Session 14 Flashcards
- Appreciate the range of poisons that can be taken / administered
- Recognise how unwell poisoned patients may present to hospital
- Have knowledge of the general management of patients with poisoning
- Know how paracetamol can cause hepatotoxicity
- Understand the importance of appropriate adoption of guidance in managing
- Understand how patient variability can impact on prescribing e.g. differing
- Appreciate the limits of clinical trials • Know the common causes of medication error
- Understand why elderly patients are more at risk of polypharmacy
- Learn how to minimise your future risk of prescribing errors
- Know the rules of prescribing
- Be able to identify medical errors on drug charts
- Appreciate how to prescribe drugs including antibiotics, insulin, warfarin, individual patients dose-response opiates and IV fluids.
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• Appreciate the range of poisons that can be taken / administered LO
How do you Classify drug poisoning?
Intended
• Alcohol
• Illicit drugs
• Deliberate self harm
Unintended
• Older people – iatrogenic (prescribed)
• Younger people - paracetamol
• Appreciate the range of poisons that can be taken / administered LO
Give examples of common UK poisons
- Paracetamol
- Hypnotics (diazepam, zoplicone)
- Salicylates
- Ecstasy
- Amitriptyline (tricyclic)
- Opiates
- Other anti-depressants
- Cocaine
• Recognise how unwell poisoned patients may present to hospital LO
- What clinical findings may a poisoned patient present with?
- Neurological signs poisoned patients may present with?
(• May be obvious • Might be concealed - do not want to tell you • Coma)
- • Alcohol/solvents on breath
• Needle track marks
• Blisters (barbiturates) - UMN signs (anti-cholinergics)
• Hypertonia
• Hyperreflexia
• Extensor plantars
Coma (many)
• Decerbrate/decorticate posturing
Dystonic (means: abnormal muscle tone -> muscle spasm and abnormal posture) movements (metoclopramide)
• Recognise how unwell poisoned patients may present to hospital LO
- What pupil signs might a poisoned patient present with? (state medical term)
What poisons can produce these signs?
Dilated pupils – ‘mydriasis’
• Anti-cholinergics (TCAs)
• Sympathomimetics (amphetamines)
• Blindness (quinine, ethanol)
Constricted pupils – ‘miosis’
• Opiates
• Nerve agents (e.g. VX)
• Recognise how unwell poisoned patients may present to hospital LO
- How may the ventilation of a patient who has been poisened change? State the poison which would cause these changes?
- How may blood gases change? State drugs which can cause this change?
- Hypoventilation
- Opiates
- Carbon monoxide poisoning
Hyperventilation
• Salicylates
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Acidosis
• Respiratory (hypoventilation)
• Metabolic (ethanol)
Alkalosis
• Respiratory (salicylates)
Hypokalaemia (β agonists)
Hyponatraemia (ecstasy)
Hypoglycaemia (insulin, alcohol)
Guess cause
Check pupils
If constricted - needle tract marks - opiates
Case History 2
- 82 year old female
- Thin and frail
- New confusion
- Disorientated in time, place and person
- Daughter available
Drug, sepsis, stroke, wide differential diagnosis
Normally on wide range of drugs
Difference in RR interval -> irregular
No p waves
Likely to be a fib
Then slurry st segment
T wave inversion - reversed tick
Renal failure
Evidence of hypokaleamia
Highly likely she is taking digoxin
Digoxin is removed through kidneys less removed so further effect
• Recognise how unwell poisoned patients may present to hospital LO
• Have knowledge of the general management of patients with poisoning LO
What drugs can be used as antidotes
Digibind - digoxin overdose
Flumazenil - barbiturates
Atropine - Organophosphate poisoning, Bradycardia secondary to drugs on the AV node:
• Know how paracetamol can cause hepatotoxicity
How is paracetamol normally metabolised?
How is paracetamol metabolised in an overdose?
- In substantial overdose, the conjugation of NAPQI is saturated leading to increasing toxic levels of NAPQI
- Therefore treatment is to replace Glutathione i.e. N-acetylcysteine (Parvolex)
What determines whether we give the patient who has overdosed with paracetomol charcoal/ n-acetylcysteine
If seen within 0-4hrs since overdose give activated charcoal orally
Blood test taken at 4hrs
Determine if they fail below(do not need treatment) or above they do need treatment