Increased Use of Prehospital Tourniquet and Patient Survival: Los Angeles Countywide Study

Recent trends in prehospital tourniquet use remain underreported. In addition, the impact of prehospital tourniquet use on patient survival has not been evaluated in a population-level study. We hypothesized that prehospital tourniquets were used more frequently in Los Angeles County and their use was associated with improved patient survival.

This is a retrospective cohort study using a database maintained by the Los Angeles County Emergency Medical Services Agency. We included patients who sustained extremity vascular injuries between October 2015 and July 2019. Patients were divided into the following study groups: prehospital tourniquet and no-tourniquet group. Our primary end point was in-hospital mortality. The secondary outcomes included 4- and 24-hour transfusion requirements and delayed amputation.

A total of 944 patients met our inclusion criteria. Of those, 97 patients (10.3%) had prehospital tourniquets placed. The rate of tourniquet use increased linearly throughout our study period (goodness of fit, p = 0.014). In multivariable analysis, prehospital tourniquet use was significantly associated with improved mortality (adjusted odds ratio 0.32; 95% CI, 0.16 to 0.85; p = 0.032). Similarly, transfusion requirements were significantly lower within 4 hours (regression coefficient -547.76; 95% CI, -762.73 to -283.49; p < 0.001) and 24 hours (regression coefficient -1,389.82; 95% CI, -1,824.88 to -920.97; p < 0.001). There was no significant difference in delayed amputation rates (adjusted odds ratio 1.07; 95% CI, 0.21 to 10.88; p < 0.097).

Prehospital tourniquet use has been on the rise in Los Angeles County. Our results suggest that the use of prehospital tourniquets for extremity vascular injuries is associated with improved patient survival and decreased blood transfusion requirements, without an increase in delayed amputations.