COVID and the Salt Story

Vidya Saketharaman, Aslesha Vijaay Sheth*

Department of Emergency Medicine, Kauvery Hospital, Chennai, India



Each wave of COVID brought with its unique presentations! Our emergency physicians learned to suspect COVID with tell-tale signs, since the definitive RT-PCR COVID results reports become available only after 6-8 h.

During the third wave, we observed that COVID infected elderly patients who presented with altered sensorium. COVID had proclaimed its affinity for the brain, affecting olfactory bulb, substantia nigra, posterior cingulate gyrus, neurons, astrocytes, oligodendrocytes, microglia, and ventrolateral medulla [1].

We noticed the following in many elderly patients during the third wave.


DM, Diabetes Mellitus; HT, Hypertension; CAD, Coronary artery disease; BA, Bronchial asthma; CVA, Cerebrovascular accident; Ct/CT, Computed tomography

Our index patients presented with seizures and hyponatremia under the spectrum of COVID encephalopathy.

Pathogenesis of hyponatremia in COVID positive elderly patients

  1. Tea-toast diet: owing to decreased appetite and decreased intake, the sodium balance was disturbed, which in turn stimulates the osmoreceptors and baroreceptors causing increased ADH secretion [2].
  2. COVID lung injury causes reduced left atrial stretch and volume causing increased ADH secretion [2].
  3. The cytokines releases, a part of COVID pathogenesis, directly stimulate non-osmotic release of ADH [2].
  4. Stress by itself stimulates cortical neurons of the hypothalamus causing ADH release [2].

All these can lead to SIADH in elderly COVID positive patients.

The HOPE COVID-19 registry analysis indicate that hyponatremia is associated with poor prognosis in COVID patients [3].


Elderly patients, who presented during the third wave of the pandemic in our part of the subcontinent, mostly presented atypically with sudden onset altered sensorium, in the absence of fever, and were found to have hyponatremia, which raised suspicion of the probability of COVID infection. We advocate caution and a high index of suspicion of COVID positivity in such elderly populations during future waves.


[1] Boldrini M, Canoll PD, Klein RS. How COVID-19 Affects the Brain JAMA Psychiatry. 2021;78(6):682-683.

[2] Gheorghe G, Ilie M, Bungau S, et al. Is There a Relationship between COVID-19 and Hyponatremia? Medicina (Kaunas). 2021;57(1):55.

[3] Ruiz-Sánchez JG, Níºí±ez-Gil IJ, Cuesta M, et al. Prognostic Impact of Hyponatremia and Hypernatremia in COVID-19 Pneumonia. A HOPE-COVID-19 (Health Outcome Predictive Evaluation for COVID-19) Registry Analysis. Front Endocrinol (Lausanne). 2020;11:599255.


Dr. Vidya Saketharaman

Emergency Care


Dr. Aslesha Vijaay Sheth

Consultant & Clinical Lead