Bladder wash as an alternative biological matrix for postmortem toxicology: A critical mini-review

Abstract

Bladder wash has recently emerged as a potential alternative specimen in postmortem toxicology when urine is unavailable due to agonal bladder emptying, trauma, decomposition or other autopsy-related limitations. This critical mini-review evaluates the forensic relevance, analytical performance and practical limitations of bladder wash as a complementary matrix. A targeted literature review was conducted using PubMed, Scopus and ScienceDirect, focusing on peer-reviewed studies assessing bladder wash in postmortem toxicological investigations. Current evidence from more than 150 autopsy cases suggests that bladder wash provides high sensitivity for many non-volatile drugs and medications, with concordance rates close to those reported for urine when sensitive LC–MS-based methods are used. However, ethanol and volatile compounds are less reliably detected because of dilution effects. Bladder wash should therefore be considered a qualitative or semi-quantitative complementary matrix, not a substitute for blood or urine, but a useful tool to reduce false-negative investigations.