Rotational thromboelastometry values across age groups in all trauma patients presenting to a level 1 trauma centre: An observational study

OBJECTIVES

To describe rotational thromboelastometry (ROTEM) values (FIBTEM A5, EXTEM A5 and EXTEM CT) across age groups and assess for a statistical trend; and to determine whether any trend in ROTEM values is affected by severity of injury and packed red blood cells (PRBC) requirement.

METHODS

Retrospective observational study at a level 1 trauma centre in Queensland, Australia. A total of 1601 consecutive trauma patients presenting to the ED. ROTEM data described included FIBTEM A5, EXTEM A5 and EXTEM CT. These values are described by age group (≤30 years, 31-45 years, 46-60 years, 61-75 years and >75 years), Injury Severity Score (ISS) category (<12, ≥12, <25 and ≥25) and number of PRBCs transfused in the first 24 h of admission (0 units, 1-4 units, 5-9 units and ≥10 units).

RESULTS

The median age of participants was 37 years (interquartile range [IQR] 25-54 years), with 48.2% of patients had severe trauma (ISS >12) and 13.2% receiving at least one unit of PRBC in the first 24 h of admission. Median (IQR) values for FIBTEM A5, EXTEM A5 and EXTEM CT were 13 mm (10-16 mm), 45 mm (40-49 mm) and 62 s (56-71 s), respectively. A test for trend over progressive age groups showed an increase in FIBTEM A5 (P < 0.001) and EXTEM A5 values (P < 0.001) and a decrease in EXTEM CT values (P < 0.001).

CONCLUSION

The present study demonstrated a pattern of increasing coagulability, as defined by ROTEM, with increasing age group in trauma patients, even among the severely injured. Further investigation is required to determine the clinical impact of these findings on both the ROTEM-guided management and longitudinal outcomes of these patients and whether an age-specific approach is beneficial.

Empiric tranexamic acid use provides no benefit in urgent orthopedic surgery following injury

Background

Orthopedic literature has demonstrated a significant decrease in postoperative transfusion requirements when tranexamic acid (TXA) was given during elective joint arthroplasty. The purpose of this study was to evaluate the empiric use of TXA in semi-urgent orthopedic procedures following injury. We hypothesized that TXA would be associated with increased rates of venous thromboembolic events (VTE) and have no effect on transfusion requirements.

Methods

Patients who empirically received TXA during a semi-urgent orthopedic surgery following injury (TXA+) were matched using propensity scoring to historical controls (CONTROL) who did not receive TXA. Outcomes included VTE within 6 months of injury and packed red blood cell utilization. Multivariable logistic regression and generalized linear modeling were used to determine odds of VTE and transfusion.

Results

200 patients were included in each group. There was no difference in mortality between groups. TXA+ patients did not have an increase in VTE events (OR 0.680, 95% CI 0.206 to 2.248). TXA+ patients had a significantly higher odds of being transfused during their hospital stay (OR 2.175, 95% CI 1.246 to 3.797) and during the index surgery (increased 0.95 units (SD 0.16), p<0.0001). Overall transfusion was also significantly higher in the TXA+ group (p=0.0021).

Conclusion

Empiric use of TXA in semi-urgent orthopedic surgeries did not increase the odds of VTE. Despite the elective literature, TXA administration did not associate with less transfusion requirements. A properly powered, prospective, randomized trial should be designed to elucidate the risks and benefits associated with TXA use in this setting.

Level of evidence

Level IV.

Clinical Characteristics and Risk Factors for Early versus Late Pulmonary Embolism in Trauma Patients: A Retrospective, Observational Study

Background

We sought to evaluate the clinical characteristics and risk factors for early versus late pulmonary embolism (PE) in trauma patients.

Methods

This was a retrospective analysis of injured patients who presented with a confirmed PE between 2013 and 2019. Data were analysed and compared for patients with early PE (≤4 days) versus late PE (>4 days post-trauma).

