Fig. 1

Study flow diagram of patients attended by EAAA who underwent arterial catheterisation and initiation of IABP monitoring; 01/02/2015-20/04/2023. EAAA = East Anglian Air Ambulance; IABP = intra-arterial blood pressure. *Cases were manually reviewed if there were less than 10 min of IABP measurements recorded, or all systolic IABP measurements were less than 90mmHg, or all mean arterial pressures on IABP were less than 50mmHg