The effect of dialysis modality on phosphate control : haemodialysis compared to haemodiafiltration. The Pan Thames Renal Audit.
OBJECTIVE
Hyperphosphataemia is a primary risk factor for patients with end-stage kidney failure. Phosphate clearance by traditional thrice-weekly standard haemodialysis is inadequate for patients achieving recommended dietary protein goals. We investigated whether phosphate control was improved by adding convective clearance with haemodiafiltration.


METHODS
We audited pre-midweek session calcium and phosphate levels in 5366 adult patients, 4515 treated by haemodialysis and 851 by on-line haemodiafiltration.


RESULTS
The cohorts were similar for age, sex and dialysis vintage. Serum phosphate was lower in the haemodiafiltration cohort (1.42 +/- 0.61 mmol/l) compared to the haemodialysis cohort (1.53 +/- 0.53 mmol/l; P < 0.001), as was the calcium-phosphate product (3.31 +/- 1.53 vs 3.5 +/- 1.33 mmol(2)/l(2), respectively; P < 0.001) despite a shorter treatment session time (3.68 +/- 0.44 vs 3.92 +/- 0.49 h; P < 0.001). Parathyroid hormone levels were similar.


CONCLUSIONS
The results of this audit suggest that haemodiafiltration offers improved phosphate control compared to standard intermittent haemodialysis.
Davenport
Andrew
A
UCL Centre for Nephrology, Royal Free Campus, University College London Medical School London, UK. andrew.davenport@royalfree.nhs.uk
Gardner
Carrie
C
Delaney
Michael
M
D000368:Aged; D002118:Calcium / Q000097:blood; D054869:Clinical Audit; D005260:Female; D017583:Hemodiafiltration; D006801:Humans; D054559:Hyperphosphatemia / Q000453:epidemiology; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010710:Phosphates / Q000097:blood*; D011446:Prospective Studies; D006435:Renal Dialysis; D012307:Risk Factors; D016896:Treatment Outcome
D010281:Parathyroid Hormone; D010710:Phosphates; D002118:Calcium