Resuscitation and transfusion management in trauma patients: emerging concepts

Multi-objective location-distribution optimization in blood supply chain: an application in Turkiye

PURPOSE

Blood donors are crucial in maintaining the blood supply chain. This study aims to improve the location and distribution of blood donation centers by focusing on two main objectives: minimizing costs and maximizing quality. Minimizing costs includes setting up and transporting blood efficiently while maximizing quality to ensure that blood products are delivered to hospitals promptly and in the right quantities.

METHODS

A multi-objective mathematical model is proposed to address the placement of both fixed and mobile blood donation centers. The first objective focuses on minimizing the costs of setting up centers and transporting blood. The second objective aims to maximize quality by ensuring timely deliveries and meeting hospitals' blood demand. The model utilizes real-world traffic and blood donation data from urban settings to simulate its effectiveness and applicability in practice. The model uses the ε constraint method to optimize both objectives simultaneously.

RESULTS

The model was tested in various scenarios, optimizing cost and quality separately. The algorithm determined the ideal locations for blood donation centers to meet demand by exploring different options. It also accounted for factors that reduce quality, such as delayed deliveries and product returns, and showed that these issues could be minimized.

CONCLUSION

This study highlights the need to balance cost and quality when determining the locations of blood donation centers. Using the ε constraint method, the model successfully optimized both objectives, offering valuable insights for improving the efficiency and effectiveness of blood donation operations.

Blood management practices during rapid transfer of urgent trauma patients pre- and post-implementation of ROTEM®-guided transfusion

Objective

The ‘Red Blanket’ protocol fast tracks trauma patients with severe blood loss to the designated trauma operating theatre directly from the hospital helipad or Emergency Department. This study aimed to assess the impact of patient blood management (PBM) strategies on severely injured trauma patients treated under the ‘Red Blanket’ protocol at a quaternary referral hospital.

Methods

This retrospective review was conducted on all urgent trauma cases that were treated under the ‘Red Blanket’ protocol in a ten-year period between January 2007 and December 2017. The use of blood products and patient outcomes was compared between the 3.5-year periods pre- and post-ROTEM® implementation on 30th June 2014 (Jan 2011-June 2014 versus July 2014-Dec 2017).

Results

During the study period, 120 trauma patients were treated under the ‘Red Blanket’ protocol at our institution. Intention to treat analysis showed a reduction in fresh frozen plasma usage following the introduction of ROTEM®-guided transfusion. Furthermore, subgroup analysis suggested reduced blood product usage in patients who survived.

Conclusions

Patient blood management is a coordinated package of systems and tools, including education, patient logistics, anaemia management, intraoperative cell salvage, rotational thromboelastometry and massive transfusion protocols that together conserve blood products and improve outcomes. The implementation of ROTEM®-guided transfusion demonstrated a reduction in fresh frozen plasma usage.

Viscoelastic Hemostatic Assays: A Primer on Legacy and New Generation Devices

Viscoelastic hemostatic assay (VHAs) are whole blood point-of-care tests that have become an essential method for assaying hemostatic competence in liver transplantation, cardiac surgery, and most recently, trauma surgery involving hemorrhagic shock. It has taken more than three-quarters of a century of research and clinical application for this technology to become mainstream in these three clinical areas. Within the last decade, the cup and pin legacy devices, such as thromboelastography (TEG^® 5000) and rotational thromboelastometry (ROTEM^® delta), have been supplanted not only by cartridge systems (TEG^® 6S and ROTEM^® sigma), but also by more portable point-of-care bedside testing iterations of these legacy devices (e.g., Sonoclot^®, Quantra^®, and ClotPro^®). Here, the legacy and new generation VHAs are compared on the basis of their unique hemostatic parameters that define contributions of coagulation factors, fibrinogen/fibrin, platelets, and clot lysis as related to the lifespan of a clot. In conclusion, we offer a brief discussion on the meteoric adoption of VHAs across the medical and surgical specialties to address COVID-19-associated coagulopathy.

A survey of emergency and critical care veterinarians regarding IV fluid bolus therapy and monitoring practices in small animals

OBJECTIVE

To determine how veterinary emergency and critical care clinicians define IV fluid bolus therapy (FBT) and what constitutes a positive response to a fluid bolus.

DESIGN

Online survey of 222 emergency and critical care veterinarians between December 17, 2018, and March 1, 2019.

INTERVENTIONS

An online survey was provided to diplomates of the American College of Veterinary Emergency and Critical Care (ACVECC), residents of ACVECC-approved training programs, as well as house officers and emergency clinicians of a corporate multicenter emergency and specialty care veterinary hospital. The survey investigated the administration of various crystalloid, colloid, and blood products for FBT, as well as expected physiological responses.

MEASUREMENTS AND MAIN RESULTS

The majority of respondents considered balanced isotonic crystalloids appropriate for FBT (220/222 [99.1%]). Respondents showed greater variability in acceptance of 0.9% sodium chloride (105/222 [47.30%]), hypertonic (3-7%) sodium chloride (131/222 [59.01%]), and hydroxyethyl starch solutions (90/222 [40.54%]). Most respondents did not consider physiological plasma (44/222 [19.82%]) an appropriate choice. The most commonly used parameters for monitoring FBT responses were heart rate (220/222 [99.10%]), blood pressure (217/222 [97.75%]), capillary refill time (192/222 [86.49%]), lactate (181/222 [81.53%]), pulse pressure (151/222 [68.02%]), and rectal temperature (145/222 [65.32%]). The majority of respondents perceived that 0-20% (165/222 [74.32%]) of hypotensive patients are nonresponsive to FBT.