Results

The study included 82 consecutive trauma patients with confirmed diagnosis of PE. The mean age of patients was 42.3 ± 16.2 years. The majority were males (79.3%) and the median time from injury to PE was 10 days. Of the PE cases, 24 (29.3%) had early PE, while 58 (70.7%) had late PE. The early PE group had higher rates of surgical intervention within 24 hours of admission than the late PE group (p = 0.001). Also, the rate of sub-segmental thrombi was significantly higher in the early PE group (p = 0.01). The late PE group sustained more moderate-to-severe injuries ie, GCS ED <13 (p = 0.03) and the median time from injury to PE diagnosis was 15 days (p = 0.001). After adjusting for the potential covariates, surgery within 24 hours of admission [adjusted odds ratio 37.58 (95% confidence interval 3.393-416.20), p = 0.003] was found to be significant independent predictor of early PE in trauma patients.

Conclusion

One-third of post-trauma PEs occurs early after trauma and the surgical intervention within the first 24 hours of admission is a major risk factor. A prospective study is needed to develop an objective risk assessment for the prevention and detection of early and late PE post-trauma.

The Role of TEG and ROTEM in Damage Control Resuscitation

ABSTRACT

Trauma-induced coagulopathy is associated with very high mortality, and hemorrhage remains the leading preventable cause of death after injury. Directed methods to combat coagulopathy and attain hemostasis are needed. The available literature regarding viscoelastic testing, including thrombelastography (TEG) and rotational thromboelastometry (ROTEM), was reviewed to provide clinically relevant guidance for emergency resuscitation. These tests predict massive transfusion and developing coagulopathy earlier than conventional coagulation testing, within 15 min using rapid testing. They can guide resuscitation after trauma, as well. TEG and ROTEM direct early transfusion of fresh frozen plasma when clinical gestalt has not activated a massive transfusion protocol. Reaction time and clotting time via these tests can also detect clinically significant levels of direct oral anticoagulants. Slowed clot kinetics suggest the need for transfusion of fibrinogen via concentrates or cryoprecipitate. Lowered clot strength can be corrected with platelets and fibrinogen. Finally, viscoelastic tests identify fibrinolysis, a finding associated with significantly increased mortality yet one that no conventional coagulation test can reliably detect. Using these parameters, guided resuscitation begins within minutes of a patient's arrival. A growing body of evidence suggests this approach may improve survival while reducing volumes of blood products transfused.

Thromboelastography for the Orthopaedic Surgeon

Evaluation of coagulation is vital in the care of the orthopaedic patients, particularly in the subspecialties of trauma, spine, arthroplasty, and revision surgery resulting from blood loss and coagulopathies. Although conventional tests (prothrombin time/international normalized ratio, activated partial thromboplastin time, platelet count, and fibrinogen) are most commonly used, others like thromboelastography (TEG) are also available to the orthopaedic surgeons. TEG is a blood test developed in the 1950s, which provides a snapshot of a patient's coagulation profile by evaluating clot formation and lysis. Recently, TEG has been used to assess traumatic coagulopathy. The coagulation parameters measured by the TEG are reaction time (R-time), time to reach a certain clot strength (K-value), speed of fibrin build up (α-angle), maximum clot amplitude, and percentage decrease of clot in 30 minutes (LY30). Using these values, traumatologists have developed a better, faster, and more accurate overview of a patient's resuscitation and more successfully direct blood product use. However, many orthopaedic surgeons-despite performing surgical procedures that risk notable blood loss and postoperative clotting complications-are unaware of the existence of the TEG blood test and the critical information it provides. Increasing awareness of the TEG among orthopaedic surgeons could have a notable effect on numerous aspects of musculoskeletal care.

Using rotational thromboelastometry clot firmness at 5 minutes (ROTEM® EXTEM A5) to predict massive transfusion and in-hospital mortality in trauma: a retrospective analysis of 1146 patients

