Table 1.

Descriptions, definitions, purposes, and aetiologies of cardiac arrest addressed for procedural milestones of EDT.

EDT Procedural Milestone	Description	Timing Definition	Critical purpose	Traumatic shock aetiology addressed
Right Chest Decompression	Insertion of decompressing tube into right pleural space or incision through right chest wall	Patient arrival to decompression of the right pleural space	Diagnosis and treatment of right pneumothorax or hemothorax Direct control of bleeding structures in the right chest	Right Tension Pneumothorax Right Tension Hemothorax Right Chest Bleeding
Retractor Deployment	Anterolateral incision of the left chest wall from skin to pleural space	Patient arrival to placement of chest wall retractor	Surgical exposure for subsequent milestones Diagnosis and treatment of left pneumothorax or hemothorax Direct control of bleeding structures in the left chest	Left Tension Pneumothorax Left Tension Hemothorax Left Chest Bleeding
Pericardiotomy	Opening of the pericardium, direct inspection of the heart	Patient arrival to delivery of the heart from the pericardial sac	Diagnosis and treatment of cardiac tamponade Diagnosis and treatment of cardiac injury Exposure for internal cardiac compressions	Cardiac Tamponade Cardiac Injury
Aortic Occlusion	Clamping of the descending thoracic aorta just above the diaphragm	Patient arrival to clamping of the descending aorta	Maximize perfusion of cerebral and coronary circulation by shunting available cardiac output Control of infradiaphragmatic hemorrhage	Abdominopelvic bleeding Lower extremity bleeding
Open Cardiac Massage	Open compression of the heart	Patient arrival to initiation of internal compressions	Provide cardiac output through manual compression of the non-beating heart	Cardiac failure