Recent studies have shown that civilian tourniquet use dramatically reduces the risk of death for injured patients. But how do prehospital tourniquets affect other patient outcomes?

According to a new study from Tulane University, civilian tourniquet use for penetrating extremity bleeding is associated with a lower incidence of shock and decreased blood product utilization. The study also found that tourniquets applied by first responders do not increase the risk of major limb complications.

The Tulane study was published in the January 2019 issue of The Journal of Trauma and Acute Care Surgery. Using retrospective data on patients with penetrating major extremity trauma, the investigators compared 127 patients who received a prehospital tourniquet to a matched cohort of 77 patients who did not. The control group was matched for patient demographics and injury severity.

More than 95% of tourniquets were applied by a paramedic, EMT, police officer or firefighter, although some patients first received an improvised tourniquet from a bystander. Here are the takeaways:

• Lower incidence of shock: Patients who received a tourniquet had higher average systolic blood pressure on arrival in the emergency department (120 ± 2 versus 112 ± 2)
• Decreased use of blood products: Tourniquet patients required less total packed red blood cells (2.0 ± 0.1 versus 9.3 ± 0.6) and less fresh frozen plasma (1.4 ± 0.08 versus 6.2 ± 0.4)
• Lower incidence of limb complications: Patients who received a tourniquet were much less likely to require fasciotomy (12.6% versus 31.4%) or amputation (0.8% versus 9.1%)

In addition, tourniquet use was not associated with nerve palsy or secondary infection.

“Our study demonstrates that prehospital tourniquets can be safely used to control bleeding in compressible penetrating extremity hemorrhage,” the authors concluded. By controlling bleeding until definitive interventions can be performed, the use of prehospital tourniquets could improve long-term outcomes for trauma patients.

Tourniquet use increased 20 times during the study

The Tulane researchers noted that the use of tourniquets by New Orleans first responders has increased dramatically in recent years: “An analysis of trauma patients presenting to our Level I trauma center from 2010 to 2018 showed a steady increase in the frequency [of]  tourniquet application, from 2.2/1000 trauma activations in 2010 to 44.9/1000 trauma activations in 2018.”

Prehospital tourniquet use is significantly higher in New Orleans than in other regions, due in large part to the efforts of the late Norman McSwain. As tourniquet use increases, the risk of overuse may become a danger. In fact, during the period of this study the average AIS score of patients who received a prehospital tourniquet decreased from 3 to 2.1.

“This observation is certainly concerning that tourniquets are being used more liberally and eventually, the risks of frequent tourniquet placement might outweigh potential benefits,” the authors noted. “At present, we are continuing to collect outcomes associated with prehospital tourniquet use in our patients to ensure safety and quality care.”