You are in charge of a busy evening shift, when the buzzer goes off in one of the resus bays. Your registrar has just administered IV ketamine for procedural sedation to suture a forehead laceration of a 4-year-old girl. The child vomited and was then noted to become red in the face with stridor and reducing O2 sats. She is now apnoeic and becoming bradycardic. Central pulse is still palpable.

1. List (4) possible causes for this episode 4 marks

2. State your immediate actions in a stepwise approach, including drug doses where appropriate 8 marks