CONCLUSIONS

Small animal emergency and critical care clinicians favored balanced isotonic electrolyte solutions and hypertonic sodium chloride solutions for FBT over other options. When monitoring responses to FBT, heart rate, blood pressure, capillary refill time, and plasma lactate were among the most commonly monitored parameters, and there was a lack of familiarity with others. Despite the widespread use of FBT, these findings outline the need for further prospective clinical trials regarding the ideal fluid type and rate, as well as the appropriate responses to FBT.

Advances in anesthetic and obstetric management of patients with placenta accreta spectrum

PURPOSE OF REVIEW

The incidence of placenta accreta spectrum is increasing and it is a leading cause of peripartum hysterectomy and massive postpartum hemorrhage. The purpose of the present article is to provide a contemporary overview of placenta accreta spectrum pertinent to the obstetric anesthesiologist.

RECENT FINDINGS

Recent changes in the terminology used to report invasive placentation were proposed to clarify diagnostic criteria and guidelines for use in clinical practice. Reduced morbidity is associated with scheduled preterm delivery in a center of excellence using a multidisciplinary team approach. Neuraxial anesthesia as a primary technique is increasingly being used despite the known risk of major bleeding. The use of viscoelastic testing and endovascular interventions may aid hemostatic resuscitation and improve outcomes.

SUMMARY

Accurate diagnosis and early antenatal planning among team members are essential. Obstetric anesthesiologists should be prepared to manage a massive hemorrhage, transfusion, and associated coagulopathy. Increasingly, viscoelastic tests are being used to assess coagulation status and the ability to interpret these results is required to guide the transfusion regimen. Balloon occlusion of the abdominal aorta has been proposed as an intervention that could improve outcomes in women with placenta accreta spectrum, but high-quality safety and efficacy data are lacking.

Prothrombin Complex Concentrate-induced Disseminated Intravascular Coagulation Can Be Prevented by Coadministering Antithrombin in a Porcine Trauma Model

BACKGROUND

The risk of thromboembolic complications with prothrombin complex concentrates (PCCs) appears low when used for reversal of vitamin K antagonists but might be different in other indications (e.g., trauma). A difference in risk could arise from the plasma ratio of pro- versus anticoagulant proteins. This study used a porcine trauma model to investigate combined treatment with PCC and antithrombin. The hypothesis was that antithrombin can modulate prothrombotic effects and prevent adverse events of PCC.

METHODS

Nine treatment groups (n = 7 per group) were included: control (placebo), PCC (50 IU/kg), PCC plus antithrombin (three groups, with antithrombin doses of 12.5, 25, or 50 IU/kg), fibrinogen concentrate (100 mg/kg) plus PCC, fibrinogen concentrate plus PCC plus antithrombin dose of 50 IU/kg, tranexamic acid (15 mg/kg) plus fibrinogen concentrate plus PCC, and tranexamic acid plus fibrinogen concentrate plus PCC plus antithrombin dose of 50 IU/kg. In each group, bilateral femur fractures and thorax contusion were followed 60 min later by blunt liver injury. Study treatment was then administered, and animals were subsequently observed for 210 min.

RESULTS

Total blood loss (mean ± SD) was statistically significantly lower in all three PCC plus antithrombin groups (PCC plus antithrombin dose of 50 IU/kg, 672 ± 63 ml; PCC plus antithrombin dose of 25 IU/kg, 535 ± 72 ml; and PCC plus antithrombin dose of 12.5 IU/kg, 538 ± 50 ml) than in the PCC group (907 ± 132 ml), which in turn had statistically significantly reduced bleeding versus the control group (1,671 ± 409 ml). Signs of disseminated intravascular coagulation were apparent with PCC monotherapy, and early deaths occurred with fibrinogen concentrate plus PCC, attributable to pulmonary emboli. Antithrombin was protective against both of these effects: signs of disseminated intravascular coagulation were absent from the PCC plus antithrombin groups, and there were no early deaths in the group with fibrinogen concentrate plus PCC plus antithrombin dose of 50 IU/kg.

CONCLUSIONS

According to this trauma model, 50 IU/kg PCC increases the risk of disseminated intravascular coagulation and other thromboembolic complications, most notably when coadministered with fibrinogen concentrate. The addition of antithrombin appears to reduce this risk.

Impact of a goal-directed factor-based coagulation management on thromboembolic events following major trauma

BACKGROUND

A factor-based coagulation management following major trauma is recommended as standard of care by the European Trauma Treatment Guidelines. However, concerns about the thromboembolic risk of this approach are still prevalent. Our study therefore aims to assess if such a haemostatic management is associated with an increased risk for thromboembolic events.

METHODS

In this retrospective observational study carried out at the University Hospital Zurich we compared two three-year periods before (period 1: 2005-2007) and after (period 2: 2012-2014) implementation of a factor-based coagulation algorithm. We included all adult patients following major trauma primarily admitted to the University Hospital Zurich. Thromboembolic events were defined as a new in-hospital appearance of any peripheral thrombosis, arterial embolism, pulmonary embolism, stroke or myocardial infarction. A logistic regression was performed to investigate the association of thromboembolic events with possible confounders such as age, sex, specific Abbreviated Injury Scale (AIS) subgroups, allogeneic blood products, and the coagulation management.

RESULTS

Out of 1138 patients, 772 met the inclusion criteria: 344 patients in period 1 and 428 patients in period 2. Thromboembolic events were present in 25 patients (7.3%) of period 1 and in 42 patients (9.8%) of period 2 (raw OR 1.39, 95% CI 0.83 to 2.33, p = 0.21). Only AIS extremities (adjusted OR 1.26, 95% CI 1.05 to 1.52, p = 0.015) and exposure to allogeneic blood products (adjusted OR 2.39, 95% CI 1.33 to 4.30, p = 0.004) were independently associated with thromboembolic events in the logistic regression, but the factor-based coagulation management was not (adjusted OR 1.60, 95% CI 0.90-2.86, p = 0.11).

