Unusually low levels of serum inorganic phosphorus have been sporadically described in patients in hepatic coma. Amatuzio et al.,1 in 1952, studied 15 patients with portal cirrhosis and impending coma. In 11 of these patients the serum inorganic phosphorus was measured, and was less than 2.0 mEq. per liter in 10 of them. They suggested that an inadequate diet prior to admission or an associated steatorrhea might be responsible for the hypophosphatemia. In 1956, Roberts et al.2 reported on the electrolyte alterations in hepatic coma and described hypophosphatemia as an occasional finding. They felt that the drop in serum phosphorus was secondary to an associated respiratory alkalosis.
We have recently observed 4 patients in hepatic coma with marked hypophosphatemia. A slow return of the serum phosphorus levels to normal was noted as the cerebral dysfunction improved. Three patients had Laennec's cirrhosis, and the other had fulminating viral hepatitis.