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30/04/2019

Sang total: Une vision US

Whole Blood in Trauma: A Review for Emergency Clinicians.

 
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Comme quoi une roue est faite pour tourner. La même démarche chez les norvégiens en prégospitalier (1)

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BACKGROUND:

Blood products are a cornerstone of trauma resuscitation. From the historically distant battlefields of World War II through present-day conflict around the globe, whole blood (WB) has been a potent tool in the treatment of massive hemorrhagic shock. Component therapy with a targeted ratio of packed red blood cells, platelets, and plasma has previously been utilized.

OBJECTIVES:

This narrative review describes modern-day WB transfusion, its benefits, potential drawbacks, and implementation.

DISCUSSION:

The current form of stored low-titer O WB seems to be the safest and most effective solution. There are many advantages to WB, including the maintenance of coagulation factors, the lack of subsequent thrombocytopenia, and the reduction of infused anticoagulant. Several studies suggest its utility in trauma.

WholeBlood strategy.jpg

Most of the disadvantages of WB stem from a lack of prospective data on the topic, which are likely forthcoming. Logistical issues likely present the greatest barrier to this therapy, but an advanced prehospital protocol developed in San Antonio, Texas, has successfully overcome several of these challenges.

CONCLUSIONS:

Although stored WB holds promise, it is not without its distinct challenges, including logistical issues, which this article addresses. There are programs underway currently that demonstrate its feasibility in metropolitan areas. As demonstrated in military settings, WB is likely the ideal resuscitation fluid for civilian trauma in the prehospital and emergency department settings.

26/04/2019

Fibrinogène lyophilisé: Stable 6 mois jusquà 50°c

 

Stability of Fibrinogen Concentrate in Human Blood Samples: An In Vitro Study

Martini WZ1 et Al Mil Med. 2018 Mar 1;183(suppl_1):183-188. doi: 10.1093/milmed/usx176.
 
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Le fibrinogène est le premier facteur de coagulation à décroitre lors de l'installation d'une coagulopathie traumatique. Selon  les dernières recommandations SFAR, l’administration de concentrés de fibrinogène est probablement recommandée en cas de fibrinogénémie ≤1,5g/L, ou de paramètres thromboélasto-graphiques(-métriques) de déficit en fibrinogène fonctionnel. Unedose initiale de 3g est suggérée chez un adultede 70 Kg.  Cet apport est réalisé, non tant par l'apport de plasma ( au moins 4à 6 unités sont nécessaires) que par des concentrés de fibrinogène (En France Clottafact 1,5g/flacon). Le travail proposé est très intéressant car il met en avant l'avantage de formes lyophylisées ( RiaStap). Il existe une autre forme produite aux USA: le  Fibryga d'introduction très récente. Tout ceci milite pour l'introduction du fibrinogène lyophylisé dans la pratique du remote damage control resuscitation, tel que proposé par ces équipes (1, 2)
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OBJECTIVES: 

 

This study was designed to assess the stability and functional activity of fibrinogen concentrates subjected to the changes in temperature and duration observed in field conditions.

 

METHODS: 

 

Fibrinogen concentrate was stored at -20°C (12 vials), 22°C (12 vials), and 50°C with 80% humidity (12 vials), for up to 6 mo. At each temperature, three vials of fibrinogen concentrate were taken out at 0, 1, 3, and 6 mo and reconstituted. On analysis days, blood samples were taken from a single healthy donor to collect plasma samples. The donor plasma was mixed with commercial fibrinogen-deficient plasma to make fibrinogen-adjusted plasma (FAP). An aliquot of the reconstituted fibrinogen concentrate was used for quantification of stored fibrinogen content (using STA-R) and function (Rotem - Fibtem) in FAP.

 

RESULTS: 

At 22°C for 0, 1, 3, and 6 mo, there were no significant changes observed in fibrinogen content (1,223 ± 42 mg/vial, 1,286 ± 86 mg/vial, 1,234 ± 76 mg/vial, and 1,178 ± 64 mg/vial), prothrombin time (13.5 ± 0.1 s, 13.7 ± 0.6 s, 13.3 ± 0.4 s, and 13.7 ± 0.2 s), or activated partial thromboplastin time (31.1 ± 0.2 s, 32.0 ± 0.2 s, 31.5 ± 0.2 s, and 32.0 ± 0.8 s), respectively.

