Low Down

  Many publications offer therapeutic, toxic and lethal ranges for a wide variety of poisonous substances, there is considerable variation in the quoted levels. These can be a source of confusion and sometimes dismay to the pathologist who, even with the advice of his local toxicologist, may find it difficult to decide whether a death can justifiably be attributed to a particular drug or other toxic substance. Even if he can so satisfy himself, he may be subjected to keen questioning, interrogation, doubt or criticism from colleagues, coroners, police, lawyers and others, who have access to different versions of toxic and fatal levels. The ultimate challenge may come in a criminal court, where opposing counsel may openly defy the pathologist's interpretations in cross-examination. There are some reasons for the variations found in such published data. He expresses the view that it is rather surprising that the order of disagreement is not greater, given the opportunities for dispar...

Many forensic situations involve drug abusers and persons with promiscuous sexual behaviour, where the statistical risk of HIV and hepatitis infection is markedly greater than in the general autopsy population. This poses a risk to pathologists, mortuary staff, police and laboratory staff who may deal with post-autopsy samples. All autopsies should be carried out with total precautions against infective risks, so that it does not matter what case is handled. However, this is almost impossible to achieve in a busy coroner or medical examiner practice and does not solve the problem of possibly infected material being sent out to other laboratories. A more common regime is to carry out pre-autopsy testing for HIV and hepatitis, using blood from a femoral needle puncture. The result can often be returned within hours, when a decision may be made as how to handle the autopsy - or even whether to abandon it, if the risk-benefit aspect is high. More usually, a positive result will result in t...