Hawk AJ
J Trauma Acute Care Surg. 2018 Jul;85(1S Suppl 2):S13-S17.
BACKGROUND: Just over 200 years ago, surgeons were puzzled that the use of the tourniquet to control hemorrhage as common sense during surgery was a relatively recent development. Within the last 20 years, much progress has been made to controlling hemorrhage in the prehospital context. Then, as now, it was surprising that progress on something that appeared obvious had occurred only recently, begging the question how controlling blood loss was common sense in a surgical context, but not for emergency treatment.
METHODS: Paper is a historical survey of the evolution of the medical understanding of hemorrhage along with technological response.
RESULTS: The danger of blood loss had historically been consistently underestimated as physicians looked at other explanations for symptoms of how the human body responded to trauma. As the danger from hemorrhage became apparent, even obvious, responsibility for hemorrhage control was delegated down from the surgeon to the paramedic and eventually to individual service members and civilian bystanders with training to "Stop the Bleed."
DISCUSSION: Hippocratic medicine assumed that blood diffused centrifugally into periphery through arteries. William Harvey's observation in 1615 that blood ran through a closed circulatory system gradually transformed conventional wisdom about blood loss, leading to the development of the tourniquet about a century later by Jean-Louis Petit, which made amputation of limbs survivable. However, physicians were cautious about their application during the First World War over concerns over effects on patient recovery. Hemorrhage had generally been seen as symptom to be managed until the patient would be seen by a surgeon who would stop the bleeding. More thorough collection and analysis of data related to case histories of soldiers wounded during the Vietnam Conflict transformed how surgeons understood the importance to hemorrhage leading to development of the doctrine of Tactical Combat Casualty Care in the late 1990's.
STUDY TYPE: economic/decision
LEVEL OF EVIDENCE: Background Information.
Holcomb JB
Crit Care Med. 2018 Mar;46(3):447-453
OBJECTIVES: Experience in the ongoing wars in Iraq and Afghanistan confirm that faster transport combined with effective prehospital interventions improves the outcomes of patients suffering hemorrhagic shock. Outcomes of patients with hemorrhagic shock and extremity bleeding have improved with widespread use of tourniquets and early balanced transfusion therapy. Conversely, civilian patients suffering truncal bleeding and shock have the same mortality (46%) over the last 20 years. To understand how to decrease this substantial mortality, one must first critically evaluate all phases of care from point of injury to definitive hemorrhage control in the operating room.
DATA SOURCES: Limited literature review.
DATA SYNTHESIS: The peak time to death after severe truncal injury is within 30 minutes of injury. However, when adding prehospital transport time, time spent in the emergency department, followed by the time in the operating room, it currently takes 2.1 hours to achieve definitive truncal hemorrhage control. This disparity in uncontrolled truncal bleeding and time to hemorrhage control needs to be reconciled. Prehospital and emergency department whole blood transfusion and temporary truncal hemorrhage control are now possible.
CONCLUSIONS: The importance of rapid transport, early truncal hemorrhage control and whole blood transfusion is now widely recognized. Prehospital temporary truncal hemorrhage control and whole blood transfusion should offer the best possibility of improving patient outcomes after severe truncal injury.
Tjardes T, Luecking M
Mil Med. 2018 May 1;183(5-6):e207-e215
Introduction: To achieve the aim of zero preventable deaths on the battlefield a deeper understanding of uncontrolled hemorrhage from junctional or proximal extremity sources is mandatory. While tourniquet application to the extremities has drastically reduced morbidity and mortality, there is still room for improvement regarding the timing of tourniquet placement as the available evidence clearly points out a tight correlation between timing of tourniquet application and outcome. To save as many lives as possible the "point of no return" regarding the circulatory breakdown due to hemorrhage, colloquially addressed as platinum 5 min, needs to be determined. As clinical analysis or controlled studies are difficult, if not impossible, and animal experiments cannot be translated to bleeding in humans, we present a mathematical modeling approach. The key assumption of the model is that hemodynamics in the early phase of massive hemorrhage are determined by the cardiac function, the passive physical properties of the vascular system, that is, compliances etc., as humoral compensatory mechanisms kick in at a later point in time, and the baroceptor reflex, which constitutes the immediate response to volume loss.
Materials and Methods: A lumped mathematical model based on differential equations describing three distinct arterial and two venous compartments, the heart and the baroceptor mechanism is developed. With this model, different patterns of blood loss (%) and duration of bleeding (s) are simulated: 10%/30 and 60 s, 20%/30 and 60 s, 30%/30, 60 and 120 s, and 35%/30, 120 and 180 s. These bleeding patterns are chosen such that they resemble clinically scenarios following junctional and proximal extremity injuries.
Results: Three hemodynamic patterns can be distinguished. The system stabilizes on a lower blood pressure level (10%/30 and 60 s, 20%/30 and 60 s), the system formally stabilizes on a very low level, which is physiologically not reasonable (30%/30, 60 and 120 s), the system irreversibly breaks down with no signs of restabilization (35%/30, 120 and 180 s).
