3. General approach
Resuscitate if needed
Risk assessment – is what they have taken dangerous?
Supportive Care and Monitoring
depending on your risk assessment
Investigations
Everyone:
Paracetamol level
ECG
Other as indicated
Decontamination – very rare
Antidotes
Enhanced elimination - rare
Seek and treat complications
Disposition – usually psych. Psych does the psych risk assessment for
us.
4. Toxinology
Critters rather than drugs/chemicals
We have one rare annoying, non-life threatening
spider in NZ.
Katipo = red back – painful bite and sweating +/-
back pain -> analgesia + antivenom.
Controversial whether antivenom actually works.
7. Toxidrome
Clinical toxicological syndrome
ie you can examine a patient +/- look at their ECG or
other bedside tests and get a good idea of what they
have taken
Eg
Opioid
Anticholinergic
Cholinergic syndrome
Serotonin syndrome
Na channel blockade
8. Toxidromes
Opioid: resp depression, decr LOC, miosis
Anticholinergic: hot as a hare, mad as a hatter, red as a beet,
dry as a bone eg datura
Cholinergic syndrome eg organophosphate, nerve gas
SLUDGEM: salivation, lacrimation, urinarination,
diarrhoea, GI upset, emesis, miosis + muscle spasm
Or DUMBELLS: diarrhoea, urination, miosis/muscle
weakness, bronchorrhoea/bradycardia, emesis,
lacrimation, salivation/sweating
Serotonin syndrome eg SSRI: sweating, agitation, increase
muscle tone, fever
Na channel blockade eg tricyclic: hypotension, decr LOC,
widened QRS
Rapidly alternating apnoea and coma eg GHB
9. Tox exam
HR
RR
Pupil size and reactivity and look for nystagmus
Armpits for sweat
Reflexes and test for clonus
Temp
ECG
BSL
Labs: almost everyone gets a paracetamol level
Cheap test. Treatment very efficacious.
11. Paracetamol/acetominphen
NB different units from UK
Common
Almost always reversible with antidote
High survival even from liver failure
How to you risk stratify and treat these ingestions?
What is the antidote?
12. Paracetamol/Acetominophen
Most common scenario: single ingestion, reasonable idea of time.
< 10g or 200mg/kg ingested within 8 hours does not need investigation
Otherwise or unknown:
< 2 hours post ingestion of non-liquid and cooperative patient ->
single dose activated charcoal.
< 4 hours post ingestion: wait and take blood for paracetamol level at
4 hours post ingestion. N-acetylcysteine (NAC) if over 1000µmol/L.
4-8 hours. Take level. NAC if over threshold on nomogram.
8-24 hours. Take level and start NAC. Stop treatment if under
treatment threshold.
24+ hours or unknown. Take level, VBG, LFT, glucose, INR, renal
function. Start NAC. Stop NAC if ALT normal. If liver failure d/w
liver unit
16. NAC
N-acetylcysteine
Very safe and effective
Boxes in ED with dose schedule written on them
3 different rates over 24 hours
Fairly frequent anaphylactoid reaction
Eg erythema, urticaria, pruritis, hypotension
Thought to be from histamine release rather than true
anaphylaxis
If mild reaction half rate +/- give IV antihistamine
If severe reaction. Stop infusion. Give IV antihistamine +/-
bronchodilators, fluids etc. Once asymptomatic for 1 hour
restart infusion at ¼ rate and titrate up
17. Disposition
In this hospital all patients requiring NAC get
admitted to ward under medical team.
Inform psych of admission. They say they will see
patient before “medically cleared”
20. Serotonin Syndrome
Rare
Excess serotonin usually from over dose of SSRI or
combination of serotonergic agents
Eg
SSRI, St John’s wort
Antipsychotics
Lithium
Pethidine
Tramadol
LSD
Ecstacy and other amphetamines
21. Serotonin Syndrome
Serotonergic drug +
Mild: Tremor, anxiety, nausea
Moderate: agitation and hyperreflexia and clonus
Severe: severe: fever, seizures, respiratory failure,
rhabdomyolysis, renal failure, DIC
25. CCB or Beta Blocker
Hypotension and bradycardia
Most beta blockers fairly benign
Exception: propranolol: Na channel blocking effect:
manage as for tricyclic + Beta blocker
Calcium channel blockers: nasty
Treatment?
