Approaching Poisoning
5/11/10
PY Mindmaps
INITIAL ASSESSMENT
- resuscitation: airway protection, O2 and ventilation, fluid + vasoactives, give thiamine
- look for a particular syndrome on examination:
Anti-cholinergic
Opioid, sedative or ethanol
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delirium
tachycardia
dry and flushed skin
dilated pupils
myclonus
hyperthermia
urinary retention
bowel sounds
seizures
dysrhythmias
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anti-histamines
anti-parkinsonians
atropine
scopolamine
anti-spasmodics
mydriatics
skeletal muscle relaxants
many plants
Sympathomimetics
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delusions
paranoia
tachycardia
hypertension
hypotension (severe)
hyperthermia
sweating
piloerection
mydriasis
hyperreflexia
seizures
 cocaine
 amphetamines
 theophylline
coma
respiratory depression
miosis
hypotension
bradycardia
hypothermia
pulmonary oedema
decreased bowel sounds
hyporeflexia
seizures
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narcotics
barbiturates
benzodiazepines
ethanol
clonidine
Cholinergic
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confusion
CNS depression
weakness
salivation
urinary and faecal incontinence
GI cramping
vomiting
sweating
muscle faciculations
pulmonary oedema
miosis
brady or tachycardia
seizures
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organophosphates
carbamate insecticides
physostigmine
edrophonium
some mushrooms
Jeremy Fernando (2011)
INVESTIGATIONS
- CXR: aspiration/atelectasis
- SpO2: oxygenation
- Biochemisty: electrolytes, organ dysfunction, CK
- ABG: unexplained metabolic acidosis (an alcohol intoxification)
- Osmolar gap: useful in methanol or ethylene glycol poisoning
- Urine drug screen
- Serum testing: paracetamol, anticovulsants, salicylates, digoxin, ethanol, ethylene glycol,
methanol, iron, lithium, theophylline
MANAGEMENT
(1)
(2)
(3)
(4)
decreased drug absorption
increased drug excretion
antidote
manage complications
Decreasing Drug Absorption
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induced emesis: not to be encouraged c/o risk
gastric lavage: exact role uncertain (see Digestive Decontamination Document)
charcoal: 1gm/kg, given early, useful in some OD’s
whole bowel irrigation: polyethylene glycol, don’t give with charcoal, 1-4L/hr
Increase Drug Excretion
- forced alkaline diuresis: IV sodium bicarbonate until urinary pH > 7.5, consider in salicylate,
2,4-dichlorophenoxyacetic acid or mecoprop poisioning.
- multiple dose activated charcoal (‘gastrointestinal dialysis’): reabsorption of drug into GI
tract because concentration gradient lower c/o charcoal, consider in carbamazepine, dapsone,
phenobarbital, quinine or theophylline.
- haemodialysis: effective for low molecular weight drugs, consider in lithium, ethylene glycol
and salicylate poisoning
- haemoperfusion: passing patients blood into a device containing charcoal or absorbent
particles, useful in barbiturates, phenytoin and carbamazepine poisoning (anticonvulsants).
Anti-dotes
- see individual intoxifications and Antidotes Documents
Complications
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hypothermia: warm
hyperthermia: rare, consider infection, cool
seizures: treat cause and anti-seizure medication
rhabdomyolysis: check CK and manage accordingly
atelectasis and aspiration: protect airway, ventilate and CXR
Jeremy Fernando (2011)