Background: Rapid vascular access is essential for haemorrhage resuscitation in major trauma. Pathways for inadequate vascular access are less defined. We investigated access escalation, triggers and mortality in severely injured trauma patients. Methods: Patients were identified from the Royal Perth Hospital trauma registry, and a retrospective review was performed of those requiring vascular access during prehospital or ED resuscitation from January-December 2024. Variables included demographics, injury severity score (ISS), cardiac arrest, access type, massive transfusion protocol (MTP) activation and mortality. IO/CVC escalation was defined as intraosseous access, central venous catheter, MAC line or large sheath. Escalation trigger was MTP activation and/or cardiac arrest. Fisher’s exact and Mann-Whitney U tests were used. Results: Thirty-eight eligible patients were identified. Median age 45.5 years, 68.4% male, median ISS 26. Cardiac arrest occurred in 8/38 (21.1%), MTP was activated in 14/37 (37.8%), in-hospital mortality was 10/38 (26.3%) and 24-hour mortality was 8/38 (21.1%). Prehospital PIVC was documented or attempted in 32/38 (84.2%), prehospital IO was used in 2/38 (5.3%). In ED, PIVC was documented in 24/38 (63.2%), IO in 2/38 (5.3%), and CVC/MAC/large sheath in 7/38 (18.4%). IO/CVC escalation occurred in 9/38 (23.7%). All escalations occurred in patients with MTP activation and/or cardiac arrest (9/18 vs 0/20, p<0.001), but only half of trigger-positive patients were escalated. Escalation was more common with MTP activation (6/14 vs 2/23, p=0.035). All cardiac arrest patients died in hospital (8/8 vs 2/30, p<0.001), while ISS did not differ by survival. Conclusion: Mortality clustered around physiological collapse rather than ISS, yet escalation beyond PIVC occurred in only half of patients with MTP activation and/or cardiac arrest. These findings support a structured circulation-access algorithm for major trauma.