|You are on call for the intensive care unit. A 13-year-old boy is referred to you by the on-call paediatric team. He and his parents are Jehovah’s Witnesses. He has a 10-day history of malaise, lethargy, intermittent headaches and leg weakness. In the last 24 hours, he has had weakness in all four limbs, difficulty with speech and drooling saliva out of the corner of his mouth.
Venous blood analysis: mild normocytic anaemia, low magnesium, high anion gap. Everything else is normal, including normal white blood cell count and erythrocyte sedimentation rate.
Arterial blood analysis: metabolically compensated respiratory acidosis, type 2 respiratory failure, glucose at the upper limit of normal, normal lactate.
Cerebrospinal fluid (CSF) analysis: high protein, no organisms seen, negative growth on CSF culture
1. Summarise the case.
2. What is your differential diagnosis?
3. Discuss the full blood count results.
4. Discuss the urea and electrolyte results.
5. What are the causes of low magnesium?
6. What is the anion gap?
7. What are the causes of a high anion gap?
8. Discuss the arterial blood gas results.
9. Discuss the CSF result. Why do you think the protein level is high?
10. What do you think is the most probable diagnosis?
11. What other tests would you carry out?
12. You are shown the patient’s chest X-ray and are asked to discuss it. What do you look for when assessing any chest X-ray?
13. Describe the pathology of Guillain–Barré syndrome and its clinical features.
14. Describe the pathology of myasthenia gravis (MG) and its clinical features.
15. How is MG diagnosed?
16. Describe the edrophonium test.
17. How would you manage the 13-year old boy described here?
18. How would you assess the need for invasive ventilation?
19. How would you intubate his trachea?
20. What drugs would you use?