Effect of a new model of hemodialysis potassium removal on the control of ventricular arrhythmias

Abstract

The primary aim of this multicenter, prospective, randomized cross-over study was to clarify whether a new model of hemodialysis (HD) potassium (K) removal using a decreasing intra-HD dialysate K concentration and a constant plasma-dialysate K gradient (treatment B) is capable of reducing the arrhythmogenic effect of standard HD, which has a constant dialysate K concentration and decreasing plasma-dialysate K gradient (treatment A). The secondary aim was to verify whether this new model is clinically safe. In treatment B, the initial dialysate K concentration had to be 1.5 mEq/liter less than the plasma K concentration, and exponentially decrease to 2.5 mEq/liter at the end of HD. Forty-two chronic HD patients with an increase in premature ventricular complexes (PVC) during dialysis were enrolled from 18 participating centers, and randomly assigned to either sequence 1 (ABA) or sequence 2 (BAB). A pool of 333 of 378 expected ECG Holter recordings were checked for signal quality; 269 (71%) from 36 patients (86%) had a satisfactory signal quality and 108 were selected for analysis (1 per patient per period). There was a difference in the natural logarithm of the increase in PVC/hr and PVC couplets/hr during HD between treatments A and B (1.70 +/- 1.59 vs. 1.09 +/- 1.76 and 0.94 +/- 0.86 vs. 0.64 +/- 1.01, a reduction of 36% and 32%, P = 0.011 and 0.047, respectively) without any carry over effect (P = 0.61 and 0.24, respectively). The fact that this decrease of one third is due to a lower plasma-dialysate K gradient is supported by the observation that it was more evident during the first than the last two hours of HD (a reduction in the natural logarithm of the increase in PVC/hr and PVC couplets/hr of 60% and 60%, P 0.002 and 0.009, vs. 26% and 17%, P = 0.098 and 0.332, respectively): the initial plasma-dialysate K gradient was 2.3 times lower during treatment B than during treatment A, without adversely affecting pre-HD plasma K levels. These results could have a considerably clinical impact not only because of the possibility of physiologically decreasing the arrhythmogenic effect of HD, but also because this effect can be considered a "marker" of the electrophysiological derangement induced by the administration of standard HD three times a week for years ("electric disequilibrium syndrome").

Serum and Dialysate Potassium Concentrations and Survival in Hemodialysis Patients

“…MHD patients with extreme hyperkalemia are routinely treated with dialysate baths that contain very low K concentration and hence could experience transient hypokalemia that develops in a relatively rapid manner; this consideration does not apply to patients with predialysis hypokalemia, because supraphysiologic dialysate K concentrations are not used in practice. Indeed, avoiding a high intradialytic K gradient resulted in significantly fewer arrhythmias in a study that compared the routinely used fixed-dialysate K concentration strategy with one using a variable dialysate K concentration treatment (37). Variable dialysate K concentrations are unfortunately not routinely used in clinical practice, which poses a dilemma when treating patients with predialysis hyperkalemia: Should one use a higher (fixed) dialysate K concentration to avoid rapid shifts in serum K level and risk inadequate K clearance and subsequent hyperkalemia or administer dialysates with low K concentration to control K-mass balance while running the risk for intradialytic arrhythmias?…”

Does Timing of Dialysis in Patients with ESRD and Acute Myocardial Infarcts Affect Morbidity or Mortality?

“…This was significantly elevated in the group undergoing dialysis in the first 24 h ( Table 3). Despite differences in the timing of dialysis, there were no findings of increased morbidity (26, 36, and 20%, respectively; Figure 2) or mortality (11,18, and 13%, respectively; Figure 2). When evaluating our total patient population comparing those with morbidity in the peridialysis period with those without, there were no differences in age, the incidence of chest pain, diabetes, or congestive heart failure (Table 4); however, APACHE scores and history of previous AMI (Table 4) were significantly greater in the morbidity group, whereas the presence of STEMI approached significance (Table 5).…”

“…Procedures such as sustained low-efficiency daily dialysis may be the proper treatment in patients with ESRD and with AMI, through their slower and more physiologic approach to treatment of electrolyte and volume change. Alternatively, the use of a method that gradually increases the K gradient in intermittent dialysis may avoid complications (18,25). By decreasing episodes of hypotension and arrhythmia, careful dialysis may result in limiting infarct size and improve cardiac rehabilitation and mortality.…”

Avaliação da redução de potássio em hortaliças submetidas a diferentes métodos de cocção para possível utilização na dietoterapia renal

“…Tanto a hipocalemia -concentração do potássio no soro inferior a 3,5mEq/ l -quanto a hipercalemia -concentração plasmá-tica acima de 5,0mEq/l -sabidamente afetam a excitabilidade da célula do músculo cardíaco, propiciando o desenvolvimento de arritmias e morte súbita 1,12 .…”