AWAKENING OF A SLEEPING CRANIAL DIABETES INSIPIDUS IN COVID-19 INFECTION

Abstract

INTRODUCTION
Steroids, primarily dexamethasone is currently the mainstay of treatment for COVID-19 patients with respiratory distress and organising pneumonia. Its role here is mainly as an anti-inflammatory. However, it is also responsible to unmask hormonal deficiencies such as Cranial Diabetes Insipidus.

RESULTS
A 43-year-old female was admitted for category 2 COVID-19 infection. She has been unwell prior to this with intermittent headaches, abdominal pain and vomiting. During one of her admissions, brain MRI revealed she has a partial empty sella, however no hormonal  work up was done. She has no history of postpartum haemorrhage. In this current admission, she required IV hydration for poor oral intake. She had no documented episodes of hypotension or hypoglycaemia. Due to progression to category 4 COVID-19, she was started on IV hydrocortisone 100 mg TDS which was subsequently switched to IV dexamethasone 6 mg OD. During her hospital stay, she developed severe hypernatremia with a highest sodium concentration of 165 mmol/L. Intake and output charting exhibited polyuria with urine output up to 3 L/day, serum osmolarity of 346 mOsm/kg and urine osmolarity of 86 mOsm/kg. She responded well to subcutaneous desmopressin with a reduction of sodium to 157mmol/L over 24 hours and an ability to concentrate her urine. In patients with pituitary dysfunction, with reduced glucocorticoid production, there is reduction in AVP dependent water diuresis; with steroid replacement, there may be an exaggerated response to AVP and hence, severe polyuria. Due to the lung involvement, patients with COVID-19 infection are usually maintained at an equal or slightly negative fluid balance which could have caused the acute worsening of hypernatremia.

CONCLUSION
We need to be attuned to fluid and electrolyte imbalance in patients with COVID-19 infection especially in those with pituitary dysfunction.