M. Scerbo1, J. B. Holcomb1, K. Gates1, B. A. Cotton1 1University Of Texas Health Science Center At Houston,Houston, TX, USA
Introduction: Field use of tourniquets (TQ) in military medicine is regarded as an effective adjunct for preventing hemorrhage-related deaths from extremity trauma. Application in the civilian setting, however, has been accepted sporadically due to the paucity of evidence supporting efficacy. Subsequently, there have been no randomized, controlled trials assessing the efficacy of pre-hospital (PH) TQ application. Our urban EMS system has been training pre-hospital personnel to use TQ since 2009. The purpose of this study was to assess whether PH TQ use in the civilian setting decreases death from hemorrhagic extremity trauma.
Methods: Following IRB approval, patients arriving to a level-1 trauma center between 01/2009 and 05/2013 with an extremity injury and a PH TQ applied were reviewed. Control patients were obtained from the trauma registry prior to PH TQ implementation (01/2003 to 12/2008) and were eligible for matching if they had (1) Extremity Abbreviated Injury Severity (AIS) ≥ 2 and (2) OR exploration /control of extremity vascular injury or (3) death with extremity injury likely to have a vascular injury. Patients were propensity-score matched by age, gender, body mass index, mechanism of injury, method of transport and race. Matching occurred via a 1:1 ratio, with caliper and no replacement. Continuous data are presented as medians with 25th and 75th interquartile ranges. Categorical data are reported as proportions. Univariate and multivariate analyses were performed.
Results:
110 patients had PH TQ placement. Of 6961 control patients with AIS Extremity ≥ 2, 380 fulfilled all criteria for matching. Propensity matching yielded a sample size of 61 patients per group. Cases and controls displayed predominate isolated extremity injury (ISS 9 (4, 16) vs. 9 (8,18); AIS Extremity 3 (2, 3) vs 3 (2, 3)). The rate of vascular repair was similar between the two groups (89% vs 80%, p=0.212). Patients without a PH TQ had lower systolic blood pressure (109 mmHg (83, 135) vs 124 mmHg (93, 154) P <0.05) and hemoglobin 11 g/dL (9, 13) vs 13 g/dL (11,14) p<0.001) upon arrival. Failure to apply a PH TQ was associated with an increase mortality (21% vs 5%, OR 5.2 95% CI 1.31-29.9, p < 0.01). Similarly, there was a lower percentage of expected survivors in the patients that did not receive a PH TQ (31% vs 67%, p=0.001). Patients that did not receive a PH TQ had a higher resuscitation intensity (4.1 (1, 11.25) vs. 7.5 (3.4, 14.2) p<0.05).
Conclusion: Pre-hospital TQ application is associated with improved mortality from severe extremity injury in the civilian setting.