January 2008

EMS Equipment

by Will Chapleau

Hemostatic Dressings Help Control Bleeding

Dressings engineered to assist bleeding control may seem to be a redundant statement, and you may be thinking that all dressings are designed to assist in bleeding control.

Of course the purpose of any dressing is to cover wounds and the bandage assists in applying enough pressure to control the bleeding, but the latest generation of dressings are engineered to assist in bleeding control through different mechanisms – hemostatic agents to assist clotting.

We all are trained to apply direct pressure to wounds, and historically the majority of the injuries we see are appropriately and effectively treated in this manner. Some would argue there are specific injuries and situations in which direct pressure is either ineffective or not immediately possible.

Consider A Battlefield

Consider for a moment treating the injured on an active battlefield or in a civilian tactical situation in which not only the casualties or patients are under fire, but any rescuers close enough to the injured are in jeopardy as well. Applying direct pressure might not be practical until the injured are moved to a secure location.

Some would also argue that large vessel injuries, like lacerated brachial or femoral arteries, could be difficult to control. Consider the critically injured patients you’ve seen in your career. The patient has multiple injuries, only one of which is the big bleeder. You’ve applied direct pressure, applied the pressure dressing, and then you have to manage another problem. When you check on the dressing later on, the dressing has bled through and slipped off the wound.

In that situation a hemostatic dressing, designed to assist in clotting would certainly help.

Three Topical Agents

The 6th edition of the Prehospital Trauma Life Support text (PHTLS), which was released in 2006, describes three topical hemostatic agents approved for use by the federal Food and Drug Administration (FDA). Of these, one works by becoming sticky when in contact with blood, and the other two absorb fluid from the bleeding site, allowing the concentration of clotting factors to increase enhancing the formation of clots. All three of these are actively marketed to emergency medical services in the U.S.

QuickClot is distributed by Z-Medica. The active ingredient is Zeolite, a patented formulation taken from volcanic rock. It works by absorbing the fluid out of the blood, concentrating clotting factors. Used on the battlefields of Afghanistan and Iraq, QuickClot is provided in mesh bags that are applied directly to the wound after removing excess blood with gauze. Applying direct pressure with the mesh bag onto the wound, the Zeolite activates, and bleeding should be controlled.

One concern that has been expressed about QuikClot is that as it works it creates an exothermic reaction and has caused additional injury in some patients in the form of burns. Temperatures of up to 150 degrees Fahrenheit have been documented. QuickClot feels it has addressed this with a new formulation. With QuickClot ACS+, the increases in surface temperatures were reduced by 45 percent, down to temperatures around 105 degrees Fahrenheit, according to the maker.

Hemorrhage Control Technologies of Portland, Ore., offers HemCon. This is a dressing impregnated with Chitosan which is a protein derived from shellfish. While much of the study done using QuickClot was done with the U.S. Navy, HemCon was the choice for study by the U.S. Army. This impregnated dressing becomes sticky when in contact with blood, which promotes sealing of the wound. If you’re concerned about the fact that it comes from shellfish, there have been no reported cases of reaction from patients with histories of sensitivity to shellfish.

The third product is called TraumaDex, and it is distributed in the U.S. by Emergency Medical Products. TraumaDex uses microporous polymer particles (granules) that have been synthesized from plant products (starch). Company literature describes clotting within seconds of application of the product. It works in a manner similar to other hemostatic treatments in that it dehydrates the blood, taking the fluid out of the blood and concentrating the clotting agents.

In looking at the potential for these dressings for prehospital trauma care, the authors of PHTLS looked at the available data from scientific studies and made the following statements.

First, they said the studies that evaluated the effectiveness of HemCon and QuickClot frequently used lacerated animal livers and large vessels in situations that don’t closely approximate the typical trauma patient for product evaluations.

While other anecdotal (non-scientific) information from military operations is favorable, there are no civilian real-time trauma applications to evaluate. The authors went on to say it would be inappropriate to delay transport or traditional direct pressure methods in order to use these applications. They described QuickClot as probably the most effective hemostatic agent, but they were concerned about the exothermic reactions. At the time of publication, the alternative formulation purported to reduce this effect was not available for evaluation.

Given the science available, PHTLS recommended that direct pressure remain the primary treatment, but that HemCon and QuickClot may be appropriate for prolonged transport situations. While not stated in the PHTLS text, battlefield or civilian tactical situations might also be a place where these types of dressings may be helpful when direct pressure is difficult or impossible to maintain.

Editor’s Note: Will Chapleau, who has 30 years of EMS experience, is the Advanced Trauma Life Support (ATLS) program manager for the American College of Surgeons. He is the former chief of the Chicago Heights (Ill.) Fire Department, has served since 1996 as the chairperson for the Prehospital Trauma Life Support (PHTLS) program of the National Association of Emergency Medical Technicians and has been a member of its international faculty since 1984. He is a board member of the National Association of EMS Educators.