The Stability of Blood Cholinesterase after Death

Abstract

Illness or death in a person who has recently used or had access to organophosphate insecticides—some of which are highly poisonous—may present a difficult problem in diagnosis. Post-mortem appearances are likely to be non-specific, and the gastric contents may not be helpful, especially if skin absorption or inhalation was the route of absorption. However, all organophosphate insecticides cause inactivation of the vital enzyme cholinesterase, which is present in the blood and tissues, and for which an accurate biochemical determination is possible. Is this inactivating effect on the enzyme persistent after death, or does the test become useless due to post-mortem changes? The investigation described in this report suggests that for at least one widely-used organophosphate, and probably for many others, the inactivation is persistent long after death, and that diagnosis of the probable cause of death may be possible for weeks afterwards, from the reduced enzyme content of the blood or tissues.