RESUMEN
Hyponatremia is a commonly encountered electrolyte imbalance with varied etiology. Hyponatremia can be broadly classified as hypotonic, isotonic, and hypertonic hyponatremia based on the tonicity of plasma. Hypotonic hypovolemia is further classified as hypovolemic, euvolemic, and hypervolemic hyponatremia based on the volume status. Gastrointestinal fluid and electrolyte losses, secondary to vomiting and diarrhea, is an important predisposition to hypotonic hypovolemic hyponatremia. The renin-angiotensin-aldosterone system (RAAS) and antidiuretic hormone (ADH) play a pivotal role in maintaining intravascular volume and serum sodium concentration. Dexamethasone is a potent glucocorticoid with minimal mineralocorticoid activity. It negatively affects the hypothalamic-pituitary-adrenal axis and the renin-angiotensin-aldosterone system, particularly with prolonged administration. In the index case, acute severe hypovolemic hyponatremia ensued on the third post-procedure (endovascular embolization of traumatic carotico-cavernous fistula (CCF)) day while the patient was on intravenous dexamethasone. This case underscores that even small fluid and electrolyte imbalance in the setting of dexamethasone therapy may lead to severe hypovolemic hyponatremia, which requires specific therapy.
RESUMEN
We report the first case of Coronavirus Disease 2019 (COVID-19)-associated brain abscess caused by a rare Trichosporon species, T. dohaense. The patient was a known diabetic and had received systemic corticosteroids for the treatment of COVID-19. He underwent craniotomy and evacuation of abscess. The pus aspirate grew a basidiomycetous yeast, morphologically resembling Trichosporon species. The isolate was initially misidentified by VITEK® MS due to lack of mass spectral database of T. dohaense. Accurate identification was achieved by internal transcribed spacer-directed panfungal polymerase chain reaction. The patient had a favorable outcome following surgical intervention and antifungal therapy.