Toxic Fungi of Western North America

by Thomas J. Duffy, MD

Prognostic indicators for likely fatality

A simple classification for cases of amatoxin poisoning can be formed from the latency period and the prothrombin time. Most commonly that measurement of clotting time becomes prolonged in amanitin poisoning when the damaged liver produces less prothrombin. One can readily classify mild poisonings as those that have a latency period over 18 hours and a normal prothrombin time; moderately severe cases, as those with a latency period from 13-18 hours and an abnormally long prothrombin time (but less than 55 seconds) and severe cases as those having a latency of 12 hours or less and a prothrombin time of 55 seconds or more. As expected with biologic phenomena, the three criteria do not always correlate. The prothrombin time probably is the most closely correlated with death.

A 1991 review of 140 cases where some of a severely poisoned group died without recourse to transplantation showed that the fatality cases in these patients were best separated out on the basis of thromboplastin time (liver) and serum creatinine (kidney). In this study, the two best indicators for likely fatality were a thromboplastin time (35% of normal or less) despite moderate replacement of these factors and a creatinine of 1.2 or more for at least 2 days. The authors concluded that patients whose thromboplastin time and creatinine were in the possibly fatal range should be transferred to liver transplant centers for further evaluation and possible surgery. (87a)

A few patients with these criteria have been shown in other reviews to go on to semi-coma and even to coma and still survive. Bartels and Seeger, as early as 1977, presented 13 cases treated with charcoal hemoperfusion in the days prior to liver transplantation, who had encephalopathy grades II-IV. (56a) Ten of the 13 survived, but more importantly 3 of 5 patients with grade IV encephalopathy lived. Similar cases have been sporadically reported. (88,89)

A German group found that a quick thromboplastin time and a coagulation factor V under 10% of normal on admission were the best prognostic tests. Encephalopathy and renal failure were additional indicators, but not as good as the coagulation factors. The presence of either one was a very bad omen.