A Case Series of Acute Symptomatic Hyponatremia due to SIADH in mild COVID-19 Infection

Abstract Syndrome of Inappropriate anti diuretic hormone (SIADH) is one of the commonest cause of hyponatremia among medical inpatients. Over recent years, the evolution of SARS-COV-2 infection has led to atypical presentations of acute symptomatic hyponatremia secondary to isolated SIADH exclusive of pneumonia. We report an unusual case series of acute symptomatic hyponatremia secondary to SIADH in Category 2 COVID-19 infection. In our case series, all the patients presented with symptoms of acute severe hyponatremia and were incidentally screened positive for the SARS-COV-2 virus without respiratory tract symptoms and normal chest imaging. They were fully vaccinated and boosted at least three months before the presentation. Clinical and biochemical workups confirmed SIADH in all three patients. They were treated with hypertonic saline initially, followed by fluid restriction as per recommendations. It was postulated that the most likely mechanism responsible for the inappropriate ADH secretion is mediated by the increased inflammatory cytokines, especially interleukin-6 and the direct effect of the SARS-COV2 infection. In the context of the COVID-19 pandemic, atypical presentations of acute symptomatic hyponatremia without an apparent cause could be an isolated manifestation of SARS-COV-2 infection. Awareness of this condition is essential for the early institution of the treatment protocol for this reversible and life-threatening disorder