CONCLUSION

There is no evidence that a goal-directed, factor-based coagulation management is associated with an increased risk for thromboembolic events following major trauma.

Rapid testing of red blood cells, white blood cells and platelets in intensive care patients using the HemoScreen™ point-of-care analyzer

Acute major bleeding is a condition that can be encountered in critically ill patients and may require rapid transfusions. To evaluate the need for packed red blood cells (RBCs) and platelets (PLTs), it is important to have rapid test results for RBC/hemoglobin and PLTs. Recently, PixCell Medical (Yokneam Ilit, Israel) introduced the HemoScreen™, an automated hematology analyzer. It is a point-of-care device that uses single sample cuvettes and image analysis of RBCs, PLTs and white blood cells (WBCs), performing a five-part differential count. The HemoScreen™ is the first portable differential count instrument that uses image analysis. We compared the RBC, PLT, and WBC test results of the HemoScreen™ with the Sysmex XN device. In the study we analyzed 104 samples from the cardiothoracic, neuro and general intensive care units. The HemoScreen™ technique showed good precision, with total coefficient of variation of 1-2% for RBCs and 3-5% for PLTs. Deming correlations between the HemoScreen and the Sysmex XN instrument analyzer: (WBC_{HemoScreen™} = 1.061* WBC_Sysmex - 0.644; r = 0.995), RBC (RBC_{HemoScreen™} = 0.998* RBC_Sysmex + 0.049; r = 0.993) for WBC and (Platelets_{HemoScreen™} = 1.087* Platelets_Sysmex - 14.80; r = 0.994) for PLT. The HemoScreen™ device provided rapid and accurate test results to evaluate the need for RBC and PLT transfusion. This new technology is promising given that it allows the analysis of WBCs, RBCs, and PLTs further out in the healthcare organization compared with laboratory infrastructure based on traditional cell counters.

Comparison of two different coagulation algorithms on the use of allogenic blood products and coagulation factors in severely injured trauma patients: a retrospective, multicentre, observational study

Background

At the University Hospital Zurich (USZ) and the Cantonal Hospital of Lucerne (LUKS) an individualized goal-directed coagulation and transfusion algorithm was introduced and implemented before 2012 (Coagulation algorithm of the USZ: USZ-Alg; of the LUKS: LUKS-Alg). Main differences between both algorithms are: 1) A target haematocrit-range of 0.21–0.24 (USZ-Alg) vs. a lower haematocrit limit only (LUKS-Alg). 2) Blind coagulation-package in selected cases (LUKS-Alg only). 3) Factor XIII substitution is considered earlier according to the USZ-Alg.

The Aim of this study was to analyse the impact of two different coagulation algorithms on the administration of allogeneic blood products, coagulation factors, the frequency of point of care measurements and haemoglobin level during resuscitation in trauma patients.

Methods

This retrospective, multicentre, observational study included all adult trauma patients with an injury severity score (ISS) ≥ 16 primarily admitted to the USZ or the LUKS in the period of 2012 to 2014. Referred patients and patients with missing/incomplete records of the initial treatment at the emergency department (ED) were excluded. Two propensity score matched groups were created using a non-parsimonious logistic regression to account for potential differences in patient and trauma epidemiology.

Results

A total of 632 patients meeting the inclusion criteria were admitted to the two hospitals: 428 to the USZ and 204 to the LUKS. Two Propensity score matched groups (n = 172 per group) were created. Treatment with USZ-Alg compared with LUKS-Alg resulted in a lower number of patients receiving RBC transfusion (11.6% vs. 29.7%, OR 3.2, 95% CI 1.8–5.7, p < 0.001) and lower amount of RBC transfusion (0.5 SD 1.9 vs. 1.5 SD 3.9, p < 0.001). The different treatment algorithms resulted in lower mean haemoglobin levels in the USZ during resuscitation (8.0 SD 1.7 vs. 9.4 SD 1.8 g/dl, p < 0.001) and at admission to the ICU (8.3 SD 1.2 vs. 10.6 SD 1.9 g/dl, p < 0.001. Blood gas analyses to monitor treatment and haematocrit were made more frequently in the USZ (1.4 SD 0.8 vs. 1.0 SD 0.7 measurements per hour, p = 0.004).

Conclusion

A goal-directed coagulation algorithm including a target haematocrit-range including frequent and repeated haematocrit measurement may lead to less transfusion of RBC compared to only a lower haematocrit limit, when treating severely traumatized patients.

Electronic supplementary material

The online version of this article (10.1186/s13049-017-0463-0) contains supplementary material, which is available to authorized users.

Change of transfusion and treatment paradigm in major trauma patients

Trauma promotes trauma-induced coagulopathy, which requires urgent treatment with fixed-ratio transfusions of red blood cells, fresh frozen plasma and platelet concentrates, or goal-directed administration of coagulation factors based on viscoelastic testing. This retrospective observational study compared two time periods before (2005-2007) and after (2012-2014) the implementation of changes in trauma management protocols which included: use of goal-directed coagulation management; admission of patients to designated trauma centres; whole-body computed tomography scanning on admission; damage control surgery; permissive hypotension; restrictive fluid resuscitation; and administration of tranexamic acid. The incidence of massive transfusion (≥ 10 units of red blood cells from emergency department arrival until intensive care unit admission) was compared with the predicted incidence according to the trauma associated severe haemorrhage score. All adult (≥ 16 years) trauma patients primarily admitted to the University Hospital Zürich with an injury severity score ≥ 16 were included. In 2005-2007, the observed and trauma associated severe haemorrhage score that predicted the incidence of massive transfusion were identical, whereas in 2012-2014 the observed incidence was less than half that predicted (3.7% vs. 7.5%). Compared to 2005-2007, the proportion of patients transfused with red blood cells and fresh frozen plasma was significantly lower in 2012-2014 in both the emergency department (43% vs. 17%; 31% vs. 6%, respectively), and after 24 h (53% vs. 27%; 37% vs. 16%, respectively). The use of tranexamic acid and coagulation factor XIII also increased significantly in the 2012-2014 time period. Implementation of a revised trauma management strategy, which included goal-directed coagulation management, was associated with a reduced incidence of massive transfusion and a reduction in the transfusion of red blood cells and fresh frozen plasma.

