however , at least one of four characteristics was present : an increase in serum sodium to normal or hypernatremic levels in the first 48 hours , a change in the serum sodium concentration of more than 25 mmol per liter in the first 48 hours , a hypoxic-anoxic episode , and an elevation of serum sodium to hypernatremic levels in patients with hepatic encephalopathy .
C0242184
hypoxic
C0003130
anoxic