Using Mechanism of Injury In Your Trauma Activation Criteria
The Centers for Disease Control and Prevention (CDC) published a set of Guidelines for Field Triage two years ago. Click here to download them. They list 4 tiers of activation criteria to help prehospital providers triage patients appropriately to trauma centers.
Tier 1, which are physiologic criteria, and Tier 2 (anatomic criteria) are very accurate in predicting injury serious enough to require trauma team activation. Tier 3 contains mechanism criteria, and many centers who use these verbatim in their activation criteria end up with a fair amount of overtriage. Some centers even see a significant number of patients who meet Tier 3 criteria go home from the ED!
The Yale department of Emergency Medicine looked at intrusion into vehicle criteria (more than 12” near an occupant, more than 18” anywhere on the vehicle) to see if they are a valid predictor for admission or trauma center transport. It was a retrospective review of EMS transports to the Yale ED or to one satellite site.
Unfortunately, the number of vehicles that met intrusion criteria (48) was small compared to the number without significant intrusion (560). This makes the data a little less convincing than it may have been. The likelihood that intrusion would require trauma center admission (Positive Predictive Value) was only 26%. The likelihood that trauma center resources would be utilized (for issues like death, ICU stay, operation, spinal injury or intracranial hemorrhage) was only 13%. The authors recommend that the CDC guidelines be tweaked based on this data.
Bottom line: I think the numbers are far too small to convince the CDC to change their guidelines. But I would urge each trauma center that uses the intrusion criteria for activation to carefully study how many of those patients have minor injuries or go home from the emergency department. They may find that they can rely on other more accurate criteria and decrease their overtriage rate at the same time.
Reference: Motor vehicle intrusion alone does not predict trauma center admission or use of trauma center resources. Prehospital Emerg Care 15:203-207, 2011.
Helicopter EMS: The Risks
Yesterday, I wrote about the (unclear) benefits of helicopter EMS transports. Today, I’ll cover the risks. The number of medical helicopters in the US has grown dramatically since 2002.
As can be expected, the number of mishaps should go up as well.
Although it looks like the fatal and injury accidents peaked and then declined, it does not look as good when compared to the rest of the aviation industry. Consequently, being on a helicopter EMS (HEMS) crew has become one of the more dangerous professions.
And unfortunately, the numbers have not improved much during the past five years. So what to do? Make it a big PI project. Approach it systematically, analyze the issues, and create some guidelines and protocols for all to follow.
Tomorrow, I’ll review new guidelines for HEMS released by the American College of Surgeons Committee on Trauma.
Reference: Medical helicopter accidents in the United States: a 10 year review. J Trauma 56:1325-1329, 2004.
Helicopter EMS: The Benefits?
The use of medical helicopters has grown at an astonishing rate in the 10+ years since Medicare got involved with payment for this service. All high level trauma centers have helicopter landing facilities, and many either own or are a part owner in at least one helicopter EMS service (HEMS).
Here’s a state by state breakdown of the number of medical helicopters:
It’s gotten to the point where the indication for summoning a HEMS service seems to be the presence of a patient to ride on it!
A lot of papers have been published in the past 20 years trying to justify the benefits of using these services. As is the usually case when a lot of papers are published on one subject, most of them are not very good. Lots of studies have been performed to try to justify their use, and most were not successful. The following items have been scrutinized:
- Interfacility transfers
- Pediatric transfers
- Pediatric trauma
- Rural trauma
Most of these papers found little, if any, benefit. The ones that did tended to be published by institutions that owned these services, raising the question of bias. The one thing that was always significantly different was the cost. HEMS costs at least 10 times more that ground EMS transport.
So the benefits are not very clear. What about the risks? I’ll talk about those tomorrow.
Click here to view the interactive state map of medical helicopters. See where your state is with respect to number of ships and services, and how busy they are.
Scoop and Run or Stay and Play for Trauma Care?
Scoop and run vs stay and play are traditionally EMS concepts. Do I stay at the scene to perform invasive procedures, or do I perform the minimum I can and get to the nearest hospital?
For trauma patients time is the enemy and there is a different flavor of scoop and run vs stay and play. Do I take the patient to a nearby hospital that is not a high level trauma center to stay and play, or do I scoop and run to the nearest Level I or II center?
Admissions to a group of 8 trauma centers were analyzed over a 3 year period. A total of 1112 patients were studied. Patients were divided into two groups: those who were taken directly to a Level I trauma center (76%), and those who were transferred from another hospital (24%).
Patients who were taken to a non-trauma center first received 3 times more IV crystalloid, 12 times more blood, and were nearly 4 times more likely to die!
Obviously, the cause of this increased mortality cannot be determined from the data. The authors speculate that patients may undergo more aggressive resuscitation with crystalloid and blood at the outside hospital making them look better than they really are, and then they die. Alternatively, they may have been under-resuscitated at the outside hospital, making it more difficult to ensure survival at the trauma center.
Bottom line: this is an interesting paper, but there are a number of flaws that prevent us from mandating that all trauma patients should go directly to the trauma center. The authors never really define a “nontrauma hospital.” Does a Level III or IV center count? How did patients who stayed at the outside hospital do?
A lot of work needs to be done to add detail to this work. In the meantime, we have to trust our experienced prehospital providers to determine who really needs to go to the closest appropriate center, and what that really is.
Reference: Scoop and run to the trauma center or stay and play at the local hospital: hospital transfer’s effect on mortality. J Trauma 69(3):595-601, 2010.