Interpretation of postmortem forensic toxicology results for injury prevention research

Abstract

Forensic toxicological data provides valuable insight into the potential contribution of alcohol and drugs to external-cause deaths. There is a paucity of material that guides injury researchers on the principles that need to be considered when examining the presence and contribution of alcohol and drugs to these deaths. This paper aims to describe and discuss strengths and limitations of postmortem forensic toxicology sample selection, variations in analytical capabilities and data interpretation for injury prevention research. Issues to be considered by injury researchers include: the circumstances surrounding death (including the medical and drug use history of the deceased person); time and relevant historical factors; postmortem changes (including redistribution and instability); laboratory practices; specimens used; drug concentration; and attribution of contribution to death. This paper describes the range of considerations for testing and interpreting postmortem forensic toxicology, particularly when determining impairment or toxicity as possible causal factors in injury deaths. By describing these considerations, this paper has application to decisions about study design and case inclusion in injury prevention research, and to the interpretation of research findings.

Poisoning of cats and dogs by the carbamate pesticides aldicarb and carbofuran

“…When one of these substances is found in the matrix, it is an indicative that the animal had contact with them (Harper et al, 1998). Another finding is that in some cases, we could detect more than one metabolite in the same animal by examining different matrices, which may be related to their stability and carcass distribution (Akcan et al, 2009;Baron and Merriam, 1988;Campelo and Caldas, 2010;Drummer et al, 2013;Risher et al, 1987;Skopp, 2010). In two cases, pesticides were detected in the vitreous humour, that is proven to be a reliable biological matrix for forensic purpose (Berkowicz et al, 2003;Guerrero et al, 2010;Thierauf et al, 2009).…”

“…In animals, necropsies are performed by veterinary pathologists or veterinarians, which should be made aware of the possible circumstances that lead to the death of the animals, and follow established protocols, both for the necropsy and samples collection for toxicology and histopathology. A toxicologist should always be consulted about the appropriate matrices according to the pathologist's suspicions, as well as the best methods of handling of the samples, in order to obtain consistent and reliable results (Byard and Boardman, 2011;Cooper and Cooper, 2008;Drummer et al, 2013;Flanagan et al, 2005;Munro, 1998;Wyman, 2012).…”

“…The accurate identification of possible toxic agents may take a long time. Because of the legal potential of the case, to ensure the reliability of the results, samples should be maintained under a rigorous chain of custody (de Zeeuw, 2004;Drummer et al, 2013;Skopp, 2010;Wyman, 2012). Toxicological analysis is necessary for the confirmation of substances such as aldicarb and carbofuran and their metabolites because of their similar gross appearance and necropsy findings.…”

Sedative and hypnotic drugs—Fatal and non-fatal reference blood concentrations

“…However, 21 such concentrations cannot directly be translated to a postmortem 22 setting [4][5][6][7]. Another problem is that compilations based on 23 postmortem data are a mix of literature reviews and case reports.…”

Intentional Carbofuran Poisoning in 7 dogs

“…In animals, necropsies are performed by veterinary pathologists or veterinary general practitioners, which should be made aware of the possible circumstances that lead to the carbofuranrelated death of the animals, and follow established protocols, both for the necropsy and sampling for toxicology. A toxicologist should always be consulted about the appropriate matrices according to the pathologist's suspicions, as well as the best methods for handling the samples, in order to obtain consistent and reliable results (6,8,12,14,25,43).…”