Year: 2019
Type: article
Study design: Observational Study
Abstract: INTRODUCTION: A relationship between high levels of serum potassium and mortality has been previously described in patients undergoing hemodialysis. However, some patients may present low levels of potassium because of the improvement in hemodialysis technique or a poor nutritional status. Anyway, the “low” potassium dialysate concentration, which rapidly decreases serum potassium and often brings it to hypokalemic levels, is considered as a risk factor for life-threatening arrhythmias. The aims of this study are to evaluate the effect of different ranges of serum potassium in all-cause mortality of HD patients. METHODS: Retrospective multicenter non-interventional study in a Spanish cohort of patients receiving hemodialysis between January 2017 and December 2018 in Nephrocare Spain (FMC). Demographic data, dialysis clinical parameters, electrolytes and laboratory values measured at the first month of the evaluation period were settled as baseline. Patients were accordingly divided in groups based on the serum potassium at baseline and the DP concentrate during all the study period (DP of 1.5 mmol/L, 2.0 mmol/L, 3.0 mmol/l or shifted from 1.5 to 2.0 mmol/l). Differences between groups were performed by ANOVA, Kruskal-Wallis or Chi-Square test as required. All-cause mortality analysis was performed by Kaplan-Meier curves and univariate and multivariate COX regression stablishing December 2018 as the end-point of follow-up. RESULTS: 4647 prevalent hemodialysis patients (12-92 months) with a mean age of 70.2±13.9 years old, 37% female, from 58 FMC-Spain centers were evaluated. The number of patients in each group of serum potassium was 257 G1 (<3.5 mEq/L), 1386 G2 (3.5-4.5 mEq/L), 2185 G3 (4.5-5.5 mEq/L), 555 G4 (5.5-6 mEq/L) and 264 G5 (>6 mEq/L). Significantly, patients in G1 had lower body mass index and albumin levels and higher C-reactive protein levels. During the study period 25.9% of the patients (4.6 mEq/L median of serum potassium) changed DP from 1.5 to 2.0 mmol/L, 53.1% remained in DP of 1.5 mmol/l, 18.9% in 2.0 mmol/l and 2% in 3.0 mmol/l. All-cause mortality was significantly higher in the patients with serum potassium levels <3.5 mEq/L (Log-Rank=24.5; P<0,001 and HR univ 1.71 (1.31-2.2), p<0.01) (see figure 1). Moreover, age, Charlson index, body mass index, hemoglobin, C-reactive protein and albumin levels seem to be also modulating mortality risk. CONCLUSIONS: Our results suggest that levels of serum potassium may be related with changes in mortality risk in HD patients. Thus, serum potassium levels <3.5 mEq/L seem to be related to an increase of 34% of the mortality risk in HD patients with a worse nutritional and inflammatory status. Until controlled studies of different dialysate potassium concentrations and their effect on patient outcome, we should carefully consider dialysate potassium levels that may better balance risks and benefits according the patient clinical conditions and the pre-dialysis serum potassium levels
Language: English
Subfield: Nephrology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2949560366