What are the steps to initiate automated peritoneal dialysis (APD) in a patient with impaired renal function?

Initiating Automated Peritoneal Dialysis (APD)

To initiate automated peritoneal dialysis (APD), wait 10-14 days after catheter placement, assess residual kidney function, determine peritoneal membrane transport characteristics, and start with a prescription of 2.0-3.0L exchanges based on body surface area with 9-10 hours of overnight cycling plus a daytime dwell. 1, 2

Pre-Initiation Assessment

1. Catheter placement and timing:

   • Wait 10-14 days after peritoneal catheter placement before starting regular APD 1
   • If urgent dialysis is needed sooner, use low-volume, supine dialysis to minimize leakage risk 1

2. Baseline assessments:

   • Obtain 24-hour urine collection for urea and creatinine clearance 1
   • Document patient's weight and presence/absence of edema 1
   • Determine peritoneal membrane transport characteristics after 4-8 weeks of starting dialysis 1

Initial APD Prescription Setup

1. Select appropriate fill volumes based on BSA: 2

   • BSA < 1.7 m²: 2.0L exchanges
   • BSA 1.7-2.0 m²: 2.5L exchanges
   • BSA > 2.0 m²: 3.0L exchanges
   • For children: Use BSA-normalized volumes (at least 1,100 mL/m²)

2. Configure cycler settings: 2, 3

   • Total treatment time: 9-10 hours overnight
   • Initial cycles: 4-5 cycles per night
   • Dwell time: Approximately 2 hours per cycle
   • Total overnight volume: 10-15L
   • Monitor intraperitoneal pressure (keep below 18 cmH2O)

3. Daytime component: 2

   • Include 1-2 daytime dwells (2.0-3.0L) for most patients
   • Approximately 85% of APD patients will need daytime dwells 1
   • Consider icodextrin for the long daytime dwell in patients with high transport characteristics or volume issues 2

Adjusting Based on Residual Kidney Function (RKF)

1. For patients with significant RKF (eGFR ≥ 2 mL/min): 2

   • Consider night intermittent peritoneal dialysis (NIPD) without daytime dwell
   • Use 2.5-3.0L overnight exchanges (9-10 hours)

2. For patients with minimal RKF (eGFR < 2 mL/min): 2, 3

   • Use continuous cycling peritoneal dialysis (CCPD) with daytime dwell
   • 2.0-3.0L overnight exchanges (9 hours) plus 2.0-3.0L daytime dwell
   • Anuric patients usually require 15-20L total fill volume

Monitoring and Adjustment

1. Target clearance goals: 3

   • Weekly total Kt/V urea ≥ 1.7
   • For low peritoneal transporters: weekly total creatinine clearance ≥ 45 L/1.73 m²

2. Volume status monitoring: 2

   • Monitor drain volumes monthly
   • Ensure positive ultrafiltration for all exchanges in hypertensive or volume-overloaded patients
   • Adjust dextrose concentration as needed for volume control

3. Peritonitis diagnosis in APD patients: 3

   • For suspected peritonitis, infuse 1L of dialysate and permit to dwell for 2 hours before analysis
   • Differential white cell count may be more useful than total cell counts

Special Considerations

1. Transport characteristics: 2

   • High transporters: Benefit most from APD with shorter dwell times
   • Low transporters: May need longer dwell times to achieve adequate clearance

2. Volume management challenges: 1

   • Be aware of sodium sieving effect with short overnight cycles
   • Consider using fewer than 4 exchanges during 8 hours
   • Consider midday exchange or "dry time" if volume control is problematic
   • Icodextrin may help with ultrafiltration during long dwells

3. Medication adjustments: 4

   • Increased elimination of antibiotics during cycler therapy must be considered for patients with peritonitis

By following these steps and making appropriate adjustments based on individual patient characteristics, APD can provide effective dialysis while potentially offering better quality of life and flexibility for patients compared to CAPD 4.