Is osmotic demyelination a concern dialyzing hyponatremic patients?

Dysnatremias in Chronic Kidney Disease: Pathophysiology, Manifestations, and Treatment

The decreased ability of the kidney to regulate water and monovalent cation excretion predisposes patients with chronic kidney disease (CKD) to dysnatremias. In this report, we describe the clinical associations and methods of management of dysnatremias in this patient population by reviewing publications on hyponatremia and hypernatremia in patients with CKD not on dialysis, and those on maintenance hemodialysis or peritoneal dialysis. The prevalence of both hyponatremia and hypernatremia has been reported to be higher in patients with CKD than in the general population. Certain features of the studies analyzed, such as variation in the cut-off values of serum sodium concentration ([Na]) that define hyponatremia or hypernatremia, create comparison difficulties. Dysnatremias in patients with CKD are associated with adverse clinical conditions and mortality. Currently, investigation and treatment of dysnatremias in patients with CKD should follow clinical judgment and the guidelines for the general population. Whether azotemia allows different rates of correction of [Na] in patients with hyponatremic CKD and the methodology and outcomes of treatment of dysnatremias by renal replacement methods require further investigation. In conclusion, dysnatremias occur frequently and are associated with various comorbidities and mortality in patients with CKD. Knowledge gaps in their treatment and prevention call for further studies.

Hemodialysis treatment in patients with severe electrolyte disorders: Management of hyperkalemia and hyponatremia

Significant deviations of serum potassium and sodium levels are frequently observed in hospitalized patients and are both associated with increased all‐cause and cardiovascular mortality. The presence of acute or chronic renal failure facilitates the pathogenesis and complicates the clinical management. In the absence of reliable outcome data in the context of dialysis prescription, requirement of renal replacement therapy in patients with severe electrolyte disturbances constitutes a therapeutic challenge. Recommendations for intradialytic management are based on pathophysiologic reasoning and clinical observations only, and as such, heterogeneous and limited to expert opinion level. This article reviews current strategies for the management of severe hyperkalemia and hyponatremia in hemodialysis patients.

Valacyclovir Neurotoxicity and Nephrotoxicity in an Elderly Patient Complicated by Hyponatremia

A 66-year-old women with no history of renal disease was admitted due to a coma and acute kidney injury with a serum creatinine level of 7.44 mg/dL which were ascribed to valacyclovir neurotoxicity and nephrotoxicity, respectively. She had received valacyclovir at a standard dosage for the treatment of herpes zoster and was finally discharged, having fully returned to her normal baseline mental status with a recovered serum creatinine level of 0.68 mg/dL. We feel that awareness of this pathology remains a challenge for physicians and therefore strongly recommend the further accumulation of experiences similar to our own. Our experience underscores the pitfalls of administering valacyclovir to elderly patients who barely appear to have a favorable renal function. Several concerns regarding the therapeutic management, including blood purification strategies, that emerged in this case are also discussed.

Treatment of severe hyponatremia in patients with kidney failure: role of continuous venovenous hemofiltration with low-sodium replacement fluid

Patients with hypervolemic hyponatremia and kidney failure pose a special therapeutic challenge. Hemodialysis to correct volume overload, azotemia, and abnormal electrolyte levels will result in rapid correction of serum sodium concentration and place the patient at risk for osmotic demyelination syndrome. We present a patient with acute kidney injury and severe hypervolemic hypotonic hyponatremia (serum sodium<100 mEq/L) who was treated successfully with continuous venovenous hemofiltration. This teaching case illustrates the limitations of hemodialysis and demonstrates how to regulate the sodium correction rate by single-pool sodium kinetic modeling during continuous venovenous hemofiltration. Two methods to adjust the replacement fluid to achieve the desired sodium concentration are outlined.

Successful treatment of extreme hyponatremia in an anuric patient using continuous venovenous hemodialysis

Rapid correction of severe hyponatremia can result in osmotic demyelination syndrome. Patients with severe hyponatremia and renal failure requiring dialysis pose a therapeutic challenge since the use of conventional intermittent hemodialysis will result in a rapid correction of the serum sodium level. We report the case of a 52-year-old woman with extreme hyponatremia and severe acute kidney injury, who was successfully treated with continuous venovenous hemodialysis using a modified dialysate solution with a low sodium concentration that was adjusted on a daily basis.

Dysnatremias in patients with kidney disease

Dysnatremias are among the most common electrolyte disorders in clinical medicine. Recent studies have shown that individuals with chronic kidney disease also are afflicted by these electrolyte disorders. Furthermore, their presence imparts an increased risk of mortality. In this review, we discuss studies in experimental animals and in humans that have attempted to establish the mechanisms responsible for limiting urinary dilution and urinary concentration in progressive kidney disease. The clinical implications of these disorders in water excretion are discussed in the setting of optimal water intake as kidney disease progresses. This review emphasizes the management of patients with chronic kidney disease who have marked abnormalities in serum sodium concentrations and gives specific recommendations for modifications in renal replacement therapy prescription in hyponatremic patients with end-stage renal disease.