Hyponatremia and Encephalopathy in a 55-Year-old Woman with Syndrome of Inappropriate Antidiuretic Hormone Secretion as an Isolated Presentation of SARS-CoV-2 Infection

Severe hyponatremia in a mild COVID-19 patient: diagnostic challenges of SIADH and adrenal insufficiency

This case report presents a 57-year-old Japanese woman with mild COVID-19 who developed severe symptomatic hyponatremia and altered consciousness, notably without pneumonia or central nervous system infection. Initial findings, including low plasma osmolality, high urine osmolality, and elevated IL-6 levels, suggested that the syndrome of inappropriate antidiuretic hormone secretion (SIADH) was the primary cause of her hyponatremia. While initial saline infusion offered temporary symptom relief, sodium levels remained unstable, leading to intermittent steroid therapy. Her improvement with steroids, alongside additional hormonal testing, raised the possibility of partial adrenal insufficiency as a complicating factor. Although secondary adrenal insufficiency in COVID-19 cases has been previously reported, its exact contribution to hyponatremia remains unclear. This case underscores the diagnostic complexities in managing hyponatremia associated with COVID-19, as SIADH is often the leading cause but may not fully explain persistent cases unresponsive to standard treatments. The report also emphasizes the importance of considering adrenal insufficiency in similar cases, particularly given COVID-19's potential impact on the hypothalamic-pituitary-adrenal axis. This case highlights the need for further research into COVID-19's effects on hormonal regulation, as such disruptions may play a key role in COVID-19-related electrolyte imbalances.

Severe Hyponatremia in the Setting of COVID-19-Associated Syndrome of Inappropriate Antidiuretic Hormone: A Case Report

The COVID-19 pandemic has resulted in significant worldwide morbidity and mortality. One of the less studied clinical manifestations is Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) associated with COVID-19 pneumonia. We present a single case of COVID-19 pneumonia-associated SIADH in a 71-year-old male with a history of alcohol use disorder. This case highlights the importance of full diagnostic workup of the underlying cause of hyponatremia to avoid significant morbidity.

Prevalence and outcomes of hyponatremia among COVID-19 patients: A systematic review and meta-analysis

Objectives

On March 2020, the WHO declared coronavirus disease 2019 (COVID-19) pandemic. COVID-19 is associated with various clinical syndromes, with electrolytes imbalances involved. This review aims to quantify the prevalence and outcomes of hyponatremia among COVID-19 patients, as well as to review the underlying pathophysiological mechanisms of hyponatremia among these patients.

Methods

Using Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines, we conducted a systematic literature search using the electronic databases of Google Scholar, MEDLINE (PubMed), WHO Virtual Health Library, and ScienceDirect, without limitations regarding gender, geographical area, race or publication date, up until December 13, 2021. Primary outcomes measured were mortality, intensive care unit (ICU) admission, assisted ventilation need, and length of hospital stay (LOS). Secondary outcome was the mechanism underlying hyponatremia among COVID-19 patients.

Results

From a total of 52 included studies, 23 underwent quantitative analysis. For the primary outcomes; proportions, odds ratios (OR), and standardized mean difference (SMD) were calculated using random effects model. The prevalence of hyponatremia was found to be 25.8%. Hyponatremia was found to be significantly associated with increased odds for mortality (OR = 1.97[95% CI, 1.50-2.59]), ICU admission (OR = 1.91 [95% CI, 1.56-2.35]), assisted ventilation need (OR = 2.04 [95% CI, 1.73-2.38]), and with increased LOS (SMD of 5.74 h [95% CI, 0.092-0.385]). Regarding the mechanisms underlying hyponatremia, syndrome of inappropriate anti-diuretic hormone secretion (SIADH) was most commonly reported, followed by adrenal insufficiency, and finally hypovolemic hyponatremia due to gastrointestinal losses.

Conclusion

Hyponatremia among COVID-19 patients is generally associated with poor outcomes, with SIADH being the most common underlying mechanism.

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.

Hypernatraemia and low eGFR at hospitalization in COVID-19 patients: a deadly combination

Background

The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on the general population and the burden of pre-existing comorbidities has heavily affected the outcome of the infection. Hyponatraemia has been frequently described. Conversely, hypernatraemia has rarely been described in COVID-19.

Methods

The studied cohort encompasses all COVID-19 patients consecutively admitted to the Messina Hospital, Italy, during the first wave of the epidemic. Since healthcare structures were not overwhelmed at that time, indications for hospitalization were homogeneous throughout the study period. Serum sodium levels, kidney function [estimated glomerular filtration rate (eGFR)], demographic and clinical characteristics were recorded at admission. Correlation between mortality, sodium and eGFR was evaluated by survival curves and univariate and multivariate regression models.

Results

Baseline biochemical and clinical data at the time of admission were available for 115 COVID-19-confirmed patients. The median age at admission was 73 years (48% men), with a median Charlson Comorbidity Index of 4. A total of 23.5% of patients presented with a sodium level ≥146 mmol/L, while 7.8% had sodium <135 mmol/L. Hypernatraemic patients were older, with higher comorbidity. Age, hypernatraemia and reduced eGFR were associated with increased mortality in both univariate and multivariate regression models (P < 0.001). The combination of hypernatraemia and reduced renal function at admission had an odds ratio of 47.67 (95% confidence interval 10.08–225.43) of dying compared with patients with an eGFR ≥60 mL/min and sodium <145 mmol/L.

Conclusions

Our study suggests that the association between hypernatraemia and reduced eGFR at referral is a highly relevant prognostic marker for death during hospitalization. The role of this association should be further tested in larger, multicentre cohorts.