PADIS and post mortem Flashcards
Difference of forensic and clinical toxicology
forensic = criminal or civil cases that testify in court
clinical = TDM testing done when TREATMENT neeeded
are lab techs regular or expert witnesses
regular
T/F Medical examiners must be a physician
T
T/F Coroners must be a physician
F - they do NOT have to be a physician except in Ontario
cause vs manner of death
cause - blunt trauma, opioid
manner - suicidal, accidental
what is the main cause of accidental deaths
opioid crisis
Common myth of overdose autopsy
overdoses do NOT show pill fragments - instead autospies rule our natural disease or truama
why do we use whole blood more than serum or plasma for autopsies
cells are hemolyzed after death
what are the fluid samples possible to get
blood - most abundant
vitreous humor - limited volume (3mL)
urine - not always available
injection site - NOT USEFUL as drugs are distrubted to all tissues
testing pro/cons for blood, vireous humor, and urine
blood- NOT good for biochemicals
vitrous humor - VERY good for alcohol and drugs
Urine- good for drugs
can you correlate drug [] in URINE with degree of impariment
NO
problems with liver sample lab testing post mortem
need to homogenize sample
high protein and lipid interferes
pros and cons of stomach sample
pro = interprets the TOTAL AMOUNT (not concentration) of drug
cons = presence of drug does NOT prove oral use
what is postmortem redistribution mechanism
-lungs and liver release drugs into blood after death
-pH decreases around lungs and liver
-basic drugs with >5L/kg will demonstrate the most redistribution
-cardiac increases redistribution
what causes delayed death
depressants (acetaminohen) with alcohols cause brain hypoxia
impaired metabolism for imiprimine (SSRI) enzyme
CYP2D6 and CYP3A4
what enzymes metabolize imiprimine
CYP2D6 - turns into hydroxyimprimaine CYP3A4 - turns into desparmine
Both switch enzymes to turn into hydroxydesimprimine
T/F you can detemine toxicity based off blood level values
F - tolerance exists
opiate vs opioid
opioid = activates mu-receptors of CNS
opiates = opium derived
what is a reversing agent for opioids
Narcan
how does narcan work
competetive antagoist binds to mu receptors = no activation
T/F repeated naloxone is needed for fent OD
T - halflife of fent is longer than naloxone
best way to administer naloxone
intravenous or intramuscular
oral is poor
what is one drug not reversed by nalaxone
benzodiazapines
what is the most common substance combined w fent that causes unintentional death
alcohol and fent
upcoming drug more potent than fent
nitazenes (20x stronger)
carfent (100x stronger)
limitation to cardiac glycosides or digoxin testing in GC/MS
immunoassay are not definitive
GC injection port breaks down digoxin
best testing for digoxin
LC/MS
can pancuronium and succinylcholine be tested using LC/MS/MS
pancuronium (Stable) can be tested
succinylcholine (unstable) cannot
can heavy metals undergo postmortem redistribution
yes - eg. cadmium
therfore we cannot use referene ranges postmortem
PADIS definition
poison and drug information services
role of PADIS
helpline for those who need information of substance ingestion or doctors call them for help aka toxocoviligance
what questions do PADIS ask?
- clinical status?
- what/when/how much did they take?
- physical exam
What is included in a tox workup
- tox panel for LACTATE
2.ECG - Chest Xray
T/F Urine is good for tox screen
F - immuno assay is not effective as they are just screening and has cross reactivities
does charcoal adsorb or absorb toxins
adsorbs
what are toxic drugs that cause hot and bothered symtpoms
- cocaine
- antidepressants
- ETC UNCOUPLERS (aspirin)
T/F - give tylenol for high temp
F - cool the body rapily with ice, or cooling/fanning
