Rethinking the Golden Hour of Trauma

Nearly all EMS providers can remember their first exposure to the concept of the Golden Hour—the idea that trauma patients have significantly better survival rates if they reach surgery within 60 minutes of their injury. But there is some question about where the Golden Hour originated and even more about whether it’s true.

In a 2001 literature review published in Academic Emergency Medicine, authors led by E. Brooke Lerner, PhD, attempted to determine the origin of the term.¹ They cited a series of studies discussing the Golden Hour, but found those studies often referenced one another and were not accompanied by supporting data or references to other studies. Most frequently the phrase is attributed to emergency medicine pioneer R Adams Cowley, who used it in 1973 in reference to helicopter transport of injured patients in Maryland.² Cowley observed that “care given in the first hour determines the extent of organ damage that the patient might sustain.” But Lerner and colleague Ronald Moscati were unable to find peer-reviewed studies to support the concept of the Golden Hour and attributed the idea to Dr. Cowley’s “experience and [the] opinion of one of the fathers of trauma surgery.”¹ However it began, the term entered the lexicon of emergency medical services and stuck.

A Recent Review

In March 2010, a study led by Craig Newgard, MD, and published in the Annals of Emergency Medicine attempted to discover a statistical link between the total “EMS interval” (or the time from 9-1-1 call until hospital arrival) and patient survival (see Table I).³ The authors included adult patients (15 or older) with traumatic injuries transported by EMS. The patients also met physiologic trauma criteria linked to “serious” injury (systolic blood pressure ≤ 90 mmHg, GCS ≤ 12, respiratory rate < 10 or > 29/min or placement of an advanced airway). Patients not transported directly to a trauma center from the scene were excluded, as were field deaths.

In addition to the total EMS interval, the authors evaluated the times tracked on a typical 9-1-1 call, including activation, response, scene and transport times. They also recorded information about each call (mechanism, type of injury, patient demographics) as well as treatments given and transport methods (ground vs. helicopter, ALS vs. BLS). The patient outcome tracked in the study was death within the hospital, either in the emergency department or after admission.

The study ultimately included 3,656 patients over 16 months. For these patients, the average total EMS time was 36.3 minutes. The authors were not able to find an increase in mortality for each additional minute of EMS time. They also analyzed the patient sample in 10-minute blocks and again found no link to mortality. Particular intervals like response and scene times (the “Platinum 10 Minutes”) also showed no association with worse outcomes. To answer the question of the Golden Hour, patients with total prehospital times of less than 60 minutes were analyzed separately from those with times of 60 minutes or more. Those with the longer times showed no association with increased mortality.

While this paper established no link between time and mortality, every study has limitations that may affect how useful its findings are. As an example, for this study injury severity (and therefore inclusion) was determined by field documentation. Since in-hospital injury severity was not available to the researchers, only patients who appeared injured to EMS personnel were included, rather than patients whose injury severity was determined based on their discharge diagnosis. Additionally, the study only measured in-hospital mortality and did not look at later deaths or how much function patients retained after discharge.

The authors drew their data from the Resuscitation Outcomes Consortium (a database containing patient information from 146 EMS agencies and 51 trauma centers in 10 regions of North America), which allowed them to increase their sample size and improve the data’s standardization. While use of this database resulted in more data points, it also introduced variation in EMS system design, patient and injury types and treatment protocols. For example, one region may have a trauma center far enough away that air ambulance use would be required to arrive in a timely manner, while another region may have multiple nearby trauma centers that would decrease transport times systemwide. The majority of the patients in Newgard’s study had total EMS times of less than the Golden Hour (average 36.3 minutes). The authors questioned if there were enough patients with total times greater than 60 minutes to adequately test the Golden Hour.

In Daily Practice

Cowley’s concept of the Golden Hour was based on the idea that the first hour of care determines the extent of organ damage.¹ This idea has grown into an imperative to get the patient to “definitive care” within an hour of their injury. The Annals study contradicts this concept but isn’t the only side of the story. Newgard and company referenced two Canadian studies that demonstrated a link between total prehospital time and mortality. Those studies have their own limitations.

For instance, their definition of a seriously injured patient was applied retrospectively (to patients already treated based on chart review) rather than prospectively (to future patients).³ Retrospective studies have the potential to introduce bias into selection of patients for analysis. This bias has the possibility of skewing results.

Like many treatments in medicine, the Golden Hour has evidence in support and opposition. In trauma patients, the focus on permissive hypotension in regards to fluid resuscitation represents a shift in traditional practice.⁴ This month’s CE article even discusses whether ALS treatment may be harmful to trauma patients. Rapid transport, like most treatments, is not without risk. Research has shown that the time saved by transporting with lights and siren does not provide “extra” time at the hospital for lifesaving treatments.⁵ At the same time, increased rates of crashes and fatalities are associated with emergency use.⁶ A recent review of news articles about ambulance crashes from traditional media found that in 80% of cases where response status was noted for a collision, the ambulance was operating with lights and/or sirens.⁷

Conclusion

Several studies have suggested a decrease in mortality when trauma patients reach definitive care during the Golden Hour, but recent research demonstrates no link between time and survival. The concept of the Golden Hour, though logical, appears to be the result of one man’s opinion and not the conclusion of a formal research study. Nonetheless, the term and the idea entered EMS and have been present since the early 1970s.

The pressure to arrive at the hospital within the Golden Hour may increase the number of emergent transports, which have been demonstrated to increase the risk for collisions resulting in injury and fatality. A review of the instructional guidelines for the EMT, AEMT and paramedic levels published by the National Highway Traffic Safety Administration indicates that the “golden period” is still listed as a guideline for teaching trauma care.⁸ Since recent evidence calls into question the concept of the Golden Hour, it may be time for EMS educators and system managers to rethink using the term in curricula and when designing systems of trauma care.

References

1. Lerner EB, Moscati RM. The golden hour: Scientific fact or medical “urban legend”? Acad Emerg Med 2001 Jul; 8(7): 758–60.

2. Cowley RA, Hudson F, Scanlan E, et al. An economical and proved helicopter program for transporting the emergency critically ill and injured patient in Maryland. J Trauma 1973; 13(12): 1,029–38.

3. Newgard CD, Schmicker RH, Hedges JR, et al. Emergency medical services intervals and survival in trauma: assessment of the “golden hour” in a North American prospective cohort. Ann Emerg Med 2010 Mar; 55(3): 235–246.

4. Morrison CA, Carrick MM, Norman MA, et al. Hypotensive resuscitation strategy reduces transfusion requirements and severe postoperative coagulopathy in trauma patients with hemorrhagic shock: preliminary results of randomized controlled trial. J Trauma 2011; 70(3): 652–62.

5. Marques-Baptista A, Ohman-Strickland P, Baldino KT, et al. Utilization of warning lights and siren based on hospital time-critical interventions. Preh Dis Med 2010; 25(4): 335–9.

6. Kahn CA, Pirrallo RG, Kuhn EM. Characteristics of fatal ambulance crashes in the United States: an 11-year retrospective analysis. Preh Emerg Care 2001; 5(3): 261–9.

7. Sanddal TL, Sanddal ND, Ward N, Stanley L. Ambulance crash characteristics in the U.S. defined by the popular press: a retrospective analysis. Emerg Med Intl 2010 (2010): E-published.

8. National Emergency Medical Services Education Standards: Paramedic Instructional Guidelines. National Highway Traffic Safety Administration, https://www.ems.gov/pdf/811077e.pdf.

Patrick Lickiss, BS, NREMT-P, is a paramedic for Alameda County (CA) EMS and blogs at 510Medic.com.