Viscoelastic assays such as TEG^® and ROTEM^® are increasingly used to guide transfusion of blood products. The EXTEM assay maximum clot firmness (MCF) is a ROTEM measure available after 25–29 min used to guide early decisions. EXTEM A10, the clot firmness at 10 min, is an accepted early surrogate, but investigators differ on whether A5, the clot firmness at 5 min, is acceptable. We re‐examined this in a retrospective observational analysis of 1146 trauma patients in one centre who had ROTEM data recorded. A5 and A10 both correlated well with maximum clot firmness, with Pearson coefficients of r = 0.92 and r = 0.96, respectively. The correlations of A5, A10 and maximum clot firmness with requirement for massive transfusion were all similarly high, with c‐stats of 0.87, 0.89 and 0.90, respectively. The correlations with mortality were also similar but weaker, with c‐stats of 0.67, 0.69 and 0.69, respectively. Using a previously validated cut‐off of A5 < 35 mm to predict massive transfusion gave a sensitivity of 95%, specificity 83%, positive predictive value 9.3% and negative predictive value 100%. Using a value of A5 < 29 mm, for a pragmatic positive predictive value of 20%, gave a sensitivity of 67%, specificity 95% and negative predictive value 99%. Whether aiming for a high sensitivity or a strong predictive value, A5 was non‐inferior to A10 and actually missed fewer cases needing massive transfusion. A5 has similar utility to both A10 and maximum clot firmness as an early measure of clot firmness, and a low A5 value is strongly predictive of the need for massive transfusion.

Outcomes after concomitant traumatic brain injury and hemorrhagic shock: A secondary analysis from the Pragmatic, Randomized Optimal Platelets and Plasma Ratios trial

BACKGROUND

Often the clinician is faced with a diagnostic and therapeutic dilemma in patients with concomitant traumatic brain injury (TBI) and hemorrhagic shock (HS), as rapid deterioration from either can be fatal. Knowledge about outcomes after concomitant TBI and HS may help prioritize the emergent management of these patients. We hypothesized that patients with concomitant TBI and HS (TBI + HS) had worse outcomes and required more intensive care compared with patients with only one of these injuries.

METHODS

This is a post hoc analysis of the Pragmatic, Randomized Optimal Platelets and Plasma Ratios (PROPPR) trial. TBI was defined by a head Abbreviated Injury Scale score greater than 2. HS was defined as a base excess of -4 or less and/or shock index of 0.9 or greater. The primary outcome for this analysis was mortality at 30 days. Logistic regression, using generalized estimating equations, was used to model categorical outcomes.

RESULTS

Six hundred seventy patients were included. Patients with TBI + HS had significantly higher lactate (median, 6.3; interquartile range, 4.7-9.2) compared with the TBI group (median, 3.3; interquartile range, 2.3-4). TBI + HS patients had higher activated prothrombin times and lower platelet counts. Unadjusted mortality was higher in the TBI + HS (51.6%) and TBI (50%) groups compared with the HS (17.5%) and neither group (7.7%). Adjusted odds of death in the TBI and TBI + HS groups were 8.2 (95% confidence interval, 3.4-19.5) and 10.6 (95% confidence interval, 4.8-23.2) times higher, respectively. Ventilator, intensive care unit-free and hospital-free days were lower in the TBI and TBI + HS groups compared with the other groups. Patients with TBI + HS or TBI had significantly greater odds of developing a respiratory complication compared with the neither group.

CONCLUSION

The addition of TBI to HS is associated with worse coagulopathy before resuscitation and increased mortality. When controlling for multiple known confounders, the diagnosis of TBI alone or TBI+HS was associated with significantly greater odds of developing respiratory complications.

LEVEL OF EVIDENCE

Prognostic study, level II.

Timing of pulmonary embolisms in femur fracture patients: Incidence and outcomes

BACKGROUND

Femur fracture is a well-recognized risk factor for pulmonary embolism (PE). Despite recent reports of early PE after major trauma, the incidence and outcomes of PE in femur fracture patients are unknown. The aims of the study were to determine the incidence of PE after a femur fracture and to evaluate its timing and clinical significance.

METHODS

We included all consecutive adult patients (≥18 years old) with femur fracture admitted to our emergency department from January 2010 to December 2014 who underwent subsequent PE computed tomography within 72 hours. Of 453 stable patients, 28 with a confirmed diagnosis of acute PE were compared against those without PE.