Fib lyoph.jpg

There were also no significant changes observed in any of the Fibtem measurements. Similarly, no differences were observed in these variables over time at -20°C and 50°C with 80% humidity.

 

CONCLUSIONS: 

 

Fibrinogen concentrate maintained its content and function when stored at -20°C to 50°C with up to 80% humidity for 6 mo.

24/04/2019

Numéro special THOR

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01/04/2019

Oxsealife: LE cristalloïde de demain ?

The effect of a novel intravenous fluid (Oxsealife®) on recovery from haemorrhagic shock in pigs.
 

 

Blood transfusion is given according to haemoglobin thresholds aimed at restoration of arterial oxygen-carrying capacity. Patient survival after severe haemorrhagic shock depends on restoration of microvascular perfusion, tissue oxygen delivery, endothelial function and organ integrity. We investigated a novel crystalloid fluid designed for tissue oxygen delivery, Oxsealife® , with components that generate microvascular nitric oxide and scavenge reactive oxygen species generated during ischaemia-reperfusion injury. The amount of dissolved oxygen in blood progressively increased during step-wise in vitro haemodilution with this fluid, suggesting that the oxygen solubility coefficient of blood is dynamic, not static. We performed a pilot safety and efficacy study to compare resuscitation with this novel crystalloid vs. whole blood transfusion in a swine haemorrhagic shock model with animals bled to an arterial lactate oxygen debt target. Despite contributing no haemoglobin, viscosity nor oncotic potential, resuscitation with Oxsealife after severe haemorrhagic shock restored central haemodynamic parameters comparable to stored allogeneic blood transfusion. Tissue perfusion, oxygenation and metabolic outcomes were equivalent between treatment groups. Increased consumption of bicarbonate in animals given Oxsealife suggested greater capillary recruitment and enhanced clearance of acidic tissue metabolites. Serum markers of organ function, animal activity during recovery and histological analysis of tissue morphology and endothelial glycocalyx integrity confirmed functional recovery from haemorrhagic shock. We conclude that recovery of tissue oxygen delivery and organ function after haemorrhagic shock may not be dependent on treatments that increase haemoglobin levels. Oxsealife shows promise for treatment of severe haemorrhagic shock and may reduce the requirement for allogeneic blood products.

11/03/2019

Sang total de banque: Oui mais avec une logistique adhoc

The use of whole blood in US military operations in Iraq, Syria, and Afghanistan since the introduction of low-titer Type O whole blood: feasibility, acceptability, challenges.

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L'emploi de sang total est redevenu d'actualité, qu'il s'agisse de sang prélevé sur pied ou conservé en banque. Ce dernier est de plus en plus employé, notamment en role 2, avec cependant une difficulté qui tient à une moindre durée de conservation (21 jours en poche CPD  et 35 jours en poche CPDA-1). Réduire le délai prélèvement-délivrance sur zone est donc fondamental si l'on souhaite en tirer le meilleur bénéfice. La production sur zone de combat de ce type de produit pourrait être une solution. 

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BACKGROUND:

 

Hemorrhage is the leading cause of preventable death in military and civilian traumatic injury. Blood product resuscitation improves survival. Low-titer Type O Whole Blood (LTOWB) was recently re-introduced to the combat theater as a universal resuscitation product for hemorrhagic shock. This study assessed the utilization patterns of LTOWB compared to warm fresh whole blood (WFWB) and blood component therapy (CT) in US Military Operations in Iraq/Syria and Afghanistan known as Operation Inherent Resolve (OIR) and Operation Freedom's Sentinel (OFS) respectively. We hypothesized LTOWB utilization would increase over time given its advantages.

STUDY DESIGN AND METHODS:

 

Using the Theater Medical Data Store, patients receiving blood products between January 2016 and December 2017 were identified. Product utilization ratios (PUR) for LTOWB, WFWB, and CT were compared across Area of Operations (AORs), medical treatment facilities (Role 2 vs. Role 3), and time. PUR was defined as number of blood products transfused/(number of blood products transfused + number of blood products wasted).

RESULTS:

The overall PUR for all blood products was 17.4%; the LTOWB PUR was 14.3%. Over the study period, the total number of blood products transfused increased 133%. Although the total whole blood (WB) increased from 2.1% to 6.6% of all products transfused, WFWB use remained at 2% while LTOWB transfusions increased from 0.5% to 4%. Transfusion of LTOWB occurred more in austere Role 2 facilities compared to Role 3 hospitals.

