Trauma Surg Acute Care Open. 2019 Jan 24;4(1):e000267. doi: 10.1136/tsaco-2018-000267. eCollection 2019.

# Effect of prehospital tourniquets on resuscitation in extremity arterial trauma.

McNickle A, Fraser D, Chestovich P, Kuhls D, Fildes J

Background: Timely tourniquet placement may limit ongoing hemorrhage and reduce the need for blood products. This study evaluates if prehospital tourniquet application altered the initial transfusion needs in arterial injuries when compared with a non-tourniquet control group.

Methods: Extremity arterial injuries were queried from our level I trauma center registry from 2013 to 2017. The characteristics of the cohort with prehospital tourniquet placement (TQ+) were described in terms of tourniquet use, duration, and frequency over time. These cases were matched 1:1 by the artery injured, demographics, Injury Severity Score, and mechanism of injury to patients arriving without a tourniquet (TQ-). The primary outcome was transfusion within the first 24 hours, with secondary outcomes of morbidity (rhabdomyolysis, renal failure, compartment syndrome), amputation (initial vs. delayed), and length of stay. Statistical tests included t-test and χ2 for continuous and categorical variables, respectively, with p<0.05 considered as significant.

Results: Extremity arterial injuries occurred in 192 patients, with 69 (36%) having prehospital tourniquet placement for an average of 78 minutes. Tourniquet use increased over time from 9% (2013) to 62% (2017). TQ+ patients were predominantly male (81%), with a mean age of 35.0 years. Forty-six (67%) received blood transfusion within the first 24 hours. In the matched comparison (n=69 pairs), TQ+ patients had higher initial heart rate (110 vs. 100, p=0.02), frequency of transfusion (67% vs. 48%, p<0.01), and initial amputations (23% vs. 6%, p<0.01). TQ+ patients had increased frequency of initial amputation regardless of upper (n=43 pairs) versus lower (n=26 pairs) extremity involvement; however, only upper extremity TQ+ patients had increased transfusion frequency and volume. No difference was observed in morbidity, length of stay, and mortality with tourniquet use.

Discussion: Tourniquet use has increased over time in patients with extremity arterial injuries. Patients having prehospital tourniquets required a higher frequency of transfusion and initial amputation, without an increase in complications.

Level of evidence: Therapeutic study, level IV.