Resuscitation with polymeric plasma substitutes is permissive for systemic inflammatory response syndrome and sepsis in multiply injured patients: a retrospective cohort study

OBJECTIVE

Multiple trauma is often accompanied by systemic inflammatory response syndrome (SIRS). The aim of this study was to investigate the impact of polymeric plasma substitutes on the development of SIRS or sepsis.

METHODS

We included 2969 patients aged ≥16 years with an Injury Severity Score (ISS) >16 in this study. The sample was subdivided into three groups: patients who did not receive colloids and those who received <5L colloids and >5L colloids within the first 48 h. Data were analyzed using IBM SPSS® for Windows version 22.0; analysis of variance was used for continuous normally distributed data and Kruskal-Wallis test for categorical data. The predictive quality of colloid treatment was analyzed using the receiver operating characteristic (ROC) curves. Independent predictively was analyzed by binary logistic regression. Data were considered significant if P < 0.05. Data are presented as the mean ± standard deviation.

RESULTS

The SIRS score increased with the amount of colloid used (1.9 ± 1.4 vs. 2.4 ± 1.2 vs. 3.2 ± 0.9; P < 0.001). However, the predictive quality was low, with an area under the ROC of 0.693 for SIRS and 0.669 for sepsis (P < 0.001). Binary logistic regression revealed colloids as an independent factor for the development of SIRS and sepsis (odds ratios: SIRS 3.325 and sepsis 8.984; P < 0.001).

CONCLUSION

Besides other factors, colloids have a significant permissive effect and are independent predictors for the development of SIRS and sepsis in multiply injured patients. Trial registration 'Retrospektive Analysen in der Chirurgischen Intensivmedizin' No. St. V. 01-2008.

Fresh frozen plasma is permissive for systemic inflammatory response syndrome, infection, and sepsis in multiple-injured patients

BACKGROUND

The correction of coagulopathy with fresh frozen plasma (FFP) is one of the main issues in the treatment of multiple-injured patients. Infectious and septic complications contribute to an adverse outcome in multiple-injured patients. Here, we investigated the role of FFP in the development of inflammatory complications given within the first 48 hours.

METHODS

A total of 2033 patients with multiple injuries and an Injury Severity Score greater than 16 points and aged 16 years or older were included. The population was subdivided into 2 groups: those who received FFP and those who did not. The data were analyzed using SPSS version 22.0. Associations between the data were tested using Pearson correlation. Independent predictivity was analyzed by binary logistic regression and multivariate regression. Data were considered as significant if P<.05.

RESULTS

The prothrombin time at admission was significantly lower (68.5%±23.3% vs 81.8%±21.0% normal; P<.001) in the group receiving FFP. The application of FFP led to a more severe systemic inflammatory response syndrome (SIRS) grade (3.0±1.2 vs 2.2±1.4; P<.001), to a higher infection rate (48% vs 28%; P<.001), and to a higher sepsis rate (29% vs 13%; P<.001) in the patients receiving FFP. The correlations between SIRS and the incidence of infections and sepsis increased with the amount of FFP applied (P<.001).

CONCLUSIONS

Treatment with FFP of bleeding patients with multiple injuries enhances the risk of SIRS, infection, and sepsis; however, a multifactorial genesis has to be postulated.

Fibrinogen levels in trauma patients during the first seven days after fibrinogen concentrate therapy: a retrospective study

Background

Fibrinogen concentrate (FC) is increasingly used as first line therapy in bleeding trauma patients. It remains unproven whether FC application increases post-traumatic plasma fibrinogen concentration (FIB) in injured patients, possibly constituting a prothrombotic risk. Thus, we investigated the evolution of FIB following trauma in patients with or without FC therapy.

Methods

At the AUVA Trauma Centre, Salzburg, we performed a retrospective study of patients admitted to the emergency room and whose FIB levels were documented thereafter up to day 7 post-trauma. Patients were categorized into those with (treatment group) or without (control group) FC therapy during the first 24 h after hospital admission. A subgroup analysis was carried out to investigate the influence of the amount of FC given.

Results

The study enrolled 435 patients: treatment group, n = 242 (56 %); control group, n = 193 (44 %), with median Injury Severity Score of 34 vs. 22 (P < 0.001) and massive transfusion rate of 18.4 % vs. 0.2 % (P < 0.001). In the treatment group (median FC dose 6 g), FIB was lower on admission and up to day 2 compared with the control group. In patients receiving high (≥10 g) doses of FC, FIB was lower up to day 5 as compared to controls. At other timepoints, FIB did not differ significantly between the groups. In the treatment vs. the control group, other coagulation parameters such as prothrombin time index and platelet count were consistently lower, while activated partial thromboplastin time was consistently prolonged at most timepoints. Inflammatory parameters such as C-reactive protein, interleukin-6 and procalcitonin were generally lower in controls.

Discussion

The rise of FIB levels from day 2 onwards in our study can be attributed to an upregulated fibrinogen synthesis in the liver, occurring in both study groups as part of the acute phase response after tissue injury.

