From the Guidelines
Autopsy samples for microbiological analysis should be collected within 24 hours post-mortem, using scrupulous planning and strict aseptic technique to prevent contamination, with the subclavian vein being the most appropriate sampling site for peripheral blood. When collecting samples, it is essential to disinfect the skin or organ surface with alcohol-based solutions containing chlorhexidine or iodine, as described by 1. The following procedures should be followed:
- Peripheral blood should be collected from the subclavian vein, rather than the jugular or femoral veins, as stated in 1.
- Cardiac blood should only be collected when peripheral blood is not available, as noted in 1.
- Internal organs should be sampled while they are in situ, immediately after opening the body, and after appropriate anti-septic preparation or searing of the external surface of the organ, as recommended in 1.
- Separate sets of sterile instruments should be used to collect each sample, to avoid cross-contamination, as emphasized in 1.
- Bowel content samples, if collected, should be obtained last during evisceration, to prevent contamination of nearby organs by the gut microbiome, as advised in 1. Safety measures, such as ventilation, personal protective equipment, and immunization against hepatitis B virus, are also crucial to limit the risk of infection among staff working in the post mortem room, as discussed in 1.
From the Research
Standard Procedures for Collecting Autopsy Samples
The standard procedures for collecting autopsy samples for microbiological analysis involve various techniques and considerations to ensure accurate and reliable results. Some key points to consider include:
- The use of minimally invasive autopsy (MIA) procedures, which can provide valuable information on the cause of death while minimizing tissue damage 2, 3.
- The importance of careful evaluation of clinical history, macroscopic and microscopic findings, and laboratory results to interpret post-mortem microbiology results accurately 3, 4.
- The need for standardized sampling methods and protocols to ensure consistency and comparability of results 3.
- The potential for contamination during sampling procedures and post-mortem translocation, which can affect the accuracy of microbiological analyses 5.
Sampling Methods and Protocols
Different sampling methods and protocols may be used depending on the specific circumstances of the autopsy, such as:
- The use of post-mortem computed tomography (CT) and magnetic resonance imaging (MRI) to guide sampling procedures 3.
- The collection of samples from various tissues and fluids, including blood, cerebrospinal fluid, and organ tissues 2, 4.
- The use of molecular microbiology assays and culture-based methods to detect and identify microorganisms 2, 3.
Considerations for Interpretation of Results
When interpreting the results of microbiological analyses, it is essential to consider:
- The clinical history and antemortem information to provide context for the findings 4.
- The potential for contamination and post-mortem translocation, which can affect the accuracy of the results 5.
- The use of multiple lines of evidence, including laboratory, medical, and molecular findings, to support the interpretation of results 6.