Justin Kleiner, Paul Tornetta III.

Response/Recommendation: Multiple factors have been studied to assess blood loss in acute trauma patients, and to predict the need for transfusion. Adequate risk stratification involves consideration of the patient’s vital signs, laboratory data, injuries, and medical history.

Strength of Recommendation: Low.

Rationale: Bleeding is a significant source of morbidity and mortality in trauma patients^1,2. Adequate resuscitation is an important aspect of management of trauma patients^3–5. In patients requiring surgery, under-resuscitation may delay operative treatment, and is associated with increased risk of complications. Many factors indicate an increased risk of substantial bleeding in trauma patients. A patient’s presenting vital signs, temperature, coagulopathic state, severity of injuries, mechanism of injury, as well as their medical comorbidities all contribute to the risk of bleeding in acute trauma. Prehospital care may also have an effect. A variety of scoring systems have been developed to guide clinicians in evaluating this risk^4,6–13.

Clinicians routinely use a trauma patient’s presenting blood pressure and tachycardia to evaluate sustained blood loss^2,8,14. Shock index, defined as heart rate/systolic blood pressure (HR/SBP), is a validated tool in stratifying blood loss and is simple to calculate in the acute trauma setting. El-Menyar et al., found that shock index greater than 0.8 was an independent predictor of transfusion and mortality⁸. Similarly, Vandromme et al., showed increased transfusion rates in patients with shock index greater than 0.9, and five-fold increase in transfusion rates with shock index greater than 1.1¹⁴. Cannon et al., found higher mortality in patients with a presenting shock index greater than 0.9¹⁰.

Other scoring systems for prior acute blood loss have been developed that supplement vital signs data with additional presenting laboratory values. The assessment of blood consumption (ABC) score considers SBP < 90, HR > 120, penetrating mechanism, and a positive Febuxostat versus Allopurinol streamlined trial (FAST) study^6,9. Patients with at least two of these are likely to require massive transfusion. However, Schroll et al., found ABC score to have lower sensitivity but greater specificity than shock index for predicting massive transfusion¹⁵. Further systems include the bleeding audit for trauma & triage (BATT) score, developed to predict hemorrhagic death in trauma, which uses SBP < 100, BP > 100, as well as respiratory rate, the Glasgow coma scale (GCS) score, age, penetrating mechanism, and high-velocity trauma¹². The head injury severity score (HISS) uses presenting labs of glucose, lactate, pH, potassium, and pO2 to predict mortality and intensive care unit (ICU) stay¹¹.

In addition to a patient’s presenting laboratory values and vital signs, overall injury burden and mechanism of injury contribute to bleeding risk. Rainer et al., showed that patients with displaced pelvic fractures had odds ratio of 7.6 for requiring massive transfusion¹⁶. Additionally, they showed that positive FAST score, injury severity score (ISS) greater than 25, and high energy motor vehicle collision (MVC) were associated with transfusion¹⁶. Further, the physiologic response to trauma varies by mechanism and has a significant impact on bleeding risk¹⁷. Blunt trauma without shock promotes a prothrombotic response due to diffuse tissue damage.¹⁸ However, penetrating trauma or trauma with shock may have produced a coagulopathic response associated with increased bleeding risk¹⁸. Given the variable effects of trauma on coagulation pathways, viscoelastic assays have been studied to monitor hemostasis in acute trauma^2,17. The use of thromboelastography (TEG) is used more widely in Europe than in North America, but more locations are evaluating this methodology¹⁹.

Patients requiring surgery are at increased risk of bleeding, and this varies with type of surgery needed. Patients who required hemostatic or endovascular surgery have been shown to require massive transfusion more frequently²⁰. In femur fracture patients receiving intramedullary nails, perioperative blood loss has been estimated at about 1,200cc using dilutional methods²¹. In acetabular fracture fixation, reported blood loss can be more than 2,000 cc depending on the pattern and approach, with approximately 40% requiring transfusion^22–24.

Medical history must also be considered when evaluating bleeding risk in trauma patients. Taking a personal and family history of bleeding is recommended in all preoperative patients²⁵. Medication history should routinely be reviewed, as patients on anticoagulation are also at higher risk of bleeding after trauma. Williams et al report anticoagulation and international normalized ratio (INR) > 1.5 were independent risk factors for mortality in trauma patients⁵.

Appropriate risk stratification for bleeding in trauma patients requires a multi-factorial approach. Multiple scoring systems exist to evaluate vital signs and laboratory data. In particular, hypotension and tachycardia on presentation consistently prove to be important factors in predicting significant blood loss. In addition to these tools, physicians should also consider overall injury burden, mechanism of injury, and patient medical history to appropriately stratify bleeding risk.

