[Acute poisoning caused by methemoglobinemia-inducing substances. 6 cases].

Six patients were admitted to intensive care in Lodi Hospital with acute poisoning by substances causing methemoglobinaemia. They were treated with antidotes, purifying substances, blood exchange and symptomatic intensive care. The patients were observed 1-3 hours after ingestion of the poison. Three patients (50%) died. This is in line with reports in the literature given the severity of the poisoning. Three patients recovered completely and without sequelae. The importance of early diagnosis with particular attention to anamnestic data and the peculiar clinical symptoms of this syndrome is emphasised as essential for the prompt treatment required. A new classification for the causes of methemoglobinaemia based on pathogenetic criteria is proposed.