Conclusions

The treatment of severe trauma patients with FC during bleeding management in the first 24 h after hospital admission does not lead to higher FIB levels post-trauma beyond that occurring naturally due to the acute phase response.

Interventional Algorithms for the Control of Coagulopathic Bleeding in Surgical, Trauma, and Postpartum Settings: Recommendations From the Share Network Group

Several clinical settings are associated with specific coagulopathies that predispose to uncontrolled bleeding. With the growing concern about the need for optimizing transfusion practices and improving treatment of the bleeding patient, a group of 9 Portuguese specialists (Share Network Group) was created to discuss and develop algorithms for the clinical evaluation and control of coagulopathic bleeding in the following perioperative clinical settings: surgery, trauma, and postpartum hemorrhage. The 3 algorithms developed by the group were presented at the VIII National Congress of the Associação Portuguesa de Imuno-hemoterapia in October 2013. They aim to provide a structured approach for clinicians to rapidly diagnose the status of coagulopathy in order to achieve an earlier and more effective bleeding control, reduce transfusion requirements, and improve patient outcomes. The group highlights the importance of communication between different specialties involved in the care of bleeding patients in order to achieve better results.

Ketamine for prehospital trauma analgesia in a low-resource rural trauma system: a retrospective comparative study of ketamine and opioid analgesia in a ten-year cohort in Iraq

Background

Opioid analgesics are used in most trauma systems, and only a few studies report on the use of ketamine for prehospital analgesia. In a low-cost rural trauma system in Iraq paramedics have been using prehospital ketamine analgesia for ten years. This study aims to evaluate the effects of prehospital analgesia on physiologic trauma severity indicators and compare the effect of ketamine and pentazocine on those indicators.

Methods

The investigation was conducted as a retrospective cohort study with parallel group design. Three subsamples of trauma patients were compared: no analgesia (n = 275), pentazocine analgesia (n = 888), and ketamine analgesia (n = 713). Physiologic severity scores were calculated based on rated values for respiratory rate, blood pressure, and consciousness. The associations between outcomes and explanatory variables were assessed using a generalized linear model.

Results

Paramedic administration of analgesia was associated with a better physiologic severity score (PSS) outcome (p = 0.01). In the two subsamples receiving analgesia significantly better outcomes were observed for respiration (p < 0.0001) and systolic blood pressure (p < 0.0001). In patients with Injury Severity Score >8 ketamine was associated with a significantly better effect on the systolic blood pressure compared to opioid analgesia (p = 0.03).

Conclusion

Prehospital analgesia for trauma victims improves physiologic severity indicators in a low-resource trauma system. Compared to pentazocine, ketamine was associated with improved blood pressure for patients with serious injuries. In a low-resource setting, ketamine seems to be a good choice for prehospital analgesia in trauma patients.

Can the Viscoelastic Parameter α-Angle Distinguish Fibrinogen from Platelet Deficiency and Guide Fibrinogen Supplementation?

Viscoelastic tests such as thrombelastography (TEG, Haemoscope Inc., Niles, IL) and thromboelastometry (ROTEM, Tem International GmbH, Munich, Germany), performed in whole blood, are increasingly used at the point-of-care to characterize coagulopathic states and guide hemostatic therapy. An algorithm, based on a mono-analysis (kaolin-activated assay) approach, was proposed in the TEG patent (issued in 2004) where the α-angle and the maximum amplitude parameters are used to guide fibrinogen supplementation and platelet administration, respectively. Although multiple assays for both the TEG and ROTEM devices are now available, algorithms based on TEG mono-analysis are still used in many institutions. In light of more recent findings, we discuss here the limitations and inaccuracies of the mono-analysis approach. Research shows that both α-angle and maximum amplitude parameters reflect the combined contribution of fibrinogen and platelets to clot strength. Therefore, although TEG mono-analysis is useful for identifying a coagulopathic state, it cannot be used to discriminate between fibrin/fibrinogen and/or platelet deficits, respectively. Conversely, the use of viscoelastic methods where 2 assays can be run simultaneously, one with platelet inhibitors and one without, can effectively allow for the identification of specific coagulopathic states, such as insufficient fibrin formation or an insufficient contribution of platelets to clot strength. Such information is critical for making the appropriate choice of hemostatic therapy.

Acute gastrointestinal bleeding - a new approach to clinical and endoscopic management

Overt or occult gastrointestinal bleeding is a frequently observed condition in routine gastroenterological practice. Occult gastrointestinal bleeding is usually a purely incidental finding, based on the discovery of iron deficiency anemia in the laboratory or blood in stool (a positive Hemoccult test). However, overt bleeding accompanied by the clinical features of tarry stool, hematemesis, or hematochezia may be a life-threatening condition, calling for immediate emergency management. In contrast to traumatology, algorithms of emergency and intensive medicine are not sufficiently validated yet for acute life-threatening bleeding. The purpose of this review was to present all established and new endoscopic hemostasis techniques and to evaluate their efficacy, as well as to provide the treating endoscopist with practical advice on how he/she could incorporate these procedures into acute medical management. The recommendations are based on inspection of the study results in the recent published literature, as well as emergency medicine algorithms in traumatology.

Changes in coagulation in standard laboratory tests and ROTEM in trauma patients between on-scene and arrival in the emergency department

BACKGROUND

When trauma patients arrive in the emergency department (ED), coagulopathy frequently is present. The time course, however, in which this coagulopathy develops is poorly understood. No study has fully evaluated the coagulation status, including thromboelastometry on-scene and at hospital arrival. We hypothesized that measured coagulation variables might change when measured at the scene of injury and upon arrival to the ED.

