Evaluating Hyponatremia in Non-Diabetic Uremic Patients on Peritoneal Dialysis

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.

A Systematic Review and Meta-Analysis: Hyponatremia Predicted All-Cause and Cardiovascular Mortality in Dialysis Population

BACKGROUND

Hyponatremia is one of the most common disorders of electrolytes. Some research studies reported that hyponatremia was closely associated with mortality in patients with dialysis. However, this viewpoint remains controversial.

OBJECTIVE

We aimed to do a systematic review and meta-analysis to assess the influence of hyponatremia on mortality in patients with dialysis.

METHODS

We identified the eligible studies that investigated the association between hyponatremia and mortality risk in patients under dialysis by searching systematically a series of databases including PubMed, Embase, Cochrane, Web of science, and Ovid from January 2011 to June 2020. Adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) were pooled.

RESULTS

From 1,116 records identified, 12 studies including prospective and retrospective cohort studies met our inclusion criteria. We found hyponatremia both at baseline (HR: 1.50 and 95% CI: 1.41-1.59) and in time-varying (HR: 1.63 and 95% CI: 1.44-1.84) were significantly correlated to all-cause mortality after multivariable adjusted. By the subgroup analysis, the same results were presented in hemodialysis (HR: 1.48 and 95% CI: 1.38-1.59) or peritoneal dialysis patients (HR: 1.52 and 95% CI: 1.37-1.70). We also observed that lower serum sodium was independently associated with cardiovascular death.

CONCLUSIONS

Hyponatremia was independently associated with all-cause and cardiovascular mortality, and it might predict adverse outcomes of patients under dialysis.

A case report of a man on peritoneal dialysis having intractable hyponatremia

RATIONALE

Hyponatremia is one of the most common electrolyte disorders in patients on peritoneal dialysis (PD). It can be associated with severe consequences, higher morbidity and mortality. Therefore, hyponatremia should be assessed and monitored more carefully in these patients.

PATIENT CONCERNS

A 55-year-old male PD patient progressively developed intractable hyponatremia was admitted to our hospital.

DIAGNOSES

The observation that no significant salt was lost in kidney and PD drainage prompted us to seek the underlying reasons for malnutrition and chronic inflammation. And cancer and tuberculosis were further suspected, although the exact nature at last was not clearly determined due to the unfavorable prognosis.

INTERVENTIONS

The hyponatremia can hardly be improved by adjusting ultrafiltration close to zero, increasing sodium intake from 2.5 g to 7g, and nutrition counselling to maintain protein intake 0.9-1.2 g/kg/day and calorie intake 27-35 kcal/kg/day. Due to poor general situation, he received tentative anti-tuberculosis treatment instead of surgery for intracranial space-occupying lesion.

OUTCOMES

He died at home with conservative therapy.

LESSONS

It highlighted the challenge for differential diagnosis and treatment in the hyponatremia on PD patient.