Disorders of sodium balance in COVID-19 patients: two Tunisian patients report.

Coronavirus disease 2019 (COVID-19) was first reported in December 2019. The disease is caused by severe acute respiratory syndrome virus corona virus 2 (SARS-CoV-2). Mild respiratory symptoms are the most common manifestations of SARS-CoV-2, but new signs are constantly being discovered as it spreads. Disorders of sodium balance are increasingly described in patients with SARS-CoV-2. We report, here, the cases of two patients presented with COVID-19 and in whom we discovered sodium disorders. The first patient is a 74-year-old man who presented with fatal hypernatremia. The second patient is a 66-years-old man presented with COVID-19 and euvolemic hyponatremia attributed to syndrome of inappropriate anti-diuretic hormone secretion (SIADH). This hyponatremia persisted long after the respiratory signs disappeared. Sodium balance disorders are increasingly described in the literature; special attention should be paid to the electrolyte status of COVID-19 patients. Pathophysiological mechanisms associating SARS-CoV-2 with these disorders are being studied.

Adipsic hypernatremia in two patients with AIDS and cytomegalovirus encephalitis.

In patients with acquired immune deficiency syndrome (AIDS), hypoosmolality is frequently observed, whereas hypernatremia is distinctly rare. We report two patients with advanced AIDS and cytomegalovirus (CMV) encephalitis, who developed severe hypernatremia without any thirst sensation, that is, adipsic hypernatremia. Both developed severe hypernatremia of up to 164 and 162 mmol/L, with serum osmolalities of 358 and 344 mOsmol/kg while remaining alert and denying thirst. Serum antidiuretic hormone (ADH) levels were 0.9 and 1.5 pg/mL, inappropriately low for the concomitant serum osmolalities. Vital signs were stable. During hypernatremia, urine osmolalities were 327 and 340 mOsmol/kg, and urine Na+ levels were 56 and 119 mmol/L, respectively. Periventricular white matter lesions were seen on cerebral nuclear magnetic resonance imaging (NMRI) in case 1, but the pituitary appeared normal in both cases. Survival after onset of hypernatremia was 6 and 4 weeks, respectively. Autopsy in case 1 showed typical findings of CMV encephalitis but normal pituitary, confirming that infection with HIV or CMV most likely caused the dysfunction of the central osmostat.

A prospective clinical study of patients with hypernatraemic dehydration.

In a clinical prospective 3-year study of 158 children aged 2 weeks to 14 years with hypernatraemic dehydration (serum sodium 150 mmol/l or more), infants predominated (61.4%). The 158 children with hypernatraemia accounted for 13.7% of all children admitted with gastroenteritis over the same period, and significant aetiological factors included the use of artificial feeds, differences between the children with hypernatraemia and those with normo- or hyponatraemia, P < 0.001, P < 0.001, respectively; the use of breast milk, P < 0.001, P < 0.001, respectively; nutritional status, P < 0.001, P < 0.001, respectively; and clinical state of mild to moderate dehydration P < 0.001; P < 0.001, respectively; but not with patients considered severely dehydrated. There was also a significant difference between the presence of neurological features in hyper- and normonatraemic patients P < 0.001; in hyper- and hyponatraemic patients P < 0.05, and in mortality rate between hyper- and normonatraemic patients, P < 0.05 but not between hyper- and hyponatraemic patients. A history of refusal to feed or vomiting was obtained in 41 children (25.9%). The mean serum sodium was 155.5 mmol/l (range 150-189 mmol/l); mean serum urea 7.7 mmol/l (range 1-18.9 mmol/l). Hypernatraemic dehydration remains an important and serious complication of childhood gastroenteritis in our area of study. The use of artificial milk feeds is contributory, and well-nourished babies appear more at risk. We recommend more liberal water intake during gastroenteritis and the public should also be educated on and made more aware of this condition.