CONCLUSIONS:

LTOWB transfusion is feasible in austere, far-forward environments. Further investigation is needed regarding the safety, clinical outcomes, and drivers of LTOWB transfusions.

04/03/2019

Transfusion: Numéro spécial Trauma

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Clic sur l'image pour accéder aux documents

22/01/2019

Thrombosomes: C'est parti

Safety evaluation of a lyophilized platelet-derived hemostatic product.

BACKGROUND:

Hemorrhage causes significant morbidity and mortality in people aged <65 years. lyophilized platelet-derived hemostatic agent (Thrombosomes) demonstrated hemostatic efficacy in animal models. We report the results of the first safety trial of autologous Thrombosomes given to normal subjects.

STUDY DESIGN AND METHODS:

Ten subjects received autologous Thrombosomes prepared from their apheresis platelets, and five control subjects received a buffer solution. There were five cohorts, with three subjects per cohort (two in the Thrombosomes group and one in the control group). Doses escalated from 1/1,000 to 1/10 of a proposed efficacious dose. Cohorts 4 and 5 received the highest dose, but in Cohort 5, one-half the dose was infused 2 hours apart. Cohorts 1 through 3 were monitored for 42 days, Cohorts 4 and 5 were monitored for 60 days using hematology, coagulation, and chemistry assays and antibody testing.

RESULTS:

There were no serious adverse events (AEs) and no subject withdrawals. There were eight treatment-related AEs (TRAEs) in 5 of 15 subjects (33%) (four in the Thrombosomes group and one in the control group). Of four subjects receiving the highest doses, three had TRAEs. One had elevated D-dimer, prothrombin fragment 1 + 2, and white blood cell count (subject had concurrent upper respiratory tract infection); one had T-wave inversions in precordial leads V2 and V3 without elevated troponin or symptoms; and one had a platelet autoantibody without change in plateletcount. All subjects' TRAEs resolved by Day 21.

CONCLUSION:

There were no serious AEs in this small study. Thrombosomes were considered safe at the doses assessed. Future, larger trials will be needed to further assess safety and efficacy.

21/01/2019

Sang total: A nouveau disponible

L'emploi de sang total n'est pas une nouveauté. C'est même la base de la transfusion sanguine dans les pays à faible infrastructure médicale.

 

poches-de-sang-total.jpg

Nous en avions, comme le PLyo, perdu l'usage avec l'arrivée des transfusions fractionnées par composants. Le renouveau du sang total pour la prise en charge des blessés de guerre l'a remis en selle, de même que toutes les techniques de préparation permettant sa conservation tout en préservant ses qualités hémostatiques. Le sang total « froid » préparé par le CTSA est un produit universel, déleucocyté, qualifié biologiquement, à bas titre d'hémolysine. Son intérêt principal est d'apporter plaquettes fonctionnelles et facteurs de coagulation. Il reste à démontrer que les qualités potentielles de ce "nouveau" produit ne s'altèrent pas avec le temps. Il peut être a priori conservé 3 semaines (?). Il s'agit d'une nouvelle importante pour le développement de la transfusion préhospitalière.

Pas + de 10 CGR âgés de +22j pour le traumatisé grave

Older Blood Is Associated With Increased Mortality and Adverse Events in Massively TransfusedTrauma PatientsSecondary Analysis of the PROPPR Trial.
 

STUDY OBJECTIVE:

The transfusion of older packed RBCs may be harmful in critically ill patients. We seek to determine the association between packed RBC age and mortality among trauma patients requiring massive packed RBC transfusion.

METHODS:

We analyzed data from the Pragmatic, Randomized Optimal Platelet and Plasma Ratios trial. Subjects in the parent trial included critically injured adult patients admitted to 1 of 12 North American Level I trauma centers who received at least 1 unit of packed RBCs and were predicted to require massive blood transfusion. The primary exposure was volume of packed RBC units transfused during the first 24 hours of hospitalization, stratified by packed RBC age category: 0 to 7 days, 8 to 14 days, 15 to 21 days, and greater than or equal to 22 days. The primary outcome was 24-hour mortality. We evaluated the association between transfused volume of each packed RBC age category and 