Outcomes excellent for tourniquets and hemostatic gauze in rural civilian populations
For much of the 20th century, the common view of tourniquets was that they lost more limbs than they saved. Associated with serious complications, including permanent muscle, nerve and soft tissue damage, tourniquets were considered a treatment of last resort and their use was discouraged in both military and prehospital settings.
Attitudes about tourniquets changed during the wars in Iraq and Afghanistan when commercial devices such as the Combat Application Tourniquet (C-A-T) were found to significantly reduce mortality from extremity hemorrhage with minimal morbidity. Retrospective studies of injured soldiers demonstrated that tourniquets were safe and effective when applied early and correctly. Now, all military personnel carry tourniquets and hemostatic agents such as QuikClot gauze and are trained to use them.
Outside the military, acceptance has been slower, however, and little data exist about the civilian use of these interventions. "Tourniquets and hemostatic agents clearly save lives in a military population of young men with wartime injuries. But whether they would perform as well in a markedly different civilian population with a wide range of ages, medical comorbidities and injuries wasn't known," explains Jennifer M. Leonard, M.D., Ph.D., chief resident of general surgery at Mayo Clinic's campus in Minnesota.
To fill this knowledge gap, Mayo researchers conducted a retrospective review of 95 patients treated with tourniquets, hemostatic gauze or both in the prehospital setting from 2009 to 2014. The patients were drawn from Gold Cross Ambulance and Mayo One Transport databases. Most ranged in age from 16 to 65, and 70 percent were male.
In addition to demographics, the researchers collected detailed information about tourniquet and hemostatic gauze use, complications and effectiveness. For purposes of the study, effectiveness was defined as cessation of clinically significant hemorrhage and was assessed by the prehospital providers. All cause morbidity was measured and defined as the sum of traumatic injuries, procedures and complications.
Overall, 98 percent of tourniquets successfully controlled arterial bleeding from blunt force trauma and penetrating wounds. Eleven percent of the devices were used for hemorrhage from non-traumatic injuries, including dialysis fistula rupture, bleeding related to arteriovenous malformations and advanced malignancies.
"What we saw was that commercial tourniquets were not only safe and effective for traumatic injuries but also for uncontrolled bleeding as a complication of dialysis," Dr. Leonard says. "We're looking into the use of tourniquets for fistula hemorrhage more closely because, in this small sample, all fistulae were functional after tourniquet application.
"Our data show that providers may not have to worry that tourniquet application will result in loss of vascular access. Based on this, we think hemodialysis units may want to stock tourniquets and hemostatic gauze, and high-risk dialysis patients may benefit from being trained to use and carry them."
Mayo's prehospital protocol requires that tourniquets remain in place until the patient reaches the emergency department or operating room. The median intervention-in-use time for tourniquets was 21 minutes, with a maximum of just over two hours. Within these time frames, morbidity was low and likely related to the traumatic injuries themselves — all major morbidities, including amputation, fasciotomy and acute kidney injury, were seen in patients with the most severe injuries.
"We saw no significant association between the risk of amputation following tourniquet application and older age, medical comorbidities or obesity," Dr. Leonard says. "But high abbreviated injury scale scores were significantly associated with amputation risk, suggesting that injury, not tourniquet use, was the cause."
Hemostatic agents control hemorrhage by concentrating clotting factors in the blood and augmenting the coagulation process. They are recommended when direct pressure, standard compression bandages or tourniquets have failed or are impractical.
In the Mayo Clinic study, QuikClot gauze stopped bleeding in 89 percent of patients and was effective for head and neck injuries as well as for junctional and extremity wounds that were inappropriate for tourniquets. QuikClot patients experienced only minor morbidity, mainly superficial wound infections that would be expected for contaminated traumatic injuries.
The initial Mayo Clinic study, which was published in the Journal of Special Operations Medicine in 2015, was the first to document the civilian experience with tourniquets and hemostatic bandages. It was followed by another study looking at clinical outcomes in the same population. Dr. Leonard was first author on the second study, which has been submitted for publication. Although relatively small, both studies clearly show that these interventions are safe and effective in the civilian prehospital setting.
Convincing the public and providers of their efficacy is the next step, Dr. Leonard says. "We need to convey to prehospital providers that tourniquets don't increase morbidity. It's true that if a C-A-T isn't fastened tightly enough to result in arterial occlusion, it can cause increased venous bleeding, and that can be a significant problem. You can't partially apply a tourniquet; it should be applied 2 to 3 inches above the wound and tightened to occlude arterial blood flow — if you can feel the distal pulse, it needs to be tighter."
That's why education is key, she says, and why Mayo providers undergo computer-based and hands-on training in the use of tourniquets and hemostatic gauze. The training leads to proficiency that has been shown to persist for at least two years, despite infrequent use.
"After looking at all the data, I wouldn't hesitate to put a tourniquet on a massively hemorrhaging wound," Dr. Leonard says. "There is nothing to lose unless it isn't tight enough, and everything to gain."
For more information
Bulger EM, et al. An evidence-based prehospital guideline for external hemorrhage control: American College of Surgeons Committee on Trauma. Prehospital Emergency Care. 2014;2:163.
Zietlow JM, et al. Prehospital use of hemostatic bandages and tourniquets: Translation from military experience to implementation in civilian trauma care. Journal of Special Operations Medicine. 2015;15:48.