Audit of the effect of dialysate sodium concentration on inter-dialytic weight gains and blood pressure control in chronic haemodialysis patients.
OBJECTIVE
Over the last three decades the standard dialysate sodium concentration has increased from 136 to 140 mmol/l (mEq/l) today. There has been great debate as to whether a reduction in dialysate sodium alone can lead to improved blood pressure control, and reduced inter-dialytic weight gain.


METHODS
An audit was performed in 469 maintenance regular haemodialysis patients who dialysed in seven different centres under the care of one university medical school.


RESULTS
Those centres which predominantly used a dialysate sodium of 140 mmol/l (mEq/l) had increased inter-dialytic weight gains, with more difficult blood pressure control, as not only did a greater percentage of patients require anti-hypertensive medication, but also more were prescribed multiple classes of anti-hypertensive agents. There was no difference in the frequency of symptomatic intra-dialytic hypotension.


CONCLUSIONS
A reduction in dialysate sodium was associated with lower inter-dialytic weight gains, without any additional intra-dialytic hypotensive episodes. Those patients in whom the difference between the time-averaged dialysate sodium concentration and the midweek pre-dialysis serum sodium was positive result had increased inter-dialytic weight gains, compared to those with a negative value. Reduced dialysate sodium alone was not effective in controlling blood pressure without additional proper dietary sodium restriction.
Davenport
Andrew
A
Consultant Renal Physician/Honorary Senior Lecturer, Royal Free and University College Hospital Medical School, Centre for Nephrology, Royal Free Hospital, London, UK. Andrew.Davenport@royalfree.nhs.uk
D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D015312:Hemodialysis Solutions / Q000737:chemistry* / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D009994:Osmolar Concentration; D006435:Renal Dialysis; D012964:Sodium / Q000032:analysis*; D013997:Time Factors; D015430:Weight Gain
D000959:Antihypertensive Agents; D015312:Hemodialysis Solutions; D012964:Sodium