Model-based analysis of potassium removal during hemodialysis.
Artif Organs
; 33(10): 835-43, 2009 Oct.
Article
em En
| MEDLINE
| ID: mdl-19681843
ABSTRACT
Potassium ion (K(+)) kinetics in intra- and extracellular compartments during dialysis was studied by means of a double-pool computer model, which included potassium-dependent active transport (Na-K-ATPase pump) in 38 patients undergoing chronic hemodialysis. Each patient was treated for 2 weeks with a constant K(+) dialysate concentration (K(+)(CONST) therapy) and afterward for 2 weeks with a time-varying (profiled) K(+) dialysate concentration (K(+)(PROF) therapy). The two therapies induced different levels of K(+) plasma concentration (K(+)(CONST) 3.71 +/- 0.88 mmol/L vs. K(+)(PROF) 3.97 +/- 0.64 mmol/L, time-averaged values, P < 0.01). The computer model was tuned to accurately fit plasmatic K(+) measured in the course and 1 h after K(+)(CONST) and K(+)(PROF) therapies and was then used to simulate the kinetics of intra- and extracellular K(+). Model-based analysis showed that almost all the K(+) removal in the first 90 min of dialysis was derived from the extracellular compartment. The different K(+) time course in the dialysate and the consequently different Na-K pump activity resulted in a different sharing of removed potassium mass at the end of dialysis 56% +/- 17% from the extracellular compartment in K(+)(PROF) versus 41% +/- 14% in K(+)(CONST). At the end of both therapies, the K(+) distribution was largely unbalanced, and, in the next 3 h, K(+) continued to flow in the extracellular space (about 24 mmol). After rebalancing, about 80% of the K(+) mass that was removed derived from the intracellular compartment. In conclusion, the Na-K pump plays a major role in K(+) apportionment between extracellular and intracellular compartments, and potassium dialysate concentration strongly influences pump activity.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
/
Soluções para Hemodiálise
/
Diálise Renal
/
ATPase Trocadora de Sódio-Potássio
/
Falência Renal Crônica
/
Modelos Biológicos
Tipo de estudo:
Clinical_trials
/
Prognostic_studies
Limite:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
País/Região como assunto:
Europa
Idioma:
En
Revista:
Artif Organs
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Itália