Fig. 1

Adult trauma patients who underwent PHEA in the East of England, 2015–2020. Study flow diagram. Cases excluded on interrogation based on mechanism of injury with n ≤ 10 are grouped to ‘Other’ to protect patient confidentiality and include: smoke inhalation, asphyxiation, electrocution, and hypothermia. ‘Training case’ refers to fictional patient record that was created for the purpose of training and education. PHEA prehospital emergency anaesthetic, RSI rapid sequence induction, SBP systolic blood pressure