26. Beta blocker + CCB
Resuscitate if required: ABCs
Risk assessment: look up to see how toxic the dose could be.
Supportive care and monitoring: if moderate risk: resus bay, IV
access, cardiac monitoring, IV fluids, trial of atropine, calcium
gluconate, pressors eg dopamine. If high risk likely to need
intubation
Investigations: ECG, paracetamol level, lactate, glucose.
Decontamination: Whole bowel irrigation likely to be needed
eg Polyethylene glycol via NG tube
27. Beta blocker + CCB
Antidote/specific treatments: could call calcium an
antidote to CCB, glucagon 5mg IV, high dose insulin 1
unit/kg then 1unit/kg/hour
Enhanced elimination: dialysis ineffective. Multidose
activated charcoal may be effective for CCB.
Seek and treat complications: Likely to need ICU
care. Monitor for MOF, rhabdo etc
28. If all of the above wasn’t working what else could be
done?
33. Iron
Can be life threatening and yet the patient is
asymptomatic, or has recovered
Look it up
Most accidental ingestions not harmful
Over a threshold ingestion -> iron levels useful
Low threshold for whole bowel irrigation
Antidote: desferoxamine
34. Digoxin
What are the 2 main types of toxicity?
What are the classic signs and symptoms?
What is the antidote?
35. Digoxin
2 main types of toxicity:
Acute ingestion – rare
Chronic – usually due to dehydration/renal impairment
Consider this in any patient on digoxin who is unwell. Check ECG, K+ and
digoxin level
Classic signs and symptoms
Yellowed vision
Nausea and vomiting
Confusion
Cardiac automaticity (ectopics or tachyarrythmia) and block
What is the antidote?
Digoxin FAB fragments – “digibind”
Expensive but cost effective
36. Indications for Digoxin FAB
Hemodynamically unstable or life-threatening
dysrhythmia,
Hyperkalemia > 6 mmol/L (6 mEq/L)
Plasma digoxin level > 20 nmol/L (15.6 ng/mL) at 6
hours post-ingestion
Digoxin level > 10 nmol/L (7.8 ng/mL) or elevated
digoxin level + renal impairment + symptoms in
chronic toxicity
41. Na channel blockade
"Prompt intubation, hyperventilation and
administration of administration of sodium
bicarbonate at the first evidence of severe toxicity is
life-saving"
45. Oral opioid toxicity
If significant respiratory/LOC depression usually
require naloxone infusion
Titrate IV nalaxone boluses to get just adequate
reversal – don’t make the patient withdraw and run
Infusion of 2/3 of reversal dose/hour
48. Neuroleptic malignant syndrome
Rare
Usually an idiosyncratic reaction to standard/high
doses of antispychotic rather than a result of
overdosage.
Life threatening
“Malignant Parkinson’s”
Parkinsonism + fever + autonomic instability
Doesn’t have the agitation, hyperreflexia or clonus of
serotonin syndrome
50. “My child might have taken some of granny’s
pills”
Try to work out what Granny is on
Default
Blood sugar
BP
ECG
If abnormal or toxidrome: IV line and treat empirically.
If normal: Observe 12 hours. Discharge if BP and BSL
normal
52. Flumazenil
Antidote to benzos
Almost never used
Only used if we caused the OD
For chronic benzo users or coingestion with a
proconvulsant (eg TCA) flumazenil may cause seizure
Benzos almost never need treatment or intubation
Recovery position, wait for them to wake up
53. Alcohol
Almost never needs intubation
Recovery position and observe
LOC should improve hourly – if not consider other
diagnosis eg head injury