Nine hundred eleven patients with systolic blood pressures Although the total prehospital time was 35.8 + 10.4 minutes for MAST patients and 32.5 ± 10.7 minutes for No-MAST patients, 70% of patients with MAST had prehospital times greater than 30 minutes compared to 55% of the No-MAST patients. When the prehospital time was greater than 30 minutes, 31% of the MAST patients died, compared to 21% of the No-MAST patients. MAST application adversely affected the outcome most significantly for patients with cardiac and thoracic vascular injury. The overall mortality of 31% in the MAST group, compared to 25% in the No-MAST group was statistically significant (p = 0.05).