Time is the enemy: Mortality in trauma patients with hemorrhage from torso injury occurs long before the "golden hour"

Abstract

Introduction: The concept of the "Golden Hour" has been a time-honored tenet of prehospital trauma care, despite a paucity of data to substantiate its validity. Non-compressible torso hemorrhage has been demonstrated to be a significant cause of mortality in both military and civilian settings. We sought to characterize the impact of prehospital time and torso injury severity on survival. Furthermore, we hypothesized that time would be a significant determinant of mortality in patients with higher Abbreviated Injury Scale (AIS) grades of torso injury (AIS ≥ 4) and field hypotension (prehospital SBP ≤ 110 mmHg) as these injuries are commonly associated with hemorrhage.

Methods: Data for this analysis was generated from a registry of 2,523,394 injured patients entered into the National Trauma Data Bank Research Data Set from 2012 to 2014. Patients with torso injury were identified utilizing Abbreviated Injury Scale (AIS) for body regions 4 (Thorax) and 5 (Abdomen). Specific inclusion criteria for this study included pre-hospital time, prehospital SBP ≤110 mmHg, torso injury qualified by AIS and mortality. Patients with non-survivable torso injury (AIS = 6), severe head injuries (AIS ≥ 3), no signs of life in the field (SBP = 0), interfacility transfers, or those with any missing data elements were excluded. This classification methodology identified a composite cohort of 42,135 adult patients for analysis.

Results: The overall mortality rate of the study population was 7.9% (3326/42,135); Torso AIS and prehospital time were noted to be strong independent predictors of patient mortality in all population strata of the analysis (P < 0.05). The data demonstrated a profound incremental increase in mortality in the early time course after injury associated with torso AIS ≥4.

Conclusion: In patients with high-grade torso injury, AIS grades ≥4, the degree anatomic disruption is associated with significant hemorrhage. In our study, a precipitous rise in patient mortality was exhibited in this high-grade injury group at prehospital times <30 min. Our data highlight the critical nature of prehospital time in patients with non-compressible torso hemorrhage. However, realizing that evacuation times ≤30 min may not be realistic, particularly in rural or austere environments, future efforts should be directed toward the development of therapies to increase the window of survival in the prehospital environment.

Keywords: Abdomen; Injury; Prehospital; Survival; Time; Trauma.