N'oublions pas le packing de plaie

A manikin model for study of wound-packing interventions to control out-of-hospital hemorrhage

Kragh JF et Al. Am J Emerg Med. 2014 Sep;32(9):1130-1

 

To the Editor,

With hemorrhage being the primary cause of mortality on the battlefield [1-3], wound-packing practice by US military medics in the wars since September 11, 2001, has changed from a conservative to an assertive approach. The foremost emphasis changed from preventing contamination to controlling hemorrhage. As no specific hemostatic dressings were available at the start of the wars, after such dressings were fielded, medics changed their approach by packing wounds with more gauze earlier in casualty care and deeper into subfascial cavitary wounds as a way to control hemorrhage. Although experienced medics and trainers favor an assertive approach, there is limited empirical evidence of improvements. In addition, with the development of various dressings with hemostatic properties [4-6], no systematic approach to trial wound-packing techniques easily has been developed. When a war ends and military medical care shifts toward peacetime duties and garrison work, skill sets in trauma care degrade as skill performance is less often. Furthermore, peacetime training reverts back toward everyday work such as sick call and away from future combat casualty care. The reversion tendency allows less training of new medics in combat casualty care than those who were trained during busy years of sustained combat; like nothing in peacetime, the present danger of combat during wartime focuses attention on hemorrhage control. A challenge for medics to be as well trained in peacetime in combat casualty care as during wartime is a recurring theme of military medicine.

Of the medical advances in prehospital combat casualty care during the current wars, we feel that the most important are regular tourniquets, junctional tourniquets, and wound packing because of their potential capacity to save numerous casualties from the most common cause of death on the battlefield—wound exsanguination. To not backslide on these 3 skills, we continue scholarly work to refine them. We call these skills the “Big 3,” and we have published mostly on tourniquets. To stimulate development of best practices in wound packing, we now focus the present report on an introductory test method to increase awareness of knowledge gaps within the science of wound packing. 

The purpose of the present study is to introduce a laboratory model of hemorrhage with data comparing gauze wound packing and medical device use to better understand out-of-hospital hemorrhage control. In an approved protocol, we used a manikin model designed for the capacity to train medics in techniques of gauze wound packing for hemorrhage control in trauma care. The manikin trainer (Combat Ready Clamp [CRoC] Trainer Manikin; Operative Experience, Inc, North East, MD) had a gunshot wound of the right groin that bled water from the common femoral artery; the wound track went through the thigh posterior to anterior. We measured blood volume lost from bleeding, the application time, and hemorrhage control (yes-no). We had only 1 user who had never packed a wound prehospital and had never been trained in this task. We made 4 tests. The first test was that we used a type of gauze (QuikClot Combat Gauze; Z-Medica, Wallingford, CT) alone in accordance with its instructions for use (IFU) except we used no overwrap for pressure; the overwrap is the fourth and final step of the gauze IFU. The second test was like the first, but we used the full IFU that included use of an overwrap (AirWrap, RevMedx, Wilsonville, OR). The third test was only the A manikin model for study of wound-packing interventions to control out-of-hospital hemorrhage

 use of the overwrap and no gauze; this test included no inflation of the pneumatic bladder within the overwrap. The fourth test included the gauze, the overwrap, and the inflation of the overwrap. Each test had 4 replicates.

The results showed an apparent differential performance of the methods of hemorrhage control, but the test order indicated possible learning that may be a confounder. The fourth test performed better than the first 3 with respect to reduced blood loss (Fig. 1), which may mean that the fourth method is best or that the user learned with experience. Perhaps both are true. Application time also improved (Fig. 2), and the evaluation was sensitive enough to detect longer application times with additional steps in the wound-wrapping process.



There was no surprise that the gauze performed better as indicated by reduced blood loss (Fig. 1) when it was used fully in accordance with its IFU in that the second test performed better than the first. In addition, there was no surprise that the overwrap performed better when it was used fully in accordance with its intent in that the fourth test performed better than the third since the overwrap was designed to wrap over gauze.

The strength of this report is that it introduces a method of analyzing wound-packing techniques that generated hypotheses for testing. Hypothesis-driven experiments will follow this hypothesis generating report to check differential performance of techniques such as preliminarily studied here. The method permits learning curve analysis to see how fast users can be in hemorrhage control; we have previously found that tourniquet use, for example, appears to take more than 30 tests before users flatten their learning curve [7].

Determining optimal care techniques and training regimens may help to improve clinical performance. The limitation of the present report is its introductory design; the preliminary finding is only able to generate hypotheses. Future directions include analyses of techniques and learning curves.

 

John F. Kragh Jr., MD

US Army Institute of Surgical Research

Joint Base San Antonio

Fort Sam Houston, TX

Uniformed Services University of the Health Sciences

F. Edward Hébert School of Medicine Bethesda, MD

Corresponding author at: US Army Institute of Surgical Research

Damage Control Resuscitation, 3698 Chambers Pass

Ste B, Joint Base San Antonio

Fort Sam Houston, TX

E-mail address: [e-mail]

 

John Steinbaugh

RevMedx, Inc, Wilsonville, OR

Donald L. Parsons, PA-C

Combat Medic Training

US Army Medical Department Center and School

Joint Base San Antonio, Fort Sam Houston, TX

 

Robert L. Mabry, MD

Emergency Medical Services Fellowship

San Antonio Military Medical Center

Joint Base San Antonio

Fort Sam Houston, TX

Bijan S. Kheirabadi, PhD

Michael A. Dubick, PhD

Damage Control Resuscitation

US Army Institute of Surgical Research

Joint Base San Antonio

 

Fort Sam Houston, TX