Poisoning

Question 1

what do we want to know from the history with regards to an overdose?

Answer 1

WHAT was taken-do they have the packet/container, AND was alcohol involved?
WHEN was it taken-exact timings, was it all at once?
WHY was it taken-accidental or intentional OD, was their suicidal intent-if so, assess for hopelessness and depression, was a suicide note left, have they tried before, will they try again?
HOW-ingestion, or IV, or inhalational
WHO-patient’s age, weight, PMH-liver or renal failure?, past psychiatric hx-diagnoses, medication, contact with a psychiatrist, social services, police, prev hospital admissions and prev self harming includ. suicide attempts.
WHAT ELSE-symptoms of OD, may be non-specific

Question 2

symptoms and signs of aspirin OD?

Answer 2

hyperventilation
tinnitus
deafness
vasodilatation
sweating
coma

Question 3

symptoms and signs of TCA OD?

Answer 3

both sympathetic and parasympathetic
CNS excitability, blurred vision, confusion, dry mouth, coma, seizures, arrhythmias, hypothermia, hypotension, tachycardia, pupil dilation, resp failure.
condition can rapidly change.

Question 4

symptoms and signs of BZD OD?

Answer 4

drowsiness
ataxia
nystagmus
dysarthria
resp depression
coma

Question 5

symptoms and signs of cocaine OD?

Answer 5

pupil dilation
tachycardia
chest pain
HTN
arrhythmias
MI
agitation
hallucinations
hyperthermia

Question 6

initial management of paracetamol OD?

Answer 6

general supportive care
bloods-FBC, U+Es, AST/ALT, clotting-INR/PT, arterial pH and lactate. serum paracetamol at 4h post ingestion.
consider activated charcoal if hepatotoxic dose (more than 75mg/kg) ingested in last HOUR
look up advice from National Posions service on TOXBASE/consult with medical toxicologist.

Question 7

paracetamol acute single ingestion OD management?

Answer 7

serum paracetamol 4h post ingestion plotted on nomogram-tx if level against time post ingestion gives value on or above the treatment line=IV N-acetylcysteine-increase hepatic availability of glutathione-antioxidant.
also start NAC immediately or empirically when:
pts present 8 or more hrs post ingestion
serum paracetamol level not available within 8hr time window
uncertainty as to timing of OD
pt unconscious or has suspected OD

if px 8 or more hrs post ingestion, started on NAC but serum paracetamol then comes back below treatment line then can stop NAC

Question 8

management of staggered paracetamol OD?

Answer 8

start IV NAC, and contact medical toxicologist
take bloods
can stop NAC if following criteria met as hepatoxicity very unlikely: more than 24hrs since last ingestion and all of:
paracetamol level less than 5mg/L
pt asymptomatic
INR 1.3 or less
ALT less than 2 times upper limit of normal
d/c patient and advise to return if become symptomatic e.g. vomiting, abdo pain.

Question 9

ADRs of N-acetylcysteine?

Answer 9

PO-nausea and vomiting
IV-anaphylactoid reaction, anaphylaxis and death
prev anaphylactic reaction NOT always a contraindication, can give antihistamine prophylaxis