'Golden Hour,' CPR and the evolution of EMS
At no point during the period up to surgical intervention is time related to outcome, says study
By Art Hsieh
EMS1 Editorial Advisor
One medic remarked to me recently that things "really don't change" in EMS. But it's a risk to believe that our practice is stagnant — there's a need to stay current in the evolution of medicine.
In the past few days, there have been two articles that caught my eye that point to something old and something new that we might consider.
Nearly all of us have been steeped in the tradition of the "Golden Hour," the time frame that exists from the time a person is critically injured to the time they reach interventional care at a trauma.
The general concept basically says the greatest likelihood of survival from such an injury is highest when the time interval is less than 60 minutes. Dr. R. Adams Cowley, Professor of Thoracic Surgery and founder of the R Adams Cowley Shock Trauma Center in Baltimore, is generally credited with coining the term. He derived his supporting data in part due to French research conducted during World War I.
During the past decade, however, studies have shown that there may not be a relationship between time and survival rates. Just this past week, the results of a large-scale study by the Resuscitation Outcomes Consortium (ROC) were published. Its conclusion? At no point during the period up to surgical intervention is time related to outcome.
In the article, "Emergency Medical Services Intervals and Survival in Trauma: Assessment of the 'Golden Hour' in a North American Prospective Cohort" published in the March 2010 issue of Annals of Emergency Medicine(1), the authors report that dispatch time, on-scene time, and transport time had no relationship to how well the patient survived the injury. The journal's editor notes that the emphasis on time management might contribute to increased potential for a crash when transporting lights and siren. If so, it is possible that we could increase our safety without detriment to the traumatized patient.
One thing to keep in mind about this study — the researchers did not look directly at interventions done by the responders and how they affect the outcome. It would be interesting — and challenging — to study how BLS and ALS procedures might affect outcomes.
Another study provides further perspective on the developing "compressions-only" approach to layperson CPR technique. In the British medical journal Lancet this month, Japanese researchers published data that reinforces the notion that CPR with adequate ventilations is better for non-cardiac related cardiac arrest pediatric patients than just compression only.(2)
More importantly, the authors argue that training laypersons to just perform compressions in general may cause potential confusion and possible worse outcomes in this part of the pediatric population. They suggest that ventilations be taught to rescuers with the most contact with pediatric patients, such as teachers, parents and lifeguards.
An editorial comment made by researchers in Spain argues that a "double strategy" is confusing and suggests a training model that continues the current guidelines of ventilations and compressions, with the exception of compressions-only in adults suspected of having a cardiac-related cardiac arrest.
Confused? It's certainly easy enough. The lesson here is that even in current evolving medical practice, there are ongoing controversies and discussions. As prehospital care professionals, we owe it to our patients to make sure we stay on top of what’s happening in research that could affect the way we manage them.
1) Emergency Medical Services Intervals and Survival in Trauma: Assessment of the "Golden Hour" in a North American Prospective Cohort
2) Kitamura T, Iwani T, Kawamura T. Conventional and chest-compression-only cardiopulmonary resuscitation by bystanders for children who have out-of-hospital cardiac arrests: a prospective, nationwide, population-based cohort study. Lancet 2010; DOI:10.1016/S0140-6736(10)60064-5