Hi, I can understand your concern. Your son may have landed in liver cell failure which is most likely due to sepsis (infection spread through blood) caused by pneumonia. Due to pneumonia (or any other severe infection) there is spread of infective organism like bacteria through blood. Depending upon type of organism various presentations may be there. In response to spread of infection in blood our immunity try to restrict infection while doing this there is release of various type of factors which has good and bad effect over body. As a bad effect there is decrease in blood pressure which lead to decreased blood supply to important organs like kidney or liver. Due to effect of decreased blood supply & effect of infection there is liver damage which lead to raised liver enzymes as in your son s case. Liver cannot remove ammonia from the blood and its level rises. At present your son looks like in recovering phase as ammonia has came down to normal. Hope this helps you.