Poisoning Flashcards
Name 5 medications with delayed reaction
Aspirin, paracetamol, iron, TCAs, co-phenotrope
When should O2 be given at the highest conc possibl?
In carbon monoxide poisoning and irritant gases
What happens if BP drops to below 70?
Irreversible brain damage, renal tubular necrosis
Which 3 classes of drug are more likely to cause cardiac conduction defects?
TCAs, antipsychotics, antihistamines
Management of hyperthermia
Remove all unnecessary clothing, fan, sponge with tepid water
What might cause hyperthermia?
CNS stimulants
Serotonin syndrome
Children taking antimuscarinics
What might cause hypothermia?
After deeply unconscious for hours
eg OD barbiturates or phenothiazines
(eg secobarbital or prochlorperazine)
Management of methaemoglobinaemia?
Methylthioninium chloride if hypoxic despite O2 or conc >30%
When is activated charcoal useful?
To prevent absorption if drug taken very recently (up to 1hr post ingestion)
To enhance elimination of drugs such as carbamazepine, dapsone, phenobarbital, quinine, theophylline
When should activated charcoal be avoided?
Petroleum distillates, corrosive substances, alcohols, malathion, cyanides and metal salts (including iron and lithium)
When is haemodialysis used in poisoning?
Ethylene glycol Lithium Methanol Phenobarbital Salicylates Sodium valproate
What is done in salicylate poisoning?
Activated charcoal if within 1hr and >125mg/kg ingested Haemodialysis considered (if>700mg/litre) Alkalinisation of urine (IV bicarbonate)
When is gastric lavage indicated?
Only in severe cases of poisoning where activated charcoal cannot be used
Iron and Lithium
What are the features of salicylate poisoning?
Hyperventilation (respiratory alkalosis) Followed by metabolic acidosis Tinnitus Deafness Vasodilation Sweating
When is salicylate poisoning severe?
> 500mg/L conc
Metabolic acidosis
When should activated charcoal be given in salicylate poisoning?
Within 1hr of ingesting >125mg/kg aspirin
Features of opioid OD
Coma, resp depression, pin point pupils,
Antidote to opioids?
Naloxone hydrochloride
IV infusion and monitoring
Danger of paracetamol OD?
Severe hepatocellular necrosis
Renal tubular necrosis
Liver damage maximal 3-4days post ingestion
Encephalopathy, haemorrhage, hypoglycaemia, cerebral oedema, death
Management of paracetamol poisoning
Hospital if >75mg/kg
Treat if >150mg/kg in less than 1hr
Acetyl cysteine protect liver if infused up to 24hrs post ingestion. Most effective for 8hrs post ingestion (augments glutathione levels)
When do you measure a paracetamol level?
4 hrs post ingestion
Use a graph w/the treatment line
Name 11 features of TCA OD
Dry mouth Coma & convulsions Hypotension Hypothermia Hyperreflexia Respiratory failure Conduction defects & arrhythmias Dilated pupils Urinary retention
Name 8 features of SSRI OD
Agitation Tremor Nystagmus Drowsiness Sinus tachycardia Convulsions n&v
What is serotonin syndrome?
Neuropsychiatric effects Neuromuscular hyperactivity Autonomic instability Hyperthermia Rhabdomyolysis Renal failure Coagulopathies
What is the antagonist to bezodiazepines?
Flumazenil
In massive beta blocker OD what is needed?
Atropine to treat bradycardia
IV glucagon if still in cardiogenic shock
If still, IV isoprenaline or pacemaker
Features of CCB OD
N+v+d
Agitation, confusion, coma
Metabolic acidosis and hyperglycaemia
Hypotension (cardiac depression)
Management of CCB OD
Activated charcoal within 1 hr
Calcium chloride/gluconate
Atropine
Management of iron OD
IV desferrioxamine mesilate (chelates iron)
Management of lithium OD
Haemodialysis
Increase urine output (fluids)
Supportive care (electrolytes, convulsions ec)
Gastric lavage?
Features of lithium OD
Apathy, restlessness
Ataxia, weakness, dysarthria, muscle twitching
Excess of 2mmol/L = poisoning
Stimulant OD?
Early stage (mania)-> lorazepam/diazepam Late stage (exhaustion hyperthermia)=> tepid sponging, anticonvulsants, ventilation
Effects of cocaine
Agitation, dilated pupils, tachycardia, hypertension, hallucinations, hyperthermia, hypertonia, and hyperreflexia; cardiac effects include chest pain, myocardial infarction, and arrhythmias.
Serious SE of ecstasy
Delirium, coma, convulsions, ventricular arrhythmias, hyperthermia, rhabdomyolysis, acute renal failure, acute hepatitis, disseminated intravascular coagulation, adult respiratory distress syndrome, hyperreflexia, hypotension and intracerebral haemorrhage
Self induced water intoxication
Management of theophylline OD
Repeated activated charcoal Ondansetron for vomiting KCl for hypokalaemia Lorazepam for convulsions Diazepam for sedation If not asthmatic: B-blocker
Management of cyanide poisoning
O2
Dicobalt edetate if strong clinical suspicion of severe cyanide poisoning
Hydroxocobalamin for smoke inhalation victims
Management of ethylene glycol or methanol OD
Fomepizole
Ethanol
Management of carbon monoxide poisoning
Clear airway 100% O2 NIV? Cerebral oedema-> mannitol ? hyperbaric O2 chamber
Management of organophosphate poisoning
Atropine
Pralidoxime chloride
