44 Questions
What is the main focus of forensic toxicology?
Investigating cause and manner of death in postmortem cases
In which type of cases does forensic toxicology play a significant role?
Impaired driving and drug facilitated assault
What distinguishes an expert witness in court from a regular witness?
An expert witness provides opinion evidence based on education, training, and experience
What type of testing is typically done in clinical forensic toxicology?
(GC/MS(/MS) LC/MS(/MS)
What is the medical use of fentanyl in acute surgical procedures?
Induction of anesthesia
Which benzodiazepine increases CNS depression and is not reversed by naloxone?
Etizolam
What is the role of naloxone in reversing opioid overdose for highly tolerant abusers using high doses?
Higher doses of naloxone are required to reverse a coma
What is the primary concern with some newer opioids according to the text?
Users are not familiar with the 'right' dose and potency of the specific batch being trafficked
Which type of sample is most commonly used in forensic toxicology testing?
Whole blood
What is the main purpose of sample processing and extraction in forensic testing?
Minimize interference and concentrate the analyte for improved sensitivity
Which immunoassay design is optimized for diluted whole blood in forensic work?
ELISA plates
What are common extraction methods for GC-based assays?
Liquid-liquid and solid-phase extractions
What process aims to make the analyte more soluble in a solvent than the aqueous specimen?
Extraction process
What influences the extraction scheme used in forensic testing?
All of the above
Which techniques are employed to prepare samples for specific analytical methods?
Dilution, headspace analysis, and protein 'crash'
What does the extraction process involve in whole blood samples?
Denaturing proteins and peptides in whole blood
Which factors influence the extraction process in forensic testing?
Both a and b
Which sample is useful for alcohol analysis and some drugs?
Vitreous humor
Which system in Canada conducts death investigations in Alberta, Manitoba, Nova Scotia, and Newfoundland?
Chief Medical Examiner system
Where is the Alberta Office of the Chief Medical Examiner located?
Edmonton
What is the most consistently available sample used for toxicology?
Whole blood
Which forensic laboratories in Canada focus on criminal cases?
RCMP labs in Vancouver, Edmonton, and Ottawa
Which sample provides a large amount of specimen for drug analysis?
Liver samples
Who determines the cause and manner of death in the Medical Examiner system?
Forensic pathologist
What is the myth about all drug overdoses according to postmortem toxicology?
All drug overdoses leave evidence in the stomach.
What role does postmortem toxicology play?
Determining cause and contributing factors of death.
Which sample can show fluctuating drug concentrations after death?
Vitreous humor
What should stomach contents be interpreted based on?
Total amount of drugs present.
What are synthetic cannabinoids also known as?
Spice and K2
How do synthetic cannabinoids interact with the body?
By interacting with cannabinoid receptors
Why is analyzing synthetic cannabinoids challenging?
Due to low blood concentrations and over 200 possible structures
What risks do users face with synthetic cannabinoids?
Unpredictable toxicity and long-term effects due to varying composition and potency
What is the difference between opioids and opiates?
"Opioids refer to any chemical that activates mu-receptors, while opiates are naturally occurring or semi-synthetic derivatives of the opium poppy"
What does opioid tolerance allow individuals to do?
"Withstand increasing doses with static or decreasing side effects"
What is naloxone's function as a reversing agent for opioid overdose?
It competitively binds to mu-receptors, displacing opioids without activating the receptors.
Why is repeat naloxone injection and close monitoring necessary when dealing with fentanyl overdose?
Fentanyl's half-life is longer than naloxone's half-life.
In what ways can medical administration of naloxone be carried out?
Intravenous, intramuscular, or intra-nasal
What makes overdose reversal more challenging for certain opioids?
They may be tolerant to naloxone.
What is postmortem toxicology primarily concerned with?
Analyzing bodily fluids and tissues for drugs or toxins after death
Which of the following is a specimen commonly analyzed in postmortem toxicology?
CSF
Why is chain of custody crucial in postmortem toxicology?
To track exhibits from collection to disposal and ensure the integrity of analysis
How can carbon monoxide cause deaths?
Through its strong binding to hemoglobin
Why is postmortem blood on its own unreliable for assessing alcohol presence at the time of death?
Due to fermentation, which can lead to false high BAC levels
What factors contribute to postmortem redistribution of drugs in the body?
$pH$ changes and weakening of protein binding
Study Notes
Postmortem Toxicology and Forensic Science
- Postmortem toxicology involves analyzing various bodily fluids and tissues to determine the presence of drugs or toxins after death.
- Specimens for analysis can include gastric fluid, bile, CSF, lungs, kidneys, and injection sites, among others.
- Chain of custody is crucial in postmortem toxicology to track exhibits from collection to disposal and ensure the integrity of analysis.
- Carbon monoxide can cause deaths through its strong binding to hemoglobin, and it can be found in various sources, including less obvious ones.
- Postmortem toxicology differs from antemortem toxicology due to factors such as postmortem fermentation and redistribution of drugs in the body.
- Postmortem blood on its own is unreliable for assessing alcohol presence at the time of death due to fermentation, which can lead to false high BAC levels.
- Postmortem redistribution of drugs occurs as cells die, pH changes, and protein binding weakens, potentially leading to significantly increased drug concentrations in certain tissues.
- Delayed deaths involving depressants or alcohol can result in low or near-absent drug levels, making it challenging to determine the cause of death through toxicology.
- Postmortem THC analysis is complex, involving factors such as redistribution, concentration in muscle tissue, and the presence of fat in postmortem blood.
- Postmortem THC concentrations can be significantly higher than antemortem concentrations, leading to challenges in interpreting the influence of THC on certain deaths.
- Postmortem toxicology case examples illustrate the complexities of interpreting postmortem blood concentrations of THC in different scenarios.
- Postmortem blood samples are not always reliable due to factors such as contamination and the fat solubility of THC.
Test your knowledge of postmortem toxicology and forensic science with this quiz. Explore topics such as specimen analysis, chain of custody, carbon monoxide poisoning, postmortem drug redistribution, and the complexities of postmortem THC analysis.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
