Polydipsia: a feature of peritoneal dialysis.
BACKGROUND
Some dialysis patients fail to comply with their fluid restriction causing problems due to volume overload. These patients sometimes blame excessive thirst. There has been little work in this area and no work documenting polydipsia among peritoneal dialysis (PD) patients.


METHODS
We measured motivation to drink and fluid consumption in 46 haemodialysis patients (HD), 39 PD patients and 42 healthy controls (HC) using a modified palmtop computer to collect visual analogue scores at hourly intervals.


RESULTS
Mean thirst scores were markedly depressed on the dialysis day (day 1) for HD (P<0.0001). The profile for day 2 was similar to that of HC. PD generated consistently higher scores than HD day 1 and HC (P = 0.01 vs. HC and P<0.0001 vs HD day 1). Reported mean daily water consumption was similar for HD and PD with both significantly less than HC (P<0.001 for both). However, measured fluid losses were similar for PD and HC whilst HD were lower (P<0.001 for both) suggesting that the PD group may have underestimated their fluid intake.


CONCLUSIONS
Our results indicate that HD causes a protracted period of reduced thirst but that the population's thirst perception is similar to HC on the interdialytic day despite a reduced fluid intake. In contrast, the PD group recorded high thirst scores throughout the day and were apparently less compliant with their fluid restriction. This is potentially important because the volume status of PD patients influences their survival.
Wright
Mark
M
Renal Unit, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, UK. mark.wright@leedsth.nhs.uk
Woodrow
Graham
G
O'Brien
Siobahn
S
King
Neil
N
Dye
Louise
L
Blundell
John
J
Brownjohn
Aleck
A
Turney
John
J
D000328:Adult; D000368:Aged; D004326:Drinking; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis; D006435:Renal Dialysis; D013894:Thirst / Q000502:physiology