Acute medicine Flashcards
Explain the CNS pathology of alcohol withdrawal (3 steps)
- GABA + alcohol causes increased CNS depression
- Chronic use causes upregulation of glutamate- enhances excitation
- Withdrawal reduces depressive effect of alcohol, causing excess CNS stimulation by unregulated glutamate.
Describe the symptoms of alcohol withdrawal after 6, 12, 36 and 48-72 hours
6 hrs: minor withdrawal: anxitety/ agitation, palpitations, GI upset, sweating + tremor.
12 hrs: Hallucinations: Visual/ tactile, normal mental status.
36 hrs: Seizures: short, generalised tonic-clonic seizures.
48-72 hrs: Delirium tremens: Fatal, delirium, severe tremor, fever, high BP and HR.
Give 2 differential diagnoses of delirium tremens.
Acute liver failure: AABB
- Ammonia: encephalopathy
- Albumin: ascites and peripheral oedema
- Bilirubin: jaundice
- Blood factors: bruising.
Wenicke’s encephalopathy: Vit B1/ thiamine deficiency: CAN
- Confusion
- Ataxia
- Nystagmus
Give 2 screening tools for alcohol-use disorder.
- CAGE: brief
- AUDIT: longer
Give 3 medications for the management of alcohol withdrawal.
- Benzodiazepines- chlordiazepoxide, diazepam
- Pabrinex: B vitamins to prevent Wernicke’s
- Glucose (if hypoglycaemic).
Glucose should only be given after pabrinex- glucose metabolism depletes vit B1
Give 3 common trigger types of anaphylaxis.
Give a risk factor for anaphylaxis.
Most common in children 0-4 years
- Food (children)- nuts
- Drugs: Penicillin, NSAIDs, latex, contrast agent
- Toxins: bee sting, venom
Risk factor: history of atopy.
Give 3 pathophysiological features of mast-cell/ basophil degranulation in anaphylaxis.
- Increased capillary permeability
- Bronchospasm
- Reduced vascular tone
Give the ABC presentation of anaphylaxis.
Give 2 skin/ mucosal changes in presentation of anaphylaxis.
Airway: throat swelling/ stridor
Breathing: increased RR, SOB.
Circulation: Shock- low BP, high HR, decreased consciousness.
- Urticaria and angioedema
- Flushing
Give two blood test findings in anaphylaxis.
Give the 6 steps in management of anaphylaxis.
- Raised serum tryptase and plasma histamine on blood test.
- Help
- Remove trigger
- Lie flat, raise legs
- IM adrenaline 0.5mg
- Airway, breathing, circulation
- IV chlorphenamine + IV hydrocortisone
What mass of aspirin per kg is an overdose and what mass per kg is a severe overdose?
- > 150mg/kg is OD, >500mg/kg is severe.
usually 300mg tablets
Give 4 early presentation signs of aspirin overdose.
Give 3 late presentation signs of aspirin overdose.
- Tinnitius, deafness, dizziness: “aspi-ringing”
- hyperpnoea- “rasp-irin” - direct stimulation of respiratory centre in medulla.
- Nausea and vomiting, diarrhoea, most poisoning.
- Hyperthermia/ sweating: “per-spirin-g”.
Low BP and heart block
Pulmonary oedema
Low GCS & seizures
What is first line investigation for aspirin overdose?
What results are found in this investigation in early and late salicylate poisoning?
Give 3 management steps for aspirin OD.
Early: respiratory alkalosis
Late: high anion gap metabolic acidosis.
Management:
- Activated charcoal- GI clearance
- IV sodium bicarbonate to treat urinary alkalisation
- Haemodialysis
What mass of paracetamol per kg is OD?
What is the pathophysiology of paracetamol OD?
- 150mg/kg. (500mg tablets)
- XS paracetamol metabolised by CYP450 in liver to NAPQI, which is conjugated with glutathione and excreted.
- Glutathione depleted, toxic NAPQI accumulates, hepatocyte necrosis.
Give features of paracetamol OD <24hrs, 24-72 hrs, >72 hrs.
- 24: mild N&V, lethargy
- 24-72: RUQ pain, vomiting, hepatomegaly
- > 72: acute liver failure.
What is the management of paracetamol overdose?
- N-acetyl-cysteine if below treatment line
- Liver transplant
