Acute medicine Flashcards
(30 cards)
What is alcohol use disorder?
When a person continues to drink even though it is harmful and leads to physical health problems
What is alcohol dependence?
When a person has CRAVINGS for alcohol and has developed a TOLERANCE to it (needs more alcohol to have the same effect)
What is alcohol withdrawal?
Physical and psychological symptoms associated with sudden decrease in alcohol consumption
What is the pathophysiology of alcohol withdrawal?
GABA – inhibitory neurotransmitter
Glutamate – excitatory neurotransmitter
Alcohol is a GABA receptor agonist
Over time with chronic alcohol use:
- upregulation of glutamate receptors (compensatory mechanism)
So when you don’t take alcohol, there isn’t that CNS depressant effect to cancel out the upregulated CNS stimulatory effect →
excessive CNS stimulation → WITHDRAWAL SYMPTOMS
What is the presentation of alcohol withdrawal?
CNS overactivity → symptoms
Day 1:
MILD SYMPATHETIC AROUSAL Minor withdrawal - approx. 6 hrs after you stop drinking: - anxiety/agitation - palpitations - nausea & vomiting - sweating + tremor
MIND BECOMES OVERACTIVE
Hallucinations - approx. 12 hrs:
- visual/tactile hallucinations
- normal mental status
Day 2:
BODY BECOMES OVERACTIVE
Seizures - approx. 36 hrs:
- short, generalised tonic-clonic seizures
Day 3:
SYSTEMIC OVERACTIVITY Delirium tremens - 48-72 hours (FATAL): - delirium - severe tremor - fever - high BP + HR
What are the differential diagnoses of delirium tremens?
Acute liver failure:
- ↑ Ammonia → ENCEPHALOPATHY
- ↓ Albumin → ascites and peripheral oedema
- ↑ Bilirubin → jaundice
- ↓ Blood factors → bruising
(encephalopathy can cause delirium tremens like symptoms)
Wernicke’s encephalopathy:
- Confusion
- Ataxia
- Nystagmus
What would you include in the history and examination if you were suspecting alcohol withdrawal?
HISTORY:
Screen for alcohol-use disorder:
- Brief CAGE questionnaire
- Longer AUDIT questionnaire
Severity of withdrawal:
- CIWA-Ar scale (Clinical Institute Withdrawal Assessment from Alcohol Revised scale)
EXAMINATION (abdo):
- Signs of alcohol abuse (chronic liver disease)
What investigations would you do if you were suspecting alcohol withdrawal?
Bedside:
- Observations (tachycardia, temperature)
Bloods (to rule out differentials):
- FBC
- U&Es
- LFTs, INR
- Glucose
Differentials:
- Hypoglycaemia
- Electrolyte abnormalities
- Hepatic encephalopathy
How would you manage alcohol withdrawal?
- Benzodiazepines (chlordiazepoxide, diazepam)
- Pabrinex (B vitamins - contains B1) to prevent Wernicke’s
- Glucose (if hypoglycaemic)
- Manage alcohol dependence:
- drug and Alcohol Liaison Specialist (DALS)
- community services (e.g alcoholics anonymous)
- therapy
Define anaphylaxis
A life-threatening, systemic, hypersensitivity reaction
- characterised by airway +/- breathing +/- circulation problems
- usually associated with skin/mucosal changes
What is the epidemiology of anaphylaxis?
Most common in children 0-4 yrs
What is the aetiology and risk factors of anaphylaxis?
3 common triggers:
- food (children) - e.g. nuts
- drugs/chemicals (adults) - e.g. penicillin, NSAIDs, latex, contrast agent
- toxins - e.g. bee/wasp sting, venom
Risk factor:
- history of atopy (hay fever, eczema, asthma)
What is the pathophysiology of anaphylaxis?
Main mechanism (type 1 hypersenstivity):
1) Sensitisation
→ immune system recognises substance (e.g. peanut)
→ triggers IgE production (abnormal)
→ IgE becomes bound to the surface of mast cells and basophils
2) Repeat exposure
→ IgE already bound the mast cells and basophils bind to the antigen (i.e. from the peanut)
→ degranulation and release of histamine into the bloodstream
→ systemic effects - ANAPHYLAXIS
Main effects of histamine: - vasodilation - increased capillary permeability - bronchoconstriction (responsible for presentation)
What is the presentation of anaphylaxis?
ABC + skin/mucosal
Airway:
- throat/tongue swelling
- stridor
Breathing:
- SOB
- increased RR
- decreased O2
Circulation:
- SHOCK → low BP, high HR, decreased consciousness
Skin/Mucosal:
- urticaria and angioedema
- flushing
What investigations would you do if you suspect anaphylaxis and what would you expect to see?
If diagnosis in uncertain, you can do blood tests:
- ↑ serum tryptase
- ↑ plasma histamine
How would you manage anaphylaxis?
1) Call for help
2) Remove trigger (allergen)
3) Lie patient flat and raise legs
4) IM adrenaline 0.5mg 1:1000
5) Manage airways, breathing, circulation
6) IV chlorphenamine + IV hydrocortisone
Follow up:
- Refer to allergy/immunology clinic
- RAST specific IgE testing to determine allergies
- Provide Epipen and education re anaphylaxis
- Medic Alert bracelet
What is poisoning?
Administration of excess pharmaceutical agent
What is the epidemiology of poisoning?
Accidental poisoning in children < 10yrs
Deliberate poisoning > 10yrs, usually 15-35yrs, often associated with alcohol use
What investigations would you do if you suspected poisoning?
- ABCDE assessment
- ECG
- FBC, U&E, LFT, INR, glucose
- Paracetamol and Salicylate levels
- ABG
How would you manage poisoning?
TOXBASE provides information on dealing with various poisons
National Poisons Information Service (NPIS) helpline
Consider activated charcoal if <4h
(reduces absorption of drug)
Consider gastric lavage (rare)
What is aspirin overdose defined as?
Overdose if > 150mg/kg
Severe if >500mg/kg
What is the presentation of aspirin overdose?
Early presentation:
- tinnitus, deafness, dizziness (aspiringing)
- hyperpnoea (raspirin)
- hyperthermia, sweating (perspirin)
- N&V, diarrhoea
Late/severe presentation:
- low BP and heart block
- pulmonary oedema
- low GCS + seizures
What are the laboratory findings of aspirin overdose?
Early:
respiratory alkalosis
Intermediate:
mixed respiratory alkalosis and metabolic acidosis
Late:
high anion gap metabolic acidosis
What is the management of aspirin overdose?
Urine alkalinisation with IV sodium bicarbonate
Dialysis