Conclusion: Thus the immediacy of intervention in terms of application of a tourniquet is clearly emphasized by the simulation, that is, the window of opportunity for a life-saving intervention, especially in a combat setting, is significantly smaller than the symbolic "platinum five minutes" might suggest. With respect to the 3-min window of opportunity identified in the simulations the effective application of these devices in a TCCC setting appears questionable. Given these observations, further research and development into solutions that allow the timely identification of a junctional bleeding problem and application of compression is necessary.
Bogdan Y, Helfet DL
Orthop Clin North Am. 2018 Apr;49(2):157-165.
Although tourniquets are commonly used in patients with limb trauma patients, both in the acute and elective settings, no set protocols exist for their indications, contraindications, or proper use. This article addresses the current literature on optimal pressure, timing, cuff design, and complications of tourniquets in trauma patients. General issues are discussed, followed by those specific to upper and lower extremities. Lastly, serious complications, such as pulmonary embolism, are described.
Cunningham A, Auerbach M, Cicero M, Jafri M.
J Trauma Acute Care Surg. 2018 Feb 17. Epub ahead of print
BACKGROUND: Recent mass casualty events in the United States have highlighted the need for public preparedness to prevent death from uncontrolled hemorrhage. The Pediatric Trauma Society (PTS) reviewed the literature regarding pediatric tourniquet usage with the aim to provide recommendations about the utility of this adjunct for hemorrhage control in children.
METHODS: Search terms "pediatric" and "tourniquet" were used to query the US National Library of Medicine National Institutes of Health for pertinent literature. Exclusion criteria include: not involving children, not involving the use of an extremity tourniquet, primary outcomes not related to hemorrhage control, tourniquet use to prevent snake envenomation, single case reports, and only foreign language formats available. Bibliographies of remaining studies reviewed to identify additional pertinent research. Four physician members of the Pediatric Trauma Society Guidelines Committee reviewed identified studies.
RESULTS: One hundred and thirty four studies were identified. One hundred and twenty three studies were excluded. Seven additional studies were identified through bibliography review. Eighteen pertinent studies were reviewed. Seven articles evaluated physiologic response to tourniquet use in operating room settings. Six articles were generated from combat experience in conflicts in Afghanistan and Iraq. Four articles discussed technical details of tourniquet usage. One article evaluated the use of tourniquets during the Boston Marathon bombing in 2015.
CONCLUSIONS: Despite limited data of limited quality regarding their use, the PTS supports the usage of tourniquets in the pre-hospital setting and during the resuscitation of children suffering from exsanguinating hemorrhage from severe extremity trauma. Expedited, definitive care must be sought, and tourniquet pressure and time should be limited to the least amount possible. The Society supports the ACS 'Stop the Bleed' campaign and encourages further investigation of tourniquet use in children.
LEVEL OF EVIDENCE: 3a STUDY TYPE: Guidelines/Algorithm.
Glick CPTY, Furer MAJA, Glassberg COLE, Sharon R, Ankory MAJR
Mil Med. 2018 Mar 1;183(suppl_1):157-161
Introduction: Experience from recent conflicts underlines the dramatic impact of effective tourniquet use on combat casualty mortality. Although the Combat Application Tourniquet (CAT) is replacing the silicone band tourniquets (IST; "Israeli Silicone Tourniquet") in the Israeli Defense Forces, no direct comparison was made between them. The purpose of this study is to compare the performance of the two tourniquets on a mid-thigh model.
Methods: Participants were Israeli military recruits who previously had the military first aid course. Each participant applied both the CAT and the IST. Applications were assessed by the HapMed Leg Tourniquet Trainer, which measured the applied pressure and the time required to reach it.
Results: IST application resulted in higher rates of effective occlusion pressure compared with the CAT (91% vs. 73.1%, p < 0.01), and a higher mean occlusion pressure (41 mmHg, p < 0.01) was recorded using the IST. Among effective attempts, application time did not differ significantly between the tourniquets.
Conclusion: The IST was superior to the CAT in producing effective occlusion pressure while not prolonging application time. These results may indicate that the IST remains a valid option for controlling mid-thigh bleeding.
Kauvar DS, Dubick MA, Walters TJ, Kragh JF Jr.
J Trauma Acute Care Surg. 2018 May;84(5):819-825
BACKGROUND: Military enthusiasm for limb tourniquet use in combat casualty care has resulted in acceptance by the trauma community for use in the prehospital care of civilian limb injuries. To date, there has been no report synthesizing the published data on civilian tourniquet use. The objective of this systematic review was to compile and analyze the content and quality of published data on the civilian use of tourniquets in limb trauma.
METHODS: The MEDLINE database was searched for studies on civilian limb tourniquet use in adults published between 2001 and 2017. Search terms were tourniquet, trauma, and injury. Military reports and case series lacking systematic data collection were excluded. Counts and percentages were aggregated and weighted for analysis.
