Viva 4

You are asked to assess a 54 year old man scheduled for an urgent laparotomy for a suspected perforated duodenal ulcer.  He has recently developed symptoms of double vision, ptosis, dysarthria and generalised muscle weakness.  He was due to be reviewed by a neurologist next week.  The anaesthetist asks for a post-op bed in ICU.  The patient  has a 25-pack year history of smoking but ceased smoking 3 months ago. What are your differential diagnoses for his weakness?

Focus of discussion- Approach to neuromuscular weakness, clinical and lab testing, assessment of suitability for extubation

Disclaimer: the viva stem above may be an original CICM stem, acquired from their publicly available past papers. Or, perhaps it is a slightly altered version of the original CICM stem. Or, it is a completely original viva stem, concocted by the monstrously amoral author of Deranged Physiology for nothing more than his own personal amusement. In either case, because the college do not make the main viva text or marking criteria available, almost everything here has been confabulated. It might sound like a plausible viva and it could be used for the purpose of practice, but all should be aware that it does not represent the "true" canonical CICM viva station.