Abstract: FR-PO764
Changes in Serum Magnesium During Hemodialysis in Three Facility Settings
Session Information
- Dialysis: Inflammation and Infection
October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 701 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Lacson, Eduardo K., Tufts University School of Medicine, Boston, Massachusetts, United States
- Aweh, Gideon N., Dialysis Clinic, Inc., Nashville, Tennessee, United States
- Bergeaux, Dwayne J., DCI, Crowley, Louisiana, United States
- Fontenot, Deana, Dialysis Clinic Inc., Nashville, Tennessee, United States
- Putatunda, Bhabendra, Nephrology Associates PC, Murfreesboro, Tennessee, United States
- Wadhwa, Nand K., Stony Brook Medicine, Stony Brook, NY, East Setauket, New York, United States
Background
A quality improvement project monitored serial serum magnesium (sMg) after a manufacturer changed dialysate magnesium (dMg) content. Three Medical Directors decided to order facility-wide post-dialysis sMg in addition to pre-dialysis sMg. Only 60-75% of sMg diffuse during hemodialysis (HD) due to sequestration by albumin a.k.a. the Gibbs-Donnan effect.
Methods
All maintenance HD patients in three outpatient units were included and sMg were tested with the monthly blood draws for December, 2017. Facility A utilized a dMg of 1.0 mEq/L which is most commonly used by DCI, a non-profit dialysis provider. Facility B also utilized dMg of 1.0 mEq/L but routinely gave oral magnesium supplements to target pre-dialysis sMg of ~2.0 mEq/L. Facility C utilized a dMg of 1.6 mEq/L with a citrate-based bath for over three years.
Results
The facilities (A-B-C) had varying levels of pre-dialysis sMg with A having levels consistent with other DCI facilities at ~1.8 mEq/L.; B had higher pre-dialysis sMg of ~2.0 mEq/L consistent with its target; and C also had elevated pre-dialysis sMg consistent with prior reports at dMg ~1.5 mEq/L. At dMg = 1.0 mEq/L A (representing usual care) had ~10% decline of sMg post-dialysis compared to ~17% decline in B, which started with higher pre-dialysis sMg. The sMg was unchanged in C with no net removal at dMg of 1.6 mEq/L. Results are summarized in the table.
Conclusion
Serum magnesium did not fully equilibrate with dialysate consistent with the Gibbs-Donnan effect. Net sMg removal increases with higher sMg levels at dMg of 1.0 mEq/L; At dMg of 1.6 mEq/L, sMg is maintained at ~2.1 to 2.2 mEq/L with no net dialytic magnesium removal. These findings illustrate what could be expected in a comparative effectiveness study comparing dMg at 1.0 vs. 1.5 mEq/L.
Pre- & Post-HD Magnesium Under 3 Different Settings
| Facility | Dialysate Mg | Oral Mg Supplement | N | Pre-HD Mg | Post-HD Mg | % Change |
| A | 1.0 mEq/L | No | 52 | 1.79 ± 0.25 | 1.61 ± 0.10 | -10% |
| B | 1.0 mEq/L | Yes | 131 | 2.07 ± 0.27 | 1.71 ± 0.12 | -17% |
| C | 1.6 mEq/L | No | 42 | 2.15 ± 0.31 | 2.15 ± 0.19 | 0% |
Mg = Magnesium; Note: Pre-HD & Post-HD serum magnesium shown as mean +/- standard deviation, in mEq/L.