RESULTS: Reports were included from six regional trauma centers and one interregional collaboration (total of 572 cases). One national prehospital database report was included but analyzed separately (2,048 cases). All were retrospective cohort studies without prospective data collection. Three reports defined a primary outcome, two had a nontourniquet control group, and no two articles reported the same variables. Limb injury severity and characteristics were inconsistently and incompletely described across reports, as were tourniquet indications and effectiveness. Arterial injury was reported in two studies and was infrequent among cases of tourniquet use. Mortality was low, and limb-specific complications were infrequent but variably reported.
CONCLUSION: The rapid increase in the civilian use of tourniquets for limb hemorrhage control has occurred without a large amount or high quality of data. Adoption of a multicenter registry with standardized data collection specific to limb trauma and tourniquet use can serve to improve the trauma community's understanding of the safety and effectiveness of tourniquet use in civilian trauma settings.
LEVEL OF EVIDENCE: Systematic review, level IV.
Ross EM, Mapp JG, Redman TT, Brown DJ, Kharod CU, Wampler DA
J Emerg Med. 2018 Mar;54(3):307-314
BACKGROUND: The "Stop the Bleed" campaign in the United States advocates for nonmedical personnel to be trained in basic hemorrhage control and that "bleeding control kits" be available in high-risk areas. However, it is not clear which tourniquets are most effective in the hands of laypersons.
OBJECTIVES: The objective of this pilot study was to determine which tourniquet type was the most intuitive for a layperson to apply correctly.
METHODS: This project is a randomized study derived from a "Stop the Bleed" education initiative conducted between September 2016 and March 2017. Novice tourniquet users were randomized to apply one of three commercially available tourniquets (Combat Action Tourniquet [CAT; North American Rescue, LLC, Greer, SC], Ratcheting Medical Tourniquet [RMT; m2 Inc., Winooski, VT], or Stretch Wrap and Tuck Tourniquet [SWAT-T; TEMS Solutions, LLC, Salida, CO]) in a controlled setting. Individuals with formal medical certification, prior military service, or prior training with tourniquets were excluded. The primary outcome of this study was successful tourniquet placement.
RESULTS: Of 236 possible participants, 198 met the eligibility criteria. Demographics were similar across groups. The rates of successful tourniquet application for the CAT, RMT, and SWAT-T were 16.9%, 23.4%, and 10.6%, respectively (p = 0.149). The most common causes of application failure were: inadequate tightness (74.1%), improper placement technique (44.4%), and incorrect positioning (16.7%).
CONCLUSION: Our pilot study on the intuitive nature of applying commercially available tourniquets found unacceptably high rates of failure. Large-scale community education efforts and manufacturer improvements of tourniquet usability by the lay public must be made before the widespread dissemination of tourniquets will have a significant public health effect.
Teixeira PGR, Brown CVR, Emigh B, Long M, Foreman M, Eastridge B, Gale S, Truitt MS, Dissanaike S, Duane T, Holcomb J, Eastman A, Regner J; Texas Tourniquet Study Group.
Collaborators: Vu M, Todd SR, Rainey EE, Allen L, Agrawal V, Walker K, Gandhi R, Podbielski JM.
J Am Coll Surg. 2018 May;226(5):769-776
BACKGROUND: Tourniquet use has been proven to reduce mortality on the battlefield. Although empirically transitioned to the civilian environment, data substantiating survival benefit attributable to civilian tourniquet use is lacking. We hypothesized that civilian prehospital tourniquet use is associated with reduced mortality in patients with peripheral vascular injuries.
STUDY DESIGN: We conducted a multicenter retrospective review of all patients sustaining peripheral vascular injuries admitted to 11 Level I trauma centers (January 2011 through December 2016). The study population was divided into 2 groups based on prehospital tourniquet use. Baseline characteristics were compared and factors associated with mortality identified. Logistic regression, adjusting for demographic, physiologic and injury-related parameters, was used to evaluate the association between prehospital tourniquet use and mortality. Delayed amputation was the secondary end point.
RESULTS: During 6 years, 1,026 patients with peripheral vascular injuries were admitted. Prehospital tourniquets were used in 181 (17.6%) patients. Tourniquet time averaged 77.3 ± 63.3 minutes (interquartile range 39.0 to 92.3 minutes). Traumatic amputations occurred in 98 patients (35.7% had a tourniquet). Mortality was 5.2% in the non-tourniquet group compared with 3.9% in the tourniquet group (odds ratio 1.36; 95% CI 0.60 to 1.65; p = 0.452). After multivariable analysis, the use of tourniquets was found to be independently associated with survival (adjusted odds ratio 5.86; 95% CI 1.41 to 24.47; adjusted p = 0.015). Delayed amputation rates were not significantly different between the 2 groups (1.1% vs 1.1%; adjusted odds ratio 1.82; 95% CI 0.36 to 9.99; adjusted p = 0.473).
CONCLUSIONS: Although still underused, civilian prehospital tourniquet application was independently associated with a 6-fold mortality reduction in patients with peripheral vascular injuries. More aggressive prehospital application of extremity tourniquets in civilian trauma patients with extremity hemorrhage and traumatic amputation is warranted.