Factors that influence blood loss in orthopaedic trauma patients:

Injury-related factors

1. Presenting vitals/labs
   1. Shock index – (HR/SBP > 0.8) an independent predictor of transfusion and mortality⁸.
   1. HISS score uses presenting labs of glucose, lactate, pH, potassium, pO2 to predict mortality and ICU stay¹¹.
2. Overall injury burden/injury severity score
   1. Displaced pelvic fracture, positive FAST, increased ISS à increased risk of needing massive transfusion¹⁶.
   1. BATT score to predict hemorrhagic death: age, GCS, mechanism of injury, vital signs¹². The prediction of acute coagulopathy of trauma (PACT) score used similar variables⁷.
3. Mechanism of injury
   1. Blunt trauma with shock associated with increased risk of bleeding. The trauma brain injury (TBI) severity score is also associated with delayed clot formation¹⁸.
   1. Higher energy injury such as MVC associated with greater risk of massive transfusion²⁰.
   1. Can consider viscoelastic assays, however not widely used at this time
4. Planned surgery
   1. Major surgery associated with > 2% blood loss (joint replacement, major orthopaedic surgery, operation > 45 mins). Lower risk with arthroscopy, hand, or foot surgeries²⁶.
   1. Patients who required hemostatic or endovascular surgery more likely to need massive transfusion²⁰.

Patient-related factors

1. Bleeding related comorbidities
   1. Medical and family history of bleeding should be obtained in all preoperative patients²⁵.
2. Medications – anticoagulants, antiplatelet agents
   1. Anticoagulation and INR > 1.5 independent risk factors for bleeding and mortality⁵.
3. Additional medical comorbidities (capacity to compensate for blood loss/increased risk)
   1. BATT score shows correlation between increased age and hemorrhagic death¹².

References:

1.         Maegele, Marc[1] Maegele M. Acute traumatic coagulopathy: Incidence  risk stratification and therapeutic options. WJEM 2010;1:12–21. Acute traumatic coagulopathy: Incidence, risk stratification and therapeutic options. World J Emerg Med. 2010;1(1):12-21.

2.         Maegele M. The European Perspective on the Management of Acute Major Hemorrhage and Coagulopathy after Trauma: Summary of the 2019 Updated European Guideline. J Clin Med. 2021;10(2):362. doi:10.3390/jcm10020362

3.         Tran A, Matar M, Lampron J, Steyerberg E, Taljaard M, Vaillancourt C. Early identification of patients requiring massive transfusion, embolization or hemostatic surgery for traumatic hemorrhage: A systematic review and meta-analysis. J Trauma Acute Care Surg. 2018;84(3):505-516. doi:10.1097/TA.0000000000001760

4.         Cornero SG, Maegele M, Lefering R, et al. Predictive Factors for Massive Transfusion in Trauma: A Novel Clinical Score from an Italian Trauma Center and German Trauma Registry. J Clin Med. 2020;9(10):3235. doi:10.3390/jcm9103235

5.         Williams TM, Sadjadi J, Harken AH, Victorino GP. The Necessity to Assess Anticoagulation Status in Elderly Injured Patients. J Trauma – Inj Infect Crit Care. 2008;65(4):772-776. doi:10.1097/TA.0b013e3181877ff7

6.         Nunez TC, Voskresensky I V., Dossett LA, Shinall R, Dutton WD, Cotton BA. Early prediction of massive transfusion in trauma: Simple as ABC (Assessment of Blood Consumption)? J Trauma – Inj Infect Crit Care. 2009;66(2):346-352. doi:10.1097/TA.0b013e3181961c35

7.         Peltan ID, Rowhani-Rahbar A, Vande Vusse LK, et al. Development and validation of a prehospital prediction model for acute traumatic coagulopathy. Crit Care. 2016;20(1):1-10. doi:10.1186/s13054-016-1541-9

8.         El-Menyar A, Goyal P, Tilley E, Latifi R. The clinical utility of shock index to predict the need for blood transfusion and outcomes in trauma. J Surg Res. 2018;227:52-59. doi:10.1016/j.jss.2018.02.013

9.         Cantle PM, Cotton BA. Prediction of Massive Transfusion in Trauma. Crit Care Clin. 2017;33(1):71-84. doi:10.1016/j.ccc.2016.08.002

10.       Cannon CM, Braxton CC, Kling-Smith M, Mahnken JD, Carlton E, Moncure M. Utility of the shock index in predicting mortality in traumatically injured patients. J Trauma – Inj Infect Crit Care. 2009;67(6):1426-1430. doi:10.1097/TA.0b013e3181bbf728

