Polydipsia: a feature of peritoneal dialysis

Area of Science:

• Nephrology
• Clinical Medicine
• Patient Monitoring

Background:

• Fluid overload and non-compliance with fluid restrictions are common issues in dialysis patients.
• Excessive thirst (polydipsia) is often cited by patients but lacks thorough investigation, especially in peritoneal dialysis (PD) patients.

Purpose of the Study:

• To investigate and compare thirst perception and fluid consumption in hemodialysis (HD) and PD patients against healthy controls (HC).
• To understand the relationship between thirst, fluid intake, and compliance in different renal replacement therapy modalities.

Main Methods:

• Utilized a modified palmtop computer for hourly visual analogue scale (VAS) scoring of thirst motivation.
• Measured fluid consumption and fluid losses in 46 HD patients, 39 PD patients, and 42 HC over a defined period.

Main Results:

• Hemodialysis (HD) patients exhibited significantly reduced thirst scores on dialysis days compared to healthy controls (HC).
• Peritoneal dialysis (PD) patients reported consistently higher thirst scores than both HD patients and HC.
• While reported water intake was lower in both dialysis groups compared to HC, PD patients showed higher thirst, suggesting potential underestimation of fluid intake and non-compliance.

Conclusions:

• Hemodialysis induces a prolonged period of decreased thirst, with interdialytic thirst perception normalizing but fluid intake remaining reduced.
• Peritoneal dialysis patients experience elevated thirst throughout the day and may be less compliant with fluid restrictions, posing a risk to their volume status and survival.