Porphyria Flashcards
1
Q
What is porphyria
A
Autosomal inherited group of disorders that are the result of various defects in haem synthesis.
Classification:
- Inducible forms
- Acute intermittent porphyria - Non-inducible forms
2
Q
How does acute intermittent porphyria manifest clinically
A
Neurological
- Anxiety
- Confusion
- Autonomic instability (HPT/tachycardia)
GIT
- Emesis
- Severe abdominal pain
3
Q
What can precipitate acute attacks of acute intermittent porphyria
A
Stress / fasting / dehydration / sepsis
Medications (many used in the perioperative period)
4
Q
Which commonly used perioperative agents are safe in acute intermittent porphyria and which are unsafe
A
SAFE
- Midazolam
- Cefazolin / Gentamicin / Co-amoxiclav
- Lidocaine
- Opioids (fentanyl and morphine)
- Propofol
- Succinylcholine
- Volatiles
- Non-depolarising muscle relaxants
- Paracetamol
- Dexamethasone
- Neostigmine
- Glycopyrrolate
- Ondansetron / Granisetron
- Bupivacaine
UNSAFE
- Thiopental
- Etomidate
- Ketamine
- NSAIDS (diclofenac)
- Alcohol
5
Q
What is acute intermittent porphyria
A
Inherited metabolic disorder caused by deficiency of porphobilinogen deaminase (enzyme found in the synthetic pathway of haem). Acute attack is likely fatal. Precipitants: stress, dehydration, infection, fasting, drugs.
