Antibody mediated condition (of unknown origin) affecting postsynaptic nicotinic ACh receptor. Affects old men and young women.
Strong association with other autoimmune disorders.
Ptosis and diplopia occur early, muscle weakness and fatiguability are cardinal.
Beware bulbar symptoms!
- Involve neurologists early
- May benefit from immunomodulation (steroids, plasmapheresis, IV Ig)
- Continue oral pyridostigmine peri-operatively (or convert to IV neostigmine)
- A – Aspiration risk from bulbar palsy. Consider spraying cords to avoid use of NMBD
- B – Respiratory failure. Serial spirometry (typically restrictive picture)
- C – ?
- D – Consider TIVA. Avoid NMBD if possible, if neccessary 10-20% dose. Use sugammadex for reversal
- E – Maintain normothermia
- ICU back-up as may need post-op ventilatory support
- High risk = disease longstanding or severe e.g. high dose pyridostigmine, low vital capacity or bulbar involvement