key: cord-0819480-20vivzv5 authors: Fernández Miró, M; Marin Arguedas, A; Ferrer Ruscalleda, L title: Syndrome of inappropriate antidiuretic hormone secretion associated to a SARS-CoV-2 pneumonia date: 2020-11-19 journal: Med Clin (Barc) DOI: 10.1016/j.medcli.2020.10.003 sha: 220ed1c8d5a6dfb69e79d976d7a690c98cde165e doc_id: 819480 cord_uid: 20vivzv5 nan The case report represents and exceptional insight in clinical endocrinology because we describe a new manifestation of coronavirus disease. A wide variety of clinical manifestations have been described in patients with COVID-19 infection, but to our knowledge, no endocrinological disorders have been described in. Since electrolyte disorders are frequent in hospitalized patients, we would like to emphasize the importance of identifying the etiology of hyponatremia for treatment implications which can influence the prognostic in the patient with SARS-CoV-2 pneumonia. Coronavirus. SIADH. Hyponatremia. SARS-CoV-2. Hyposmolarity. Pandemic. A fifty-two year old man, without toxic habits and on treatment with an angiotensinconverting enzyme inhibitor for arterial hypertension and with no other previous diseases presented to the emergency room with cough and fever of 39ºC of ten days duration, and SIADH is a common cause of hyponatremia in patients admitted to hospital. The median age of SIADH-associated aetiology is 70 years (range: 38-88). It is associated to higher mortality and morbidity and with a delay in hospital discharge. SIADH diagnostic criteria include serum Na <135 mmol/l, serum osmolarity <275mOsm/Kg, inadequate urine Page 3 of 4 J o u r n a l P r e -p r o o f concentration >100 mOsm/Kg, the absence of hypo-or hypervolemia signs, urine Na >40 meq/l with a salt and a normal fluid intake. Hypothyroidism, suprarenal insufficiency, renal failure or diuretic intake must be discarded. The most frequent causes of SIADH include malignancies, lung diseases, different kinds of drugs and central nervous system disorders. In 2003, hyponatremia associated to SARS infection was reported in 60% of patients 1 . Even though no specific data are available on the association of hyponatremia in SARS-CoV-2 infection, a recent study has described a 50% prevalence, although reporting a small number of patients 2 . Previous studies have related SIADH to lung diseases reaching prevalence between 10-45% in patients affected by microcytic pulmonary carcinoma 3 . Influenza type A virus infections have been related to SIADH in a few number of cases. In paediatrics, SIADH was detected in 18% of children under 12 month who were admitted for respiratory syncytial virus bronchiolitis, observing a higher incidence of pneumonia and intensive care requirements 4 . The incidence of hyponatremia in patients admitted for communityacquired pneumonia was 8.3%, with a 46% of them caused by SIADH 5 . We report this case to point to the importance of detecting the aetiology of hyponatremia due to treatment considerations. Current guidelines usually recommend caution with extra fluid therapy in patients with serious COVID-19 due to risk of respiratory distress. The finding that hyponatremia may be present in up to 50% of patients with COVID-19 admitted to hospital highlights the importance of a differential diagnosis including SIADH in this group of patients. Outcomes and prognostic factors in 267 patients with severe acute respiratory syndrome in Hong Kong Clinical features, laboratory characteristics, and outcomes of patients hospitalized with coronavirus disease 2019 (COVID-19): Early report from the United States Paraneoplastic syndromes: an approach to diagnosis and treatment Association between moderate-severe bronchiolitis and syndrome of inappropriate antidiuretic hormone secretion in emergency departments Hyponatraemia in patients with community-acquired pneumonia; prevalence and aetiology, and natural history of SIAD