Effects of Alkalinization and Rehydration on Plasma Potassium Concentrations in Neonatal Calves with Diarrhea

Abstract

BackgroundIncreased plasma potassium concentrations (K+) in neonatal calves with diarrhea are associated with acidemia and severe clinical dehydration and are therefore usually corrected by intravenous administration of fluids containing sodium bicarbonate.ObjectivesTo identify clinical and laboratory variables that are associated with changes of plasma K+ during the course of treatment and to document the plasma potassium‐lowering effect of hypertonic (8.4%) sodium bicarbonate solutions.AnimalsSeventy‐one neonatal diarrheic calves.MethodsProspective cohort study. Calves were treated according to a clinical protocol using an oral electrolyte solution and commercially available packages of 8.4% sodium bicarbonate (250–750 mmol), 0.9% saline (5–10 L), and 40% dextrose (0.5 L) infusion solutions.ResultsInfusions with 8.4% sodium bicarbonate solutions in an amount of 250–750 mmol had an immediate and sustained plasma potassium‐lowering effect. One hour after the end of such infusions or the start of a sodium bicarbonate containing constant drip infusion, changes of plasma K+ were most closely correlated to changes of venous blood pH, plasma sodium concentrations and plasma volume (r = −0.73, −0.57, −0.53; P < .001). Changes of plasma K+ during the subsequent 23 hours were associated with changes of venous blood pH, clinical hydration status (enophthalmos) and serum creatinine concentrations (r = −0.71, 0.63, 0.62; P < .001).Conclusions and Clinical ImportanceThis study emphasizes the importance of alkalinization and the correction of dehydration in the treatment of hyperkalemia in neonatal calves with diarrhea.

Effect of Intravenous Small‐Volume Hypertonic Sodium Bicarbonate, Sodium Chloride, and Glucose Solutions in Decreasing Plasma Potassium Concentration in Hyperkalemic Neonatal Calves with Diarrhea

“…However, in the light of those findings it needs to be clearly emphasized that it was the aim of the present study to compare the potassium‐lowering efficiency of different hypertonic infusion solutions in the initial treatment of hyperkalemic calves and not to test the resuscitative effect of a single injection of hypertonic infusion solution and subsequent suckling of an oral electrolyte solution. Nevertheless, given the facts that hyperkalemia in neonatal diarrheic calves is associated with marked dehydration and that an incomplete restoration of potassium homeostasis was even observed in calves of groups NaBic in spite of alkalinization and correction of acidosis, our findings suggest that rehydration should be another goal in the treatment of hyperkalemic calves as also indicated by the results of a recent observational study 17. Although not assessed in the present study, it is likely that administration of an additional volume of crystalloid infusion solutions would have resulted in a more rapid decline in c K through a more sustained plasma volume expansion and renal potassium excretion.…”

“…An immediate and sustained potassium‐lowering effect of hypertonic (8.4%) sodium bicarbonate infusion solution has already been demonstrated in previous studies,17, 18, 38 with the observed initial decrements of c K being most closely associated with increases in venous blood pH 17. Despite those findings, it still remained to be elucidated if the potassium‐lowering effect of sodium bicarbonate‐containing infusion solutions is related to the administered sodium load, plasma volume expansion, or alkalinization.…”

“…Acute hyperkalemia should therefore be considered as an emergency, and treatment objectives should focus on rapid correction of hyperkalemia. Although it is well known that the correction of a hyperkalemic state can be achieved by intravenous administration of large volumes of fluids containing sodium bicarbonate, sodium chloride, or glucose solutions,16, 17, 18, 19 the underlying mechanisms and the efficacy of different infusion solutions in the initial treatment have not been fully explored. Specifically, it needs to be determined how much of the return of potassium homeostasis is due to volume expansion (dilutional effect), rehydration with concomitant restoration of renal function (excretional effect), or intracellular translocation of potassium ions in response to alkalinization, a sodium‐induced strong ion effect, or the action of endogenous insulin.…”

“…Intravenous administration of hypertonic (8.4%) sodium bicarbonate solution induces an immediate and sustained decrease in c K, which is most closely associated with a rapid increase in venous blood pH and a rapid improvement in hydration status 17. In general, hypertonic sodium‐containing infusion solutions such as 8.4% sodium bicarbonate or 7.2% sodium chloride (saline) have a sound physiologic basis in the initial treatment of affected calves as these solutions not only induce rapid plasma volume expansion and correct hyperkalemia, but they also enhance the redistribution of potassium ions into cells.…”

Effets de la perfusion intensive sur quelques paramètres sanguins chez des veaux atteints de diarrhée aiguë

“…Dans une diarrhée, on observe donc une augmentation de taux d'hématocrite, du taux des protéines totales, de l'urée et de la créatinine suite à la diminution de la volémie et l'augmentation de la concentration sanguine (Smith, 2009) et une diminution du pH et du bicarbonate suite à l'acidose (Bednarski et al, 2015). Dans le traitement de la diarrhée, la réhydratation par voie orale ou parentérale reste la mesure la plus importante d'une part pour compenser les pertes et d'autre part restaurer la fonction rénale (Smith, 2009 ;Smith et Berchtold, 2014 ;Trefz et al, 2015). Le but de cette étude est d'évaluer les effets d'une perfusion intensive chez des veaux atteints de diarrhée aiguë sur les paramètres sanguins et notamment l'hématocrite, les protéines totales, la créatinine et l'urée plasmatiques, le pH, l'excès de base (BE) et le bicarbonate dans le sang.…”