Email updates

Keep up to date with the latest news and content from BMC Nephrology and BioMed Central.

Open Access Highly Accessed Research article

Haemodynamic consequences of changing potassium concentrations in haemodialysis fluids

Luca Gabutti12*, Igor Salvadé2, Barbara Lucchini2, Davide Soldini1 and Michel Burnier3

Author Affiliations

1 Division of Nephrology, Ospedale la Carità, Via Ospedale, 6600 Locarno, Switzerland

2 Department of Internal Medicine, Ospedale la Carità, Locarno, Switzerland

3 Division of Nephrology, University Hospital of Lausanne, Lausanne, Switzerland

For all author emails, please log on.

BMC Nephrology 2011, 12:14  doi:10.1186/1471-2369-12-14

Published: 6 April 2011

Abstract

Background

A rapid decrease of serum potassium concentrations during haemodialysis produces a significant increase in blood pressure parameters at the end of the session, even if effects on intra-dialysis pressure are not seen. Paradoxically, in animal models potassium is a vasodilator and decreases myocardial contractility. The purpose of this trial is to study the precise haemodynamic consequences induced by acute changes in potassium concentration during haemodialysis.

Methods

In 24 patients, 288 dialysis sessions, using a randomised single blind crossover design, we compared six dialysate sequences with different potassium profiles. The dialysis sessions were divided into 3 tertiles, casually modulating potassium concentration in the dialysate between the value normally used K and the two cut-off points K+1 and K-1 mmol/l. Haemodynamics were evaluated in a non-invasive manner using a finger beat-to-beat monitor.

Results

Comparing K-1 and K+1, differences were found within the tertiles regarding systolic (+5.3, +6.6, +2.3 mmHg, p < 0.05, < 0.05, ns) and mean blood pressure (+4.3, +6.4, -0.5 mmHg, p < 0.01, < 0.01, ns), as well as peripheral resistance (+212, +253, -4 dyne.sec.cm-5, p < 0.05, < 0.05, ns). The stroke volume showed a non-statistically-significant inverse trend (-3.1, -5.2, -0.2 ml). 18 hypotension episodes were recorded during the course of the study. 72% with K-1, 11% with K and 17% with K+1 (p < 0.01 for comparison K-1 vs. K and K-1 vs. K+1).

Conclusions

A rapid decrease in the concentration of serum potassium during the initial stage of the dialysis-obtained by reducing the concentration of potassium in the dialysate-translated into a decrease of systolic and mean blood pressure mediated by a decrease in peripheral resistance. The risk of intra-dialysis hypotension inversely correlates to the potassium concentration in the dialysate.

Trial Registration Number

NCT01224314

Keywords:
Haemodynamics; hypotension; potassium; haemodialysis; dialysis fluids