METHODS

We performed a prospective, single-center, observational study investigating coagulation status in 50 trauma patients on-scene and at arrival in the ED. Measurements included arterial blood gases, ROTEM®, protein S100, protein C activity, protein S, Quick value, international normalized ratio, activated partial thromboplastin time, D-dimer, coagulation factor V (FV), coagulation factor XIII (FXIII), fibrinogen, hemoglobin, hematocrit, platelets, and volume and blood products being administered during the first 24 hours.

RESULTS

Significant changes between on-scene and the ED were observed for the following values: partial venous oxygen pressure increased and sodium, glucose, and lactate decreased. For EXTEM, INTEM, and APTEM, clotting time and clot formation time increased significantly, whereas maximal clot firmness and angle α decreased significantly (all P ≤ 0.004). For FIBTEM, clotting time increased significantly and maximal clot firmness decreased significantly. In the laboratory, significant reductions in hemoglobin, hematocrit, platelets, activated partial thromboplastin time, fibrinogen, FV, FXIII, protein C activity, protein S, and protein S100 were observed (all P ≤ 0.001).

CONCLUSIONS

Although most all laboratory and rotational thromboelastometry coagulation tests worsened over time when measured on-scene and in the ED, monitoring coagulation at the scene of trauma does not provide clinically important information in a majority of trauma patients. One hour after injury, significant activation and consumption of fibrinogen, FV, FXIII, protein C activity, and protein S were observed.

Point of care and factor concentrate-based coagulation algorithms

In the last years it has become evident that the use of blood products should be reduced whenever possible. There is increasing evidence regarding serious adverse events, including higher mortality and morbidity, related to transfusions. The use of point of care (POC) devices integrated in algorithms is one of the important mechanisms to limit blood product exposure. Any type of algorithm, especially the POC-based ones, allows goal-directed transfusions of blood products and even better targeted factor concentrate substitutions. Different types of algorithms in different surgical settings (cardiac surgery, trauma, liver surgery etc.) have been established with growing interest in their use as they offer objective therapy for management and reduction of blood product use. The use of POC devices with evidence-based algorithms is important in the bleeding patient independent of its origin (traumatic vs. surgical). The use of factor concentrates compared to the classical blood products can be cost-saving, beneficial for the patient, and in agreement with the WHO-requested standard of care. The empiric and uncontrolled use of blood products such as fresh frozen plasma, red blood cells, and platelets without POC monitoring should no longer be followed with regard to actual evidence in literature. Furthermore, the use of factor concentrates may provide better outcomes and potential for cost saving.

Does resuscitation with plasma increase the risk of venous thromboembolism?

BACKGROUND

Resuscitation with blood products improves survival in patients with traumatic hemorrhage. However, the risk of venous thromboembolic (VTE) complications associated with fresh frozen plasma (FFP) resuscitation is unknown. We hypothesized that a higher ratio of FFP to packed red blood cells (PRBCs) given during acute resuscitation increases the risk of VTE independent of severity of injury and shock.

METHODS

The records of patients admitted from April 2007 to December 2011 who had surveillance lower extremity duplex ultrasounds were retrospectively reviewed. Patients who received at least 1 U of PRBCs within 24 hours of admission were included. Patients who died without VTE were excluded. The relationship between FFP and VTE was evaluated using logistic regression.

RESULTS

A total of 381 patients met inclusion criteria, of whom 77 (20.2%) developed VTE. In patients who required less than 4 U of PRBCs, increasing units of FFP were associated with an increasing risk for VTE, with each unit of FFP having an adjusted odds ratio of 1.27 (95% confidence interval, 1.04-1.54, p = 0.015). Conversely, in patients who required four or greater units of PRBCs, FFP in equal or greater ratios than PRBCs was not associated with VTE.

CONCLUSION

Each unit of FFP increased VTE risk by 25% in patients who required less than 4 U of PRBCs. In patients who required 4 U or greater PRBCs, FFP administration conferred no increased risk of VTE. This suggests that FFP should be used cautiously when early hemodynamic stability can be achieved with less than 4 U of PRBCs.

LEVEL OF EVIDENCE

Care management study, level III.

Pre-operative anaemia

Pre-operative anaemia is a relatively common finding, affecting a third of patients undergoing elective surgery. Traditionally associated with chronic disease, management has historically focused on the use of blood transfusion as a solution for anaemia in the peri-operative period. Data from large series now suggest that anaemia is an independent risk associated with poor outcome in both cardiac and non-cardiac surgery. Furthermore, blood transfusion does not appear to ameliorate this risk, and in fact may increase the risk of postoperative complications and hospital length of stay. Consequently, there is a need to identify, diagnose and manage pre-operative anaemia to reduce surgical risk. Discoveries in the pathways of iron metabolism have found that chronic disease can cause a state of functional iron deficiency leading to anaemia. The key iron regulatory protein hepcidin, activated in response to inflammation, inhibits absorption of iron from the gastrointestinal tract and further reduces bioavailability of iron stores for red cell production. Consequently, although iron stores (predominantly ferritin) may be normal, the transport of iron either from the gastrointestinal tract or iron stores to the bone marrow is inhibited, leading to a state of 'functional' iron deficiency and subsequent anaemia. Since absorption from the gastrointestinal tract is blocked, increasing oral iron intake is ineffective, and studies are now looking at the role of intravenous iron to treat anaemia in the surgical setting. In this article, we review the incidence and impact of anaemia on the pre-operative patient. We explain how anaemia may be caused by functional iron deficiency, and how iron deficiency anaemia may be diagnosed and treated.

