October 29, 2008 (Chicago, Illinois) — Time on the scene of an accident or assault does not predict mortality in trauma patients taken to a level 1 trauma center, according to a retrospective observational cohort study. However, the results need to be validated, the researchers say. The study was presented here at the American College of Emergency Physicians (ACEP) 2008 Scientific Assembly.
Emergency medicine physicians have always believed that the “golden hour” of care was the most important factor for trauma-patient outcomes. “However, there are no real data to support this theory,” lead author Michael T. Cudnik, MD, associate professor in the Department of Emergency Medicine, Ohio State University Medical Center, in Columbus, told Medscape Emergency Medicine. “The data for this study was collected from the institution’s trauma registry.”
Dr. Cudnik and colleagues wanted to determine whether scene time had an effect on mortality in injured patients who were transported directly from the accident scene by ground or by air to a level 1 trauma center. This study took place between January 2001 and December 2006 in a large metropolitan area and included all patients aged 15 years or older who were admitted for at least 2 days or who died before 2 days. A total of 4461 patients were included in the analysis.
These patients had injuries from auto accidents, penetrating injuries, falls, or assaults. They were injured in their homes or in public places. Dr. Cudnik noted that the location of the injury was not accounted for in the analysis. Furthermore, although some of these patients might have had a myocardial infarction, such information was not obtained nor included in the analysis. The researchers did not include transferred trauma patients or patients arriving by private transportation.
A multivariate logistic regression analysis was developed for scene time and mortality to see if there was any association, and it adjusted for factors such as age, mode of transportation, and severity of injury. Injury severity score (ISS) and revised trauma score were obtained. Of the total patient group, 59% were transported by air. According to the study abstract, “the median ISS was 10, and overall mortality was 5.2%. Mean scene time did not differ between survivors (14.4 minutes) and nonsurvivors (15.3 minutes).”
In the final analysis, scene time was the only factor that had no association with mortality (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.96 – 1.01; P = .17). This lack of association remained when patients were stratified by those who had been intubated before arriving at the hospital (OR, 0.98; 95% CI, 0.94 – 1.02) and those who had not (OR, 0.99; 95% CI, 0.95 – 1.02).
Even for patients with a scene time longer than the mean, there was no “observable” increase in mortality (OR, 0.79; 95% CI, 0.51 – 1.22; P = .25). In addition, no increase in mortality was seen when patients were stratified by ground transport vs air transport, blunt vs penetrating trauma, Glasgow Coma Scale score less than 9 vs 9 or higher, and by those with an out-of-hospital systolic blood pressure of less than 90 mm Hg vs 90 mm Hg or more.
The researchers also looked to see whether scene time interval (in 10-minute increments) was found to be associated with an increase in mortality; it was not. The area under the receiver operating characteristic curve was 89.4.
“We can’t take the study on its face value [to determine whether] scene time is a predictor or not a predictor of mortality,” Brian O’Neil, MD, course director of the Research Forum at the meeting and associate chair of the Department of Emergency Medicine at Wayne State University School of Medicine in Detroit, Michigan, told Medscape Emergency Medicine.
“There are many factors that go into scene time that the study did not look at,” Dr. O’Neil pointed out. “Was the scene secure? Did the patient have to be extracted from the car? When it is possible to ‘scoop and run’ with patients, they do a little bit better.”
Nolan McMullin, MD, FACEP, a staff emergency physician at the Cleveland Clinic, in Ohio, who heard the presentation, said, “I find it a little surprising that scene time was not associated with a higher mortality. Throughout emergency medicine, we are taught how important it is to reach the medical center quickly.”
Dr. Cudnik did say that he would like to see future studies validate his findings. “It is important to identify which patients need to be transported quicker than others in order to save more lives.”
The study did not receive commercial support. Dr. Cudnik has disclosed no relevant financial relationships.
American College of Emergency Physicians (ACEP) 2008 Scientific Assembly: Abstract 171. Presented October 27, 2008.