key: cord-338857-9zbtngje authors: Tee, Louis Yunshou; Yap, Bernard; Sidhu, Gurinderjit Kaur; Goh, Kiat Sern; Rosario, Barbara Helen title: Atypical Presentation of COVID‐19 in an Older Adult: Lethargy and Vomiting from Severe Hypovolemic Hyponatremia date: 2020-07-08 journal: Geriatr Gerontol Int DOI: 10.1111/ggi.13990 sha: doc_id: 338857 cord_uid: 9zbtngje nan The Coronavirus 2019 (COVID-19) pandemic disproportionately affects older adults, who suffer from more severe infections and higher mortality rates [1] [2] [3] . 75% of known COVID-19 cases are aged over 50, and the case fatality rate ranges from 8% to 15% in patients aged above 70 4, 5 . Importantly, COVID-19 infections in older adults may present with atypical symptoms, posing a diagnostic challenge. For instance, COVID-19 can manifest in older patients as delirium or falls, without fever or respiratory symptoms 6, 7 . Here, we describe an older patient with COVID-19 pneumonia who presented with lethargy and vomiting contributed by severe hypovolemic hyponatremia. A 65-year-old Malay male presented to the Emergency Department with acute lethargy for the past one week, which he initially attributed to fasting during Ramadan. Over the past two days, he felt intermittently nauseous, and vomited small amounts of non-bloody, non-bilious gastric contents twice a day while fasting, but he did not have diarrhea or abdominal pain. He denied fever or respiratory symptoms. His family physician found leukopenia in his blood tests and referred him to the Emergency Department. Before his symptoms started, he was well and working fulltime. His only medication was oral allopurinol 100mg once a day for gout prophylaxis. Otherwise, he had no significant past medical history or family history. He did not consume supplements, was teetotal and never smoked. On examination, he was afebrile and hemodynamically stable with no supplemental oxygen required, but his oral mucosa was dry. Cardiac, respiratory, abdominal and neurological examinations were normal, and the patient was clinically euthyroid. This article is protected by copyright. All rights reserved. Blood investigations revealed severe hyponatremia (sodium concentration, 115mmol/L), a raised inflammatory marker (C-reactive protein, 29.5mg/L), and leukopenia (total leukocytes, 1.8x10 9 /L). Serum creatinine, urea, potassium and bicarbonate concentrations were unremarkable, and the patient was not anemic or thrombocytopenic. The elevated C-reactive protein and leukopenia prompted a search for the source of an occult infection, and consequently a chest X-ray revealed patchy airspace opacities in the middle and lower lobes of the right lung indicative of community-acquired pneumonia. Due to the COVID-19 outbreak in Singapore 8 , he was isolated in the Respiratory Infection Surveillance Ward 9 and a nasopharyngeal swab was obtained for a SARS-CoV-2 reverse transcriptase-polymerase chain reaction (RT-PCR) test, which was positive. Conversely, PCR for atypical organisms such as Mycoplasma, Chlamydophilia and Bordetella, were negative. Since the patient had no cough, we could not send sputum for tests. Further investigations were performed to determine the cause of the severe hyponatremia. A thyroid function test revealed a low thyroid stimulating hormone level of 0.221mIU/L, a normal free T4 level of 12.86pmol/L, and an undetectable free T3 level (<2.0mcg/dL). A short tetracosactrin (Synacthen) test conducted at 8am showed an adequate adrenal response (299nmol/L at 0mins; 630nmol/L, 30mins; 834nmol/L, 60mins). Blood and urine tests were not suggestive of Syndrome of Inappropriate Anti-Diuretic Hormone (SIADH; serum osmolarity, 256mOsm/kg; urine osmolarity, 83mOsm/kg; urine sodium, <20mmol/mL). The patient was reviewed by an endocrinologist, who diagnosed severe hypovolemic hyponatremia and euthyroid sick syndrome. This article is protected by copyright. All rights reserved. Having been diagnosed with mild COVID-19 pneumonia, the patient was transferred to the COVID-19 Isolation Ward. The patient was empirically treated with oral amoxicillin 875mg with clavulanate 125mg (Augmentin) twice a day and oral doxycycline 100mg twice a day for seven days, according to the hospital's antibiotic guidelines for community-acquired pneumonia. For his severe hypovolemic hyponatremia, the patient was judiciously hydrated with a slow intravenous isotonic saline infusion, and serum sodium concentration increased from 115 to 127mmol/L over one day, and then to 132mmol/L over four days. Subsequently, his lethargy, nausea and vomiting resolved. Since the patient remained afebrile and hemodynamically stable, with no supplemental oxygen required, he was not treated with antivirals. On the eighth day of his admission, the patient was discharged to a quarantine facility within the community. None of the healthcare workers who cared for the patient contracted COVID-19. To our knowledge, this is the first reported case of a COVID-19 infection that presented with lethargy and vomiting contributed by severe hypovolemic hyponatremia. Notably, SARS-CoV-2 binds to angiotensin-converting enzyme receptors, and is postulated to cause electrolyte imbalances (such as hyponatremia and hypokalemia) by inducing renal excretion of these electrolytes 10 . Moreover, this case highlights that, particularly in older persons, COVID-19 infections may have atypical presentations 2,3 . Therefore, since older adults are more susceptible to severe complications of COVID-19, clinicians should lower their threshold to test for COVID-19 in acutely ill older patients during COVID-19 outbreaks. Prompt surveillance and early diagnosis of COVID-19 are essential to prevent nosocomial Accepted Article This article is protected by copyright. All rights reserved. transmission of the disease, especially since delayed diagnosis has resulted in the infection of healthcare workers 6 . Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study COVID-19 in Older People: A Rapid Clinical Review COVID-19 and Older Adults: What We Know Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72 314 Cases From the Chinese Center for Disease Control and Prevention Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet Atypical presentation of COVID-19 in a frail older person Typically Atypical: COVID-19 Presenting as a Fall in an Older Adult Investigation of three clusters of The authors received no specific funding for this work. The authors declare no conflict of interest.