Red blood cell storage duration and trauma

Numerous retrospective clinical studies suggest that transfusion of longer stored red blood cells (RBCs) is associated with an independent risk of poorer outcomes for certain groups of patients, including trauma, intensive care, and cardiac surgery patients. Large multicenter randomized controlled trials are currently underway to address the concern about RBC storage duration. However, none of these randomized controlled trials focus specifically on trauma patients with hemorrhage. Major trauma, particularly due to road accidents, is the leading cause of critical injury in the younger-than-40-year-old age group. Severe bleeding associated with major trauma induces hemodynamic dysregulation that increases the risk of hypoxia, coagulopathy, and potentially multiorgan failure, which can be fatal. In major trauma, a multitude of stress-associated changes occur to the patient's RBCs, including morphological changes that increase cell rigidity and thereby alter blood flow hemodynamics, particularly in the microvascular vessels, and reduce RBC survival. Initial inflammatory responses induce deleterious cellular interactions, including endothelial activation, RBC adhesion, and erythrophagocytosis that are quickly followed by profound immunosuppressive responses. Stored RBCs exhibit similar biophysical characteristics to those of trauma-stressed RBCs. Whether transfusion of RBCs that exhibit storage lesion changes exacerbates the hemodynamic perturbations already active in the trauma patient is not known. This article reviews findings from several recent nonrandomized studies examining RBC storage duration and clinical outcomes in trauma patients. The rationale for further research on RBC storage duration in the trauma setting is provided.

Viscoelastic guidance of resuscitation

PURPOSE OF REVIEW

Bleeding in trauma carries a high mortality and is increased in case of coagulopathy. Our understanding of hemostasis and coagulopathy has improved, leading to a change in the protocols for hemostatic monitoring. This review describes the current state of evidence supporting the use of viscoelastic hemostatic assays to guide trauma resuscitation.

RECENT FINDINGS

Viscoelastic hemostatic assays such as thrombelastography and rotational thrombelastometry have shown to reduce bleeding, transfusion of fresh frozen plasma and platelets, and possibly mortality in different surgical populations. In trauma care, viscoelastic hemostatic assays allows for rapid and timely identification of coagulopathy and individualized, goal-directed transfusion therapy. As part of the resuscitation concept, viscoelastic hemostatic assays seem to improve outcome also in trauma; however, there is a need for randomized clinical trials to confirm this.

SUMMARY

We are moving toward avoiding coagulopathy by individualized, goal-directed transfusion therapy, using viscoelastic hemostatic assays to guide ongoing resuscitation of actively bleeding patients in a goal-directed manner.

In vitro combinations of red blood cell, plasma and platelet components evaluated by thromboelastography

BACKGROUND

Thromboelastography is increasingly used to evaluate coagulation in massively bleeding patients. The aim of this study was to investigate how different combinations of blood components affect in vitro whole blood clotting measured by thromboelastography.

MATERIALS AND METHODS

Packed red blood cells, plasma and platelets from fresh and old blood components were mixed in vitro, in proportions of 4:4:1, 5:5:2, 8:4:1 and 2:1:0, and analysed with thromboelastography. For the ratio 4:4:1 the experiment was done at both 37 °C and 32 °C.

RESULTS

Thromboelastography curves were within normal reference values for the blood component proportions of 4:4:1 and 5:5:2. For 8:4:1, the angle and maximal amplitude were reduced below normal values, indicating low levels of fibrinogen and/or platelets. For the 2:1:0 proportion, all parameters were affected resulting in severely impaired in vitro clot formation. The reaction-time, reflecting the coagulation factor-dependent, initial clot formation, was slightly increased at a low temperature. Prolonged storage of the components did not affect the curve.

DISCUSSION

With the introduction of guidelines on the management of massive bleeding it is important to have tools for the assessment of the new protocols. In vitro evaluation of mixtures of packed red blood cells, plasma and platelets by thromboelastography may be relevant in the prediction of in vivo clot formation and haemostasis.

Perioperative coagulopathy monitoring

Coagulopathy is common in orthopedic surgery patients either due to acquired factors, such as surgery, trauma, medications, or hemorrhage. Perioperative monitoring of blood coagulation is critical to diagnose the causes of hemorrhage, guide hemostatic therapies, predict the risk of bleeding during surgical procedures, and reduce risk of postoperative cardiac and thromboembolic events. In contrast to previous interventions that measure specific portions of the clotting cascade (such as intrinsic or extrinsic pathways or platelet aggregation), "Point-of-care" coagulation monitoring devices assess the viscoelastic properties of whole blood. These techniques have the potential to measure the entire clotting process, starting with fibrin formation, clot retraction, and fibrinolysis. Furthermore, the coagulation status of patients is assessed in whole blood, allowing the plasmatic coagulation system to interact with platelets and red cells, and thereby providing useful additional information on platelet function. Improved monitoring of coagulopathy is particularly important as new anticoagulant drugs emerge that affect the clotting cascade in novel ways, including the inhibition of intrinsic and extrinsic pathways and platelet function. It is important for orthopedic surgeons to understand the pharmacology and reversal of these drugs in the perioperative setting. The purpose of this review is to review the current techniques to monitoring perioperative coagulopathy and to identify the manner in which novel anticoagulant medications affect the clotting cascade with particular interest in trauma and spine surgery.

[Upper gastrointestinal bleeding and haemorrhagic shock at the end of the holidays: pre-hospital and in-hospital management of a gastrointestinal emergency]

Upon returning from holidays, a 55-year-old patient presenting with melena and haemorrhagic shock was admitted to a University hospital after receiving first emergency medical care in a German InterCity train. In an interdisciplinary effort, haemodynamics were stabilised and the airway and respiratory function were secured. Under emergency care conditions the patient then underwent an emergency upper GI endoscopy where a spurting arterial upper gastrointestinal bleeding (Forrest 1a) was found. While the bleeding could not be controlled with endoscopic techniques, definitive haemostasis was achieved with a surgical laparotomy. While not commonly established for patients with severe GI bleeding, by spontaneous implementation of an interdisciplinary trauma room approach following established trauma algorithms the team was able to achieve stabilisation of vital functions and final control of bleeding in this highly unstable patient. Although the majority of upper gastrointestinal bleedings spontaneously cease, emergency care algorithms should be developed and implemented for patients with severe gastrointestinal bleedings in shock. Following the case vignette, we discuss a potential approach and develop an exemplary protocol for shock room management in this patient subgroup.