RESULTS

Of 1,301 femur fracture patients who presented at our hospital, 453 were included in our present analysis, of whom 28 developed PE (2.2%). Proximal PE, defined as emboli located within the main or lobar arteries, constituted 78.6% and subsegmental PE constituted 21.4% of these 28 cases. The femur fracture sites were mainly intertrochanteric (50.3%) and the neck (43.9%). The median interval from injury to computed tomography was 13.0 hours (IQR, 9.0-24.0 hours). PE was detected in 57.1% (16 of 28) of patients in the first 24 hours after injury and in 89.3% (25 of 28) in the first 48 hours. Overall mortality was 0.7%, and no patient in the early PE group died of their injury.

CONCLUSION

PE arises in femur fracture patients in the immediate period following injury and shows an incidence somewhat higher than commonly appreciated in other trauma events but is not fatal.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level III.

Point of Care Assessment of Coagulation

Disorders of hemostasis can be difficult to fully elucidate but can severely affect patient outcome. The optimal therapy for coagulopathies is also not always clear. Point of care (POC) testing in veterinary medicine can assist in the diagnosis of hemostatic disorders and also direct treatment. Advantages of POC testing include rapid turnaround times, ease of use, and proximity to the patient. Disadvantages include differences in analytic performance compared with reference laboratory devices, the potential for operator error, and limited test options per device. Conventional coagulation tests such as prothrombin time, activated partial thromboplastin time, and activated clotting time can be measured by POC devices and can accurately diagnose hypocoagulability, but they cannot detect hypercoagulability or disorders of fibrinolysis. Viscoelastic POC coagulation testing more accurately evaluates in vivo coagulation, and can detect hypocoagulability, hypercoagulability, and alterations in fibrinolysis. POC platelet function testing methodologies can detect platelet adhesion abnormalities including von Willebrand disease, and can be used to monitor the efficacy of antiplatelet drugs. It is unlikely that a single test would be ideal for assessing the complete coagulation status of all patients; therefore, the ideal combination of tests for a specific patient needs to be determined based on an understanding of the underlying disease, and protocols must be standardized to minimize interoperator and interinstitutional variability.

Thromboelastography: A Practice Summary for Nurse Practitioners Treating Hemorrhage

Nurse practitioners may manage patients with coagulopathic bleeding which can lead to life-threatening hemorrhage. Routine plasma-based tests such as prothrombin time and activated partial thromboplastin time are inadequate in diagnosing hemorrhagic coagulopathy. Indiscriminate administration of fresh frozen plasma, platelets or cryoprecipitate for coagulopathic states can be extremely dangerous. The qualitative analysis that thromboelastography provides can facilitate the administration of the right blood product, at the right time, thereby permitting the application of goal-directed therapy for coagulopathic intervention application and patient survival.

Factors associated with pulmonary embolism within 72 hours of admission after trauma: a multicenter study

BACKGROUND

Recent studies using thromboelastography indicate that patients are at risk for hypercoagulability early after injury. Pulmonary embolism (PE) is also well known to cause significant morbidity and mortality after injury and can occur within 72 hours of admission (early PE). Despite this risk, prophylactic anticoagulation is often delayed in patients with certain injuries due to concerns about bleeding.

STUDY DESIGN

This was a retrospective study of injured patients with a PE from 2007 to 2013 at 3 level I trauma centers. Data collected included patient demographics, injury patterns, length of stay, timing of prophylaxis for deep vein thrombosis (DVT), and diagnosis of PE. Patients with early PE (≤ 3 days) were compared with those with late PE (>3 days) using bivariate and multivariable analysis.

RESULTS

A total of 54,964 patients were admitted to the 3 centers during the study period, and 144 (0.26%) were diagnosed with a PE. Eleven were excluded from the study due to a lack of critical data, leaving 133 patients (43% early PE). Factors associated with early PE included long bone fractures in the lower extremity and an Abbreviated Injury Score (AIS) Extremity ≥ 3. Higher Injury Severity Score, severe chest and head trauma (AIS ≥ 3), and not receiving DVT prophylaxis within 48 hours of hospital admission were not associated with early PE.

CONCLUSIONS

Early PE is a significant clinical entity occurring in nearly half the patients who suffered a PE. Early PE is associated with long bone fractures and severe extremity trauma, but not severe thoracic injury. Timing of prophylactic anticoagulation had no impact on early PE. If further studies confirm this incidence of unsuspected early PE, all admitted trauma patients should be assessed for a hypercoagulable state after injury.