Bladder wash as an alternative urine specimen for postmortem toxicology

Abstract

Urine is the preferred sample in postmortem forensic toxicology to provide evidence of antemortem drug use. However, there are many scenarios in which the bladder is voided or dehydrated prior to their autopsy. In these cases, it is possible to wash the bladder with saline and collect the bladder wash and any residual urine for drug screening and confirmation. The San Francisco Office of the Chief Medical Examiner (OCME) has made the collection of bladder washes at autopsy an option, typically when urine is not available. While bladder washes are not conventional, this study aims to determine its use as an alternative specimen in postmortem forensic toxicology. Laboratory analysis of drugs by LC-MS/MS methodologies and alcohol by HS-GC-FID, was performed. Data from the analyses of bladder wash samples collected at the OCME were analyzed to assess the efficiency of this alternative sample in comparison to urine by determining the identities of individual analytes and their metabolites. Authentic case results showed that bladder wash drug analyses have good sensitivity and selectivity to serve as an alternative specimen when urine is not available. These results are even more so if both individual analytes and metabolites comparisons are considered during data analysis. The bladder wash drug analysis data was also compared to blood analysis data from the OCME to determine if the two were complementary. While bladder wash and blood drug analyses have compatible selectivities, the sensitivity of bladder wash analyses are lower than their blood counterparts. Crucially, in cases where only a bladder wash is analyzed, the detected drugs may provide critical information to a forensic pathologist about the cause and manner of death that would have otherwise not been obtained. Simultaneous to this study, a two-part survey was sent via the NAME list serve to evaluate pathologists’ views of the use of bladder washes before and after reviewing the results of the bladder wash data. This study appears to indicate that standardizing the collection and analysis of bladder washes in postmortem toxicology will provide forensic pathologists with a comprehensive toxicological profile in cases where urine and/or other biological specimens are not available for collection and subsequent analysis. Overall, pathologists were responsive to adopting the practice of collecting bladder washes for toxicological analysis. Bladder washes can serve as an efficient and accurate alternative specimen when there is no urine available to analyze. They are also a reliable alternative specimen to analyze when other specimens, such as blood and vitreous humor, cannot be collected and toxicologically analyzed.