insults to preserve residual kidney function 1

Quality of Life Considerations

• Incorporate patient's work/school schedule and lifestyle preferences when designing prescription 1
• Consider APD for patients requiring daytime freedom, but ensure adequate daytime dwell(s) included 1
• Balance clearance optimization with treatment burden—icodextrin use reduces need for midday exchanges 4
• Monitor for uremic symptoms (nausea, vomiting, appetite suppression, encephalopathy) and adjust prescription accordingly 7

Sample Order Template

Peritoneal Dialysis Order:

• Modality: CAPD (or APD with daytime dwell)
• Exchange volume: 2.0-2.5L based on BSA
• Frequency: 4 exchanges daily
• Dwell times: 4-6 hours for CAPD; 9-10 hours nightly + 1 daytime dwell for APD
• Solutions:
  • Long dwell: Icodextrin 7.5% (2.0-2.5L)
  • Short dwells: 1.5% dextrose (2.0-2.5L each), escalate concentration only if UF inadequate
• Target UF: ≥1L daily net
• Monitoring: 24-hour dialysate/urine collection at 2-4 weeks for Kt/V and creatinine clearance; PET at 4 weeks
• Adjuncts: Diuretics if residual function present; dietary sodium restriction
• Avoid: Aminoglycosides and nephrotoxins