 The Combat Application Tourniquet |
During times of conflict in human history, there have been some medical needs that have priority over the rest. One of these needs is the ability to control bleeding. Whether it is a police officer injured in the line of duty, or an injury sustained in a fire fight in Iraq, serious bleeding must be controlled quickly and effectively.
In recent years there have been great strides in this realm, and a number of new products have found their way into the market. There are newer and more effective tourniquets to staunch the flow of blood, powders and granules to be poured into wounds, and dressings to be stuffed into and on top of them. There are many choices available to control severe bleeding and it is important to understand the differences between them.
First, it needs to be clearly said that the tried-and-true methods of direct pressure, traditional bandaging, and elevation are very effective for controlling external bleeding from most wounds. I have seen several occasions where people have been quick to use the latest and sexiest devices before employing these basics. This is often to the patient’s detriment.
Tourniquets
The tourniquet, surrounded by myth and controversy, has been used since Roman times. It gained a poor reputation during the American Civil War period largely due to misuse and misconception. Today we know that a good tourniquet is rightly viewed as an effective bleeding control device. Early tourniquets, especially those like the improvised cravats-and-stick and the World War II-era strap and buckle, were often ineffective as they did not generate sufficient tension to occlude the arteries running deep in the muscle tissue. Additionally, they were left on for long periods of time — sometimes for days during the Civil War — before more comprehensive medical care was delivered. This lead to the many complications still feared with tourniquet use today.
Research in the past several decades show that tourniquets hold far less risk than previously thought. They do not automatically lead to loss of the extremity as once believed if used as a short-term modality. Evidence of this can be found in the modern operating room, where tourniquets are often employed for periods of up to six hours during various surgical procedures.
Their presence on today’s battlefield is almost universal. One example is the Combat Application Tourniquet currently deployed as the U.S. Army’s preferred issue. The CAT does an outstanding job of controlling extremity bleeding when properly applied, and its strengths lie in its efficacy, its ability to be applied quickly, and ease of use for one-handed application for self-care. Tourniquets have become so popular in some venues that at least one company is manufacturing clothing with them built-in to the legs and sleeves.
Hemostatic agents
Hemostatic agents are the granules, powders and impregnated dressings created to increase blood clotting and stop serious hemorrhaging more quickly. They have been used in various forms throughout most of the 20th century, from hemostatic glues and patches used in surgery to the more common types used in today’s emergency setting.
A great deal of research has been done on their use in trauma, especially in the context of the war in Iraq and Afghanistan. A preponderance of this research shows that they all are basically effective in stopping bleeding — with some idiosyncrasies.
QuikClot is a popular brand that has undergone a number of changes since its arrival on the market. It was initially a finely-ground powder that was poured into wounds. The mixture absorbed the water out of the blood, concentrating the remaining blood components and increasing clotting. The early formulations caused a very strong heat reaction in the wound, which caused even more pain and damage to surrounding tissue. The fine, powdery quality has also lead to reports of problems caused by it being blown onto wet hands and even into the eyes of the medical caregiver.
 QuikClot |
QuikClot has changed its form and its chemical formulations and the original powder is no longer produced by the manufacturer. QuikClot “First Response,” consisting of a newer granule substance in a mesh bag that is packed directly into the wound, is effective and has become popular in both military and civilian emergency medicine. There is also a chemically-impregnated roll of QuikClot “Combat Gauze,” which has recently been chosen to become one of the U.S. Army’s first line weapons against severe bleeding.
Another popular hemostatic agent is WoundStat, a granulated substance that is poured and packed into wounds creating a sticky seal over the bleeding site. It has also been chosen by the U.S. Army as standard issue, and like QuikClot has been shown to be effective in wounds where a tourniquet cannot be applied. WoundStat appears to perform better than QuikClot and other granulated or powdered hemostatic substances due to its ability to stick in wounds that even have spurting or high pressure bleeding.
However, last month it was reported that the U.S. Army is stopping the issue of WoundStat to troops due to the possible creation of blood clots inside the vessels, causing harm to the patient. The manufacturer of WoundStat has stated that expert opinions differ on the U.S. Army’s testing methods, and continued testing in conjunction with the Army is in progress.
HemCon dressings were widely issued in the military until very recently. It is a hard, wafer-like dressing impregnated with a clotting agent called “chitosan,” derived from shrimp shells. Once moistened with blood, it forms a sticky, glue-like bandage over the bleeding site. HemCon’s longer-term efficacy (two hours or more) has recently been called into question by some studies.1 The price tag is also high at $100 per individual gauze.
There are other agents also used to control bleeding. Two that appear to be effective, but for various reasons have seen lesser action in the field, are TraumaDex and Celox. Both of these are chitosan-based agents that are poured into the wound. Another is an injectable medication called NovoSeven, used by some civilian and military trauma hospitals.
A Word of Advice
Competent use of these new blood-stopping devices has undoubtedly saved the lives of many trauma victims. Even better news is that agents are being developed and improved constantly. But a word of advice; if you decide to arm either your medic bag or your entire agency with a hemostatic agent, proper training is essential. As with other tools you carry, indiscriminate or improper use of blood-clotting devices can not only hinder your life-saving efforts, but may also cause additional harm.
References
1Kheirabadi BS, et al. Hemostatic efficacy of two advanced dressings in an aortic hemorrhage model in Swine. J Trauma. 2005 Jul; 59(1):25-34.
