Ultrafiltration failure in peritoneal dialysis: a pathophysiologic approach.

Area of Science:

• Nephrology
• Dialysis Technology
• Renal Medicine

Background:

• Ultrafiltration failure is a primary reason for peritoneal dialysis technique failure.
• This often necessitates a switch to hemodialysis for patients.

Purpose of the Study:

• To define ultrafiltration failure in peritoneal dialysis.
• To describe the major causes and diagnostic clues for ultrafiltration failure.

Main Methods:

• Definition: Failure to achieve ≥400 ml net ultrafiltration in a 4-hour dwell with 4.25% dextrose.
• Characterization of four major causes based on peritoneal transport and fluid dynamics.

Main Results:

• Four causes identified: high effective peritoneal surface area, low osmotic conductance to glucose, low effective peritoneal surface area, and high total peritoneal fluid loss.
• Specific diagnostic markers include D/P creatinine, sodium sieving, peritoneal free water clearance, and response to icodextrin dwells.

Conclusions:

• Recognizing the distinct pathophysiology of each ultrafiltration failure cause is crucial for accurate diagnosis.
• This knowledge aids in managing peritoneal dialysis patients and preventing technique failure.