What is new in the blood bank for trauma resuscitation

Five Decades of Trauma Anesthesiology

We present a brief history of the scientific and educational development of trauma anesthesiology. Key milestones from the past 50 years are noted, as well as the current standing of the subspecialty and prospects for the future.

Platelet Transfusion for Trauma Resuscitation

Purpose of Review

To review the role of platelet transfusion in resuscitation for trauma, including normal platelet function and alterations in behavior following trauma, blood product transfusion ratios and the impact of platelet transfusion on platelet function, platelet function assays, risks of platelet transfusion and considerations for platelet storage, and potential adjunct therapies and synthetic platelets.

Recent Findings

Platelets are a critical component of clot formation and breakdown following injury, and in addition to these hemostatic properties, have a complex role in vascular homeostasis, inflammation, and immune function. Evidence supports that platelets are activated following trauma with several upregulated functions, but under conditions of severe injury and shock are found to be impaired in their hemostatic behaviors. Platelets should be transfused in balanced ratios with red blood cells and plasma during initial trauma resuscitation as this portends improved outcomes including survival. Multiple coagulation assays can be used for goal-directed resuscitation for traumatic hemorrhage; however, these assays each have drawbacks in terms of their ability to measure platelet function. While resuscitation with balanced transfusion ratios is supported by the literature, platelet transfusion carries its own risks such as bacterial infection and lung injury. Platelet supply is also limited, with resource-intensive storage requirements, making exploration of longer-term storage options and novel platelet-based therapeutics attractive. Future focus on a deeper understanding of the biology of platelets following trauma, and on optimization of novel platelet-based therapeutics to maintain hemostatic effects while improving availability should be pursued.

Summary

While platelet function is altered following trauma, platelets should be transfused in balanced ratios during initial resuscitation. Severe injury and shock can impair platelet function, which can persist for several days following the initial trauma. Assays to guide resuscitation following the initial period as well as storage techniques to extend platelet shelf life are important areas of investigation.

The Israel Defense Forces experience with freeze-dried plasma for the resuscitation of traumatized pediatric patients

BACKGROUND

With the growing recognition of the disadvantages of crystalloid- and colloid-based resuscitation and the advantages of using blood products as the preferred resuscitation fluid, the Israel Defense Forces Medical Corps (IDF-MC) adopted plasma as the primary volume resuscitation regimen in 2013. While data are accumulating for prehospital plasma transfusion, little to no data exist regarding using plasma as a prehospital resuscitation fluid for traumatized pediatric patients.

METHODS

All patients treated by the IDF-MC personnel are recorded in the IDF Trauma Registry, a unique prehospital trauma registry. All patients treated by the IDF advanced life support providers with FDP at the point of injury between April 2013 and June 2018 who were younger than 18 years at the time of injury were included.

RESULTS

Six hundred seventy-nine children were treated by IDF medical providers, of whom 33 (5%) were identified in the IDF Trauma Registry as having received FDP at the point of injury. Most patients (80%) were treated for penetrating injuries. Most patients received one plasma unit. Fifty-four percent of the patients were also treated by Tranexamic Acid (TXA) and 48% were transfused with crystalloids. In 33% of patients, additional life-saving interventions were performed.

CONCLUSION

While the ideal resuscitation fluid for the pediatric population remains to be determined, it seems reasonable to pursue a similar approach to that of applied that for adults. In the IDF-MC, the resuscitation fluid of choice for trauma patients in hemorrhagic shock is freeze-dried plasma transfused at the point of injury. The current study demonstrates the feasibility of FDP administration in the prehospital scenario for injured children and further supports the growing confidence in the use of FDP for the treatment of pediatric trauma patients.

LEVEL OF EVIDENCE

Retrospective descriptive study, level IV.

Low End-Tidal Carbon Dioxide at the Onset of Emergent Trauma Surgery Is Associated With Nonsurvival: A Case Series

BACKGROUND

End-tidal carbon dioxide (EtCO2) is a valuable marker of the return of adequate circulation after cardiac arrest due to medical causes. Previously, the prognostic value of capnography in trauma has been studied among limited populations in prehospital and emergency department settings. We aimed to investigate the relationship between early intraoperative EtCO2 and nonsurvival of patients undergoing emergency surgery at a level 1 academic trauma center as a case series. If there is a threshold below which survival was extremely unlikely, it might be useful in guiding decision-making in the early termination of futile resuscitative efforts.

METHODS

After institutional review board approval, a data set was created to investigate the relationship between EtCO2 values at the onset of emergent trauma surgery and nonsurvival. Patients who were admitted and transferred to the operating room (OR) directly from a resuscitation bay were identified using the Ryder Center trauma registry (October 1, 2013, to June 30, 2016). Electronic records from the hospital's anesthesia information management system were queried to identify the matching anesthesia records. The maximum EtCO2 values within 5 and 10 minutes of the onset of mechanical ventilation in the OR were determined for patients undergoing general anesthesia with mechanical ventilation. Patients were divided into 2 groups: those who were discharged from the hospital alive (survivors) and those who died in the hospital before discharge (nonsurvivors). The threshold EtCO2 giving a positive predictive value of 100% for in-hospital mortality was determined from a graphical analysis of the data. Association of determined threshold and mortality was analyzed using the 2-tailed Fisher exact test.

RESULTS

There were 1135 patients who met the inclusion criteria. Within the first 5 minutes of the onset of mechanical ventilation in the OR, if the maximum EtCO2 value was ≤20 mm Hg, hospital mortality was 100% (21/21, 95% binomial confidence interval, 83.2%-100%).

