Manual PD Bags vs. APD Machine for Fluid Overload

The Core Problem: Long Dwells and Fluid Reabsorption

Net peritoneal fluid absorption commonly occurs with long-duration dwells, such as the diurnal (daytime) dwell in APD, which directly counteracts efforts to remove excess fluid in patients with fluid overload 1, 2
The American College of Physicians guidelines are not mentioned, however the American Journal of Kidney Diseases guidelines explicitly state that particular attention should be given to net peritoneal fluid absorption during long dwells because this can be avoided by altering the PD prescription 1
In volume-overloaded or hypertensive patients, ultrafiltration should never be negative (no fluid absorption) for any exchanges, making standard APD with long day dwells problematic 3

CAPD allows for more frequent, shorter dwells (typically 4-5 exchanges per day) that prevent the fluid reabsorption seen with prolonged dwells in patients with fluid overload 4
Manual exchanges provide immediate flexibility to adjust dwell times and glucose concentrations based on real-time volume status without waiting for programmed cycles in patients with fluid overload 1
Shorter dwell times optimize ultrafiltration by preventing the equilibration that leads to fluid reabsorption, particularly important in high and high-average transporters 2, 5

APD patients often prefer "dry day" prescriptions (no daytime dwell), which severely compromises ultrafiltration capacity when volume removal is most needed in patients with fluid overload 4, 5
Even when APD includes a day dwell, the long duration (8-16 hours) allows significant fluid reabsorption, especially in high transporters 2, 5
The Kidney International guidelines note that APD with long day dwells may require shortening or elimination of the dwell to prevent fluid reabsorption, essentially converting the prescription toward a CAPD-like pattern 5

Avoiding long-duration dwells that are associated with ineffective fluid removal or net fluid resorption is recommended for patients with fluid overload 2
Using icodextrin solution for any necessary long dwells (if APD must be used) to maintain ultrafiltration, as RCTs demonstrate it increases peritoneal ultrafiltration and decreases extracellular fluid volume in patients with fluid overload 2
Implementing shorter, more frequent exchanges to maximize cumulative ultrafiltration—a pattern naturally achieved with manual CAPD—is recommended for patients with fluid overload 1, 2

Shorten or eliminate the day dwell, leaving the patient "dry" for a portion of the day, to prevent fluid reabsorption in patients with fluid overload 2, 5
Drain and replace the day dwell partway through with fresh dialysis solution to prevent reabsorption in patients with fluid overload 2
Use icodextrin exclusively for the long day dwell to maintain ultrafiltration throughout the extended dwell time in patients with fluid overload 2, 5

Do not assume APD provides superior volume control simply because it is automated—no robust data suggest APD results in better volume control than CAPD, and modality selection should prioritize ultrafiltration capacity over convenience in patients with fluid overload 5
Avoid relying on hypertonic 4.25% glucose solutions to compensate for poor APD ultrafiltration, as frequent use damages the peritoneal membrane and causes adverse metabolic effects in patients with fluid overload 5
Never ignore negative ultrafiltration (fluid absorption) in any exchange when managing volume overload, as this directly worsens the clinical condition in patients with fluid overload 3

The International Society of Nephrology recommends maximizing peritoneal ultrafiltration by optimizing the PD prescription to achieve euvolemia 6, 7
The American Society of Nephrology suggests using icodextrin solution for long dwells to increase ultrafiltration and decrease extracellular fluid volume 8, 9
The National Kidney Foundation recommends considering shortening dwell times with glucose-based solutions, especially for high transporters, to prevent fluid reabsorption 8, 6
The European Renal Association advises avoiding long-duration dwells that are associated with ineffective fluid removal or net fluid resorption 8, 9

The International Society of Peritoneal Dialysis recommends using icodextrin for the long dwell to increase peritoneal ultrafiltration and decrease extracellular fluid volume 6, 7
Randomized controlled trials have shown icodextrin increases peritoneal ultrafiltration and decreases extracellular fluid volume, as reported by the American Journal of Kidney Diseases 9
The American Society of Nephrology suggests minimizing use of hypertonic glucose solutions due to concerns about peritoneal membrane damage and adverse metabolic effects 8, 9

The National Kidney Foundation states that no definitive evidence suggests one PD modality is superior to the other for volume control; selection should consider patient-specific factors 6
The European Renal Association recommends paying close attention to sodium sieving effect in APD patients with multiple short overnight dwells, which may compromise BP control 10

The American Heart Association recommends preserving residual kidney function (RKF) as it is strongly associated with better BP control, although the exact mechanism is not specified in the provided text, high-dose loop diuretics may be used to enhance urinary sodium and water removal in patients with RKF 8, 6
The American Society of Nephrology suggests restricting dietary sodium intake if persistent hypertension and fluid overload are present 8, 11
The International Society of Nephrology recommends monitoring salt and water removal by measuring daily urinary volume/sodium content and the difference between dialysate effluent and infused dialysis solution 11, 12

The National Kidney Foundation advises assessing blood pressure and volume status monthly 11, 12
The European Renal Association recommends evaluating drain volume, residual kidney function, and dietary salt/water intake monthly 11
The American Society of Nephrology suggests paying particular attention to net peritoneal fluid absorption during long duration dwells 12