Determinants of phosphorus mobilization during hemodialysis

Leypoldt, John K.; Agar, Baris U.; Akonur, Alp; Hutchcraft, Audrey; Story, Kenneth; Culleton, Bruce F.

doi:10.1038/ki.2013.205

Cited by 22 publications

(34 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Positive univariate associations were found for both potassium mobilization clearance and predialysis central distribution volume with predialysis body weight; both of these kinetic parameters can be expected to be larger for patients with larger body weight, similar to that previously reported for phosphorus . The negative univariate associations of these kinetic parameters with predialysis serum potassium concentration are also similar to those previously reported for phosphorus .…”

Section: Discussionsupporting

confidence: 87%

“…This is expected since potassium is a smaller electrolyte than phosphate and therefore might be more rapidly mobilized by differences in concentration induced by rapid solute removal during hemodialysis. The potassium central distribution volume is comparable to, but somewhat larger than, that previously determined for phosphorus . These findings suggest that both potassium and phosphorus have a kinetically determined central distribution volume that is comparable in size to the extracellular volume.…”

Section: Discussionsupporting

confidence: 69%

“…Potassium is not uniformly distributed in body fluids; about 2% of total body potassium is contained within the extracellular compartment, the remaining 98% is largely intracellular . Such a distribution of body potassium suggests that its kinetics can be approximated by using a pseudo one‐compartment model where potassium is removed during hemodialysis from a central compartment that is much smaller than an inaccessible, peripheral compartment, analogous to that previously demonstrated for inorganic phosphorus . The assumption of a very large inaccessible compartment requires that the potassium concentration in that compartment remains approximately constant; indeed, several previous studies have reported that the intracellular potassium concentration within red blood cells is only slightly (<4%) reduced by the end of a hemodialysis treatment, if at all .…”

Section: Discussionmentioning

confidence: 90%

See 2 more Smart Citations

Potassium kinetics during hemodialysis

Agar

Culleton

Fluck

et al. 2014

Hemodialysis International

Self Cite

View full text Add to dashboard Cite

Hyperkalemia in hemodialysis patients is associated with high mortality, but prescription of low dialysate potassium concentrations to decrease serum potassium levels is associated with a high incidence of sudden cardiac arrest or sudden death. Improved clinical outcomes for these patients may be possible if rapid and substantial intradialysis decreases in serum potassium concentration can be avoided while maintaining adequate potassium removal. Data from kinetic modeling sessions during the HEMO Study of the dependence of serum potassium concentration on time during hemodialysis treatments and 30 minutes postdialysis were evaluated using a pseudo one-compartment model. Kinetic estimates of potassium mobilization clearance (K(M)) and predialysis central distribution volume (V(pre)) were determined in 551 hemodialysis patients. The studied patients were 58.8 ± 14.4 years of age with predialysis body weight of 72.1 ± 15.1 kg; 306 (55.4%) of the patients were female and 337 (61.2%) were black. K(M) and V(pre) for all patients were non-normally distributed with values of 158 (111, 235) (median [interquartile range]) mL/min and 15.6 (11.4, 22.8) L, respectively. K(M) was independent of dialysate potassium concentration (P > 0.2), but V(pre) was lower at higher dialysate potassium concentration (R = -0.188, P < 0.001). For patients with dialysate potassium concentration between 1.6 and 2.5 mEq/L (N = 437), multiple linear regression of K(M) and V(pre) demonstrated positive association with predialysis body weight and negative association with predialysis serum potassium concentration. Potassium kinetics during hemodialysis can be described using a pseudo one-compartment model.

show abstract

Section: Discussionsupporting

confidence: 87%

Section: Discussionsupporting

confidence: 69%

Section: Discussionmentioning

confidence: 90%

See 1 more Smart Citation

Potassium kinetics during hemodialysis

Agar

Culleton

Fluck

et al. 2014

Hemodialysis International

Self Cite

View full text Add to dashboard Cite

show abstract

“…In our study, we explored if mobilizable phosphate could be estimated using a “pseudo one‐compartmental model” ,31 : our formula integrates the dialyzer's performance (K D ) and phosphate “refilling” in patients, and was validated in a cohort of hemodialyzed patients . During our study, K M was higher during LBD than HBD (respectively, 82.94 ± 38.00 vs. 69.74 ± 24.48 mL/min, P < 0.05).…”

Section: Discussionmentioning

confidence: 99%

Modifications to bicarbonate conductivity: A way to increase phosphate removal during hemodialysis? Proof of concept

Bertocchio¹,

Mohajer²,

Gaha³

et al. 2016

Hemodialysis International

View full text Add to dashboard Cite

Introduction Hyperphosphatemia and cardiovascular mortality are associated particularly with end-stage renal disease. Available therapeutic strategies (i.e., diet restriction, calcium [or not]-based phosphate binders, calcimimetics) are associated with extrarenal blood purification. Compartmentalization of phosphate limits its depuration during hemodialysis. Several studies suggest that plasmatic pH is involved in the mobilization of phosphate from intracellular to extracellular compartments. Consequently, the efficiency of modified bicarbonate conductivity to purify blood phosphate was tested. Methods Ten hemodialysis patients with chronic hyperphosphatemia (>2.1 mmol/L) were included in the two three-sessions-per week periods. Bicarbonate concentration was fixed at 40 mmol/L and 30 mmol/L in the first and second periods, respectively. Phosphate depuration was evaluated by phosphate mobilization clearance (K ). Findings Although bicarbonatemia was lower during the second period (21.0 ± 2.7 vs. 24.4 ± 3.1 mmol/L, P < 0.01), no difference was observed in phosphatemia (2.4 ± 0.5 vs. 2.3 ± 0.4 mmol/L, P = NS). The in-session variation of phosphate was lower (-1.45 ± 0.42 vs. -1.58 ± 0.44 mmol/L, P < 0.05) and K was higher during the second period (82.94 ± 38.00 vs. 69.74 ± 24.48 mL/min, P < 0.05). Discussion The decrease of in-session phosphate and the increase in K reflect phosphate refilling during hemodialysis. Thus, modulation of serum bicarbonate may play a role in controlling the phosphate pool. Even though correcting metabolic acidosis during hemodialysis remains important, alkaline excess can impair phosphate mobilization clearance. Clinical trials are needed to test the efficiency and relevance of a strategy where bicarbonatemia is corrected less at the beginning of sessions.

show abstract

“…Phosphorus removal during HD requires its shift out of a “central compartment” to the blood. Data from a detailed analysis of HEMO study data found that phosphorus mobilization is much lower in women than in men (Km 77 vs. 99); this suggests significant gender differences in dialytic phosphorus clearance .…”

mentioning

confidence: 99%

Briefly Noted

Sherman¹

2014

Seminars in Dialysis

View full text Add to dashboard Cite

Determinants of phosphorus mobilization during hemodialysis

Cited by 22 publications

References 33 publications

Potassium kinetics during hemodialysis

Potassium kinetics during hemodialysis

Modifications to bicarbonate conductivity: A way to increase phosphate removal during hemodialysis? Proof of concept

Briefly Noted

Contact Info

Product

Resources

About