Management of hemorrhage in trauma

Hemorrhage remains one of the leading causes of trauma-related deaths. Uncontrolled diffuse microvascular bleeding in the course of initial care is common, potentially resulting in exsanguination. Early and aggressive hemostatic intervention increases survival and reduces the incidence of massive transfusion. Thus, timely diagnosis of the underlying coagulation disorders is mandatory. It has been shown that standard coagulation tests do not sufficiently characterize trauma-induced coagulopathy (TIC). This has led to increasing interest in alternatives, such as the viscoelastic test, to diagnose TIC and to provide the basis for a goal-directed hemostatic therapy. The concept of damage control resuscitation (DCR) has been introduced widely in trauma patients with severe bleeding. This strategy addresses important confounders of the coagulation process such as hemodilution, hypothermia, and acidosis; DCR is based on a damage control surgical approach, permissive hypotension, and improvement of hemostatic competence. Many studies have shown benefit in mortality when using high ratios of fresh frozen plasma (FFP) to red blood cells (RBC) as early treatment. However, there is increased awareness that coagulation factor concentrate could be beneficial in the treatment of trauma-induced coagulopathy.

Logistics of transfusion support for patients with massive hemorrhage

PURPOSE OF REVIEW

Traditionally, trauma resuscitation protocols have advocated sequential administration of therapeutic components, beginning with crystalloid solutions infused to replace lost intravascular volume. However, rapid restoration of the components of blood is essential for ensuring adequate tissue perfusion and for preventing acidosis, coagulopathy, and hypothermia, referred to as the 'lethal triad' in trauma settings. The review summarizes practical approaches for transfusion support of patients with massive hemorrhage.

RECENT FINDINGS

Massive transfusion protocols for blood transfusion support are reviewed, including practical considerations from our own. We maintain an inventory of thawed, previously frozen plasma (four units each of blood group O and A), which can be issued immediately for patients in whom the blood type is known. As frozen plasma requires 45 min to thaw, liquid AB plasma (26 day outdate) functions as an excellent alternative, particularly for patients with unknown or blood group B or AB types.

SUMMARY

Close monitoring of bleeding and coagulation in trauma patients allows goal-directed transfusions to optimize patients' coagulation, reduce exposure to blood products, and to improve patient outcomes. Future studies are needed to understand and demonstrate improved patient outcomes.

Update on prehospital emergency care of severe trauma patients

The prognosis of severe trauma patients is determined by the ability of a healthcare system to provide high intensity therapeutic treatment on the field and to transport patients as quickly as possible to the structure best suited to their condition. Direct admission to a specialized center ("trauma center") reduces the mortality of the most severe trauma at 30 days and one year. Triage in a non-specialized hospital is a major risk of loss of chance and should be avoided whenever possible. Medical dispatching plays a major role in determining patient care. The establishment of a hospital care network is an important issue that is not formalized enough in France. The initial triage of severe trauma patients must be improved to avoid taking patients to hospitals that are not equipped to take care of them. For this purpose, the MGAP score can predict severity and help decide where to transport the patient. However, it does not help predict the need for urgent resuscitation procedures. Hemodynamic management is central to the care of hemorrhagic shock and severe head trauma. Transport helicopter with a physician on board has an important role to allow direct admission to a specialized center in geographical areas that are difficult to access.

Haemorrhagic shock, therapeutic management

The management of a patient in post-traumatic haemorrhagic shock will meet different logics that will apply from the prehospital setting. This implies that the patient has beneficiated from a "Play and Run" prehospital strategy and was sent to a centre adapted to his clinical condition capable of treating all haemorrhagic lesions. The therapeutic goals will be to control the bleeding by early use of tourniquet, pelvic girdle, haemostatic dressing, and after admission to the hospital, the implementation of surgical and/or radiological techniques, but also to address all the factors that will exacerbate bleeding. These factors include hypothermia, acidosis and coagulopathy. The treatment of these contributing factors will be associated to concepts of low-volume resuscitation and permissive hypotension into a strategy called "Damage Control Resuscitation". Thus, the objective in situation of haemorrhagic shock will be to not exceed a systolic blood pressure of 90 mmHg (in the absence of severe head trauma) until haemostasis is achieved.

A brief review of 50 years of perioperative thrombosis and hemostasis management

Perioperative thrombosis and hemostasis management has changed dramatically over the past 50 years. From two anticoagulants and one anti-aggregant, the number of currently available drugs has recently increased several-fold, leaving clinicians with the problem of choosing the optimal agent. Individualized preoperative assessment of bleeding risk based on bleeding history and testing limited to high-risk patients is an emerging concept. Based on the identification of risk factors for venous thromboembolism (VTE), pharmacologic and non-pharmacologic strategies for perioperative VTE prophylaxis have had a major impact on patient outcome. For patients undergoing surgery who are treated with anticoagulants and anti-aggregants, "bridging" strategies have been proposed. Bleeding management strategies have shifted focus from replacing lost blood volume to new approaches aimed at preventing blood loss, reducing the potential complications of blood loss, and preventing the transfusion of blood products. For some areas of perioperative thrombosis and hemostasis management, randomized controlled trial (RCT) data are emerging, but the database remains insufficient to date. Clearly, more RCTs need to be published for perioperative thrombosis and hemostasis management to become an evidence-based approach.