ASN's Mission

To create a world without kidney diseases, the ASN Alliance for Kidney Health elevates care by educating and informing, driving breakthroughs and innovation, and advocating for policies that create transformative changes in kidney medicine throughout the world.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: TH-PO165

Phosphate Removal During Conventional Hemodialysis Is Continuous and Depends on Pre-Dialysis Serum Levels and Bone Remodeling

Session Information

  • CKD-MBD: Targets and Outcomes
    November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
    Abstract Time: 10:00 AM - 12:00 PM

Category: Bone and Mineral Metabolism

  • 402 Bone and Mineral Metabolism: Clinical

Authors

  • Lima, Carolina Marquez, Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
  • Goldenstein, Patricia T., Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
  • dos Reis, Luciene, Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
  • Jorgetti, Vanda, Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
  • Elias, Rosilene M., Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
  • Moyses, Rosa M.A., Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
Background

Removal of phosphate (P) in conventional hemodialysis (HD) remains a cornerstone for CKD-MBD management. There is a disseminated belief that P removal after the first 90 minutes of HD is irrelevant. In addition, the main determinants of an intradialytic P balance are still a matter of debate.

Methods

We measured serum and dialysate P each 30 minduring a HDsession in 10 patients with severe hyperparathyroidism in 3 different periods: before parathyroidectomy (Pre-PTX), during hungry bone syndrome (HBS), and after stabilization of clinical status (Late-PTX). In each period, all patientswere dialyzed 3 times, using a d[Ca] of 1.25, 1.5 or1.75 mmol/L.

Results

P removalwas higher in Pre-PTXthan in HBS and Late-PTX (1098± 313 vs. 744 ±195 and 842 ± 348 mg, respectively, p = 0.04), with no difference among d[Ca]. P removal correlated with pre-dialysis serum P (r = 0.421, p =0.0001) and ultrafiltrationvolume (UF; r=0.259, p =0.014). Percentual serum P reduction in 90 minutes was 52.0%. From this point forward there was no significant change during HD. P removal in 90 minutes was 45.9%. However, despite serum P stabilization, after this point there was a continuous efflux of P, in any study period or d[Ca], of at least 10% every 30 minutes (Figure). GLM revealed that P removal was dependent,in order of importance, on the pre-dialysisserum P, UF and bone remodeling, explaining together 66.8% of P removal.

Conclusion

P removal during conventional HD is higher during the first 90 of therapy, achieving a smaller, but stable flux until the 240 minutes. An intradialytic negative P balance depends not only on the pre-dialysis serum P and UF but also on bone remodeling, which may change the P disposal on the bone surface.

Left: serum P variation during dialysis
Right: P efflux during dialysis

Funding

  • Government Support – Non-U.S.