Flashcards in Poisoning & overdose Deck (54)
What is flumazenil
Precipiates withdrawal if dependent
Uses of flumazenil
May sometimes be used as an alternative to ventilation in children who are naive to benzo's or in COPD to avoid need for ventilation
What are the most important things to find out with OD/poisoning
Likely agents involved + coagents
Date and time of ingestion
Route of exposure
General examination of person who has ODed
Clinical signs of heroin OD
Reduced resp rate
Reduced level of consciousness
Delayed gastric emptying
Clinical signs of ecstasy OD
Signs of OD
Excessive cholinergic stimulation
Miosis, hypersalivation, vomiting, lacrymation, bradycardia
When are samples of ingested substance necessary?
If poisoning is suggested to be from:
• Ethylene glycol
• Iron salts
• Lithium salts
• Salicylates (aspirin)
Aims of effective management of poisoning
• Reduce absorption (activated charcoal if within 1 hr, whole bowel irrigation if drug smugglers)
• Give an antidote
• Increase elimination (multiple dose activated charcoal if drug undergoes enterohepatic circulation, urine alkylation for salicylates, dialysis)
What is activated charcoal ineffective for?
Alcohol + ionised drugs
What is used in paracetamol poisoning?
What is atropine used for?
Treatment of cholinergic excess (malathion poisoning)
To block PNS action of bradycardia (ß-blockers, digoxin)
What is used to treat iron poisoning
How do you treat digoxin toxicity?
Using digoxin-specific antibdy fragments (Fab fragments)
Bind to digoxin, blocking uptake-> renal excretion
Use of fomepizole
Used to manage methanol and ethylene glycol poisoning
Blocks alcohol dehydrogenase, limiting toxic metabolites
Management of warfarin poisoning
Vitamin K (Phytomenadione)
What is used in ß-blocker toxicity
How much paracetamol can cause liver toxicity?
As little as 7g
When do you measure plasma-paracetamol level?
4-15hrs after ingestion
What factors are associated with a poor prognosis after paracetamol ingestion?
Prolonged prothrombin time
Low blood pH
When does maximal liver damage occur in an untreated paracetamol OD patient?
72-96hrs post ingestion
Pathophysiology of paracetamol liver damage
Metabolism pathways become oversaturated, build up of free radicals
Free radicals cause liver damage
When should acetyl-cysteine be administered?
Within 10hrs of ingestion
Only after plasma levels are known (treatment line) (unless late presenation or staggered OD
Course of 21hrs infusion
Action of N-acetyl cysteine
Replenishes stores of glutathione
What happens if Acetylcyteine gives rash/bronchospasm
Give antihitamine and bronchodilator
Symptoms of iron overdose
N+V + diarrhoea
Management of iron OD
Admit if >20mg elemental iron/kg
Gastric lavage/aspiration if<1hr post ingestion
Take serum iron level
ABGs, LFTs, Abdo Xray (radio opaque)
Management of opioid OD
Signs of salicylate poisoning