CONCLUSIONS

A maximum EtCO2 ≤20 mm Hg within 5 minutes of the onset of mechanical ventilation in the OR may be useful in decision-making related to the termination of resuscitative efforts during emergent trauma surgery. However, a large-scale study is needed to establish the statistical reliability of this finding before potential adoption.

Comparison of haemostatic function of PAS-C-platelets vs. plasma-platelets in reconstituted whole blood using impedance aggregometry and thromboelastography

BACKGROUND AND OBJECTIVES

There are concerns about the haemostatic function of platelets stored in platelet additive solution (PAS). Aim of this study was to compare the haemostatic function of PAS-C-platelets to plasma-platelets in reconstituted whole blood.

MATERIALS AND METHODS

In our experiment, whole blood was reconstituted with red blood cells, solvent-detergent (SD) plasma and either PAS-C-platelets or plasma-platelets (n = 7) in a physiological ratio. On storage days 2, 5, 8 and 13, the agonist-induced aggregation (multiple electrode aggregometry), clot formation (thromboelastography) and agonist-induced CD62P responsiveness (flow cytometry) were measured.

RESULTS

Samples with PAS-C-platelets showed significantly lower aggregation than plasma-platelets when induced with adenosine diphosphate, -6 U (95% confidence interval: -8; -4) or thrombin receptor-activating protein, -15 U (-19; -10). Also when activated with collagen and ristocetin, the PAS-C-platelets showed less aggregation, although not statistically significant. All samples with PAS-C-platelets showed significantly lower agonist-induced CD62P responsiveness than samples with plasma-platelets. However, there was no difference regarding all TEG parameters.

CONCLUSION

Our findings demonstrate that the function - aggregation and CD62P responsiveness - of PAS-C-platelets in reconstituted whole blood is inferior to that of plasma-platelets, which may have implications in the setting of massive transfusions.

Haemotherapy algorithm for the management of trauma-induced coagulopathy: an Australian perspective

PURPOSE OF REVIEW

Recent advances in the understanding of the pathophysiological processes associated with traumatic haemorrhage and trauma-induced coagulopathy have resulted in improved outcomes for seriously injured trauma patients. However, a significant number of trauma patients still die from haemorrhage. This article reviews the various transfusion strategies utilized in the management of traumatic haemorrhage and describes the major haemorrhage protocol (MHP) strategy employed by an Australian trauma centre.

RECENT FINDINGS

Few topics in trauma resuscitation incite as much debate and controversy as to what constitutes the 'ideal' MHP. There is a widespread geographical and institutional variation in clinical practice. Three strategies are commonly utilized; fixed ratio major haemorrhage protocol (FRMHP), viscoelastic haemostatic assay (VHA)-guided MHP and hybrid MHP. The majority of trauma centres utilize an FRMHP and there is high-level evidence to support the use of high blood product ratios. It can be argued that the FRMHP is too simplistic to be applied to all trauma patients and that the use of VHA-guided MHP with predominant factor concentrate transfusion can allow rapid individualized interventions. In between these two strategies is a hybrid MHP, combining early FRMHP with subsequent VHA-guided transfusion.

SUMMARY

There are advantages and disadvantages to each of the various MHP strategies and the evidence base to support one above another with any certainty is lacking at this time. One strategy cannot be considered superior to the other and the choice of MHP is dependent on interpretation of the current literature and local institutional logistical considerations. A number of exciting studies are currently underway that will certainly increase the evidence base and help inform clinical practice.

Liquid plasma use during "super" massive transfusion protocol

BACKGROUND

A massive transfusion protocol (MTP) presents a logistical challenge for most blood banks and trauma centers. We compare the ratio of packed red blood cells (PRBC) and plasma transfused over serial time points in those requiring MTP (10-30 U PRBC/24 h) to those requiring "super" MTP (S-MTP; >30 U PRBC/24 h) and test the hypothesis that changes in allocation of blood products with use of readily transfusable liquid plasma (LP) improves the ratio of PRBC and plasma during S-MTP.

MATERIALS AND METHODS

All transfused trauma patients (n = 1305) from January 01, 2009-April, 03, 2015 were reviewed. PRBC:plasma ratio was compared for MTP (n = 277) and S-MTP (n = 61) patients, before and after the availability of LP at our institution. Data are reported as mean ± standard deviation or median (interquartile range).

RESULTS

Age was 41 ± 19 y, 52% blunt mechanism, injury severity score 32 ± 16, and 46.3% mortality. In 24 h, requirements were 17 (14) U PRBC and 10 (11) U plasma, with a PRBC:plasma of 1.6 (0.8). Within the first hour, PRBC:plasma for S-MTP versus MTP was 2.1:1 versus 1.7:1 (P = 0.017). With LP, S-MTP patients received significantly lower PRBC:plasma at the first hour (P < 0.001). Before institutional changes, PRBC:plasma positively correlated with PRBC transfused at hour 1 (r = 0.410, R(2) = 0.168, P < 0.001); after institutional changes and the advent of LP, there was no correlation (r = 0.177, R(2) = 0.031, P = 0.219).

CONCLUSIONS

Within the first hour of transfusion, units of PRBC transfused positively correlated with PRBC:plasma, and patients receiving S-MTP had higher PRBC:plasma than those receiving MTP. Changes in our institution's MTP protocol to include LP improved the early PRBC:plasma transfused in patients requiring S-MTP.