11.       Bhat A, Podstawczyk D, Walther BK, et al. Toward a hemorrhagic trauma severity score: Fusing five physiological biomarkers. J Transl Med. 2020;18(1):1-17. doi:10.1186/s12967-020-02516-4

12.       Ageron FX, Coats TJ, Darioli V, Roberts I. Validation of the BATT score for prehospital risk stratification of traumatic haemorrhagic death: usefulness for tranexamic acid treatment criteria. Scand J Trauma Resusc Emerg Med. 2021;29(1):1-9. doi:10.1186/s13049-020-00827-5

13.       Yücel N, Lefering R, Maegele M, et al. Trauma Associated Severe Hemorrhage (TASH)-score: Probability of mass transfusion as surrogate for life threatening hemorrhage after multiple trauma. J Trauma – Inj Infect Crit Care. 2006;60(6):1228-1236. doi:10.1097/01.ta.0000220386.84012.bf

14.       Vandromme MJ, Griffin RL, Kerby JD, McGwin G, Rue LW, Weinberg JA. Identifying risk for massive transfusion in the relatively normotensive patient: Utility of the prehospital shock index. J Trauma – Inj Infect Crit Care. 2011;70(2):384-390. doi:10.1097/TA.0b013e3182095a0a

15.       Schroll R, Swift D, Tatum D, et al. Accuracy of shock index versus ABC score to predict need for massive transfusion in trauma patients. Injury. 2018;49(1):15-19. doi:10.1016/j.injury.2017.09.015

16.       Rainer TH, Ho AMH, Yeung JHH, et al. Early risk stratification of patients with major trauma requiring massive blood transfusion. Resuscitation. 2011;82(6):724-729. doi:10.1016/j.resuscitation.2011.02.016

17.       Maegele M, Spinella PC, Schöchl H. The acute coagulopathy of trauma: Mechanisms and tools for risk Stratification. Shock. 2012;38(5):450-458. doi:10.1097/SHK.0b013e31826dbd23

18.       Duque P, Mora L, Levy JH, Schöchl H. Pathophysiological response to trauma-induced coagulopathy: A comprehensive review. Anesth Analg. 2020;XXX(Xxx):654-664. doi:10.1213/ANE.0000000000004478

19.       George MJ, Aroom KR, Wade CE, Cox CS, Gill BS. A Novel Platelet Function Assay for Trauma. J Surg Res. 2020;246:605-613. doi:10.1016/j.jss.2019.09.052

20.       Charbit J, Lakhal K, Deras P, et al. Influence of surgical bleeding on the relationship between admission coagulopathy and risk of massive transfusion: lesson from 704 severe trauma patients. Vox Sang. 2016;111(2):151-160. doi:10.1111/vox.12401

21.       Lieurance R, Benjamin JB, Rappaport WD. Blood loss and transfusion in patients with isolated femur fractures. J Orthop Trauma. 1992;6(2):175-179. doi:10.1097/00005131-199206000-00007

22.       Lack WD, Crist BD, Seymour RB, Harvin W, Karunakar MA. Effect of Tranexamic Acid on Transfusion: A Randomized Clinical Trial in Acetabular Fracture Surgery. J Orthop Trauma. 2017;31(10):526-530. doi:10.1097/BOT.0000000000000968

23.       Bigsby E, Acharya MR, Ward AJ, Chesser TJS. The Use of Blood Cell Salvage in Acetabular Fracture Internal Fixation Surgery. J Orthop Trauma. 2013;27(10):e230-e233. doi:10.1097/BOT.0b013e3182877684

24.       Wadhwa H, Chen MJ, Tigchelaar SS, Bellino MJ, Bishop JA, Gardner MJ. Hypotensive Anesthesia does not reduce Transfusion Rates during and after Acetabular Fracture Surgery. Injury. 2021;52(7):1783-1787. doi:10.1016/j.injury.2021.03.059

25.       Chee YL, Crawford JC, Watson HG, Greaves M. Guidelines on the assessment of bleeding risk prior to surgery or invasive procedures: British Committee for Standards in Haematology. Br J Haematol. 2008;140(5):496-504. doi:10.1111/j.1365-2141.2007.06968.x

26.    Spyropoulos AC, Brohi K, Caprini J, et al. Scientific and Standardization Committee Communication: Guidance document on the periprocedural management of patients on chronic oral anticoagulant therapy: Recommendations for standardized reporting of procedural/surgical bleed risk and patient-specific thromboembolic risk. J Thromb Haemost JTH. 2019;17(11):1966-1972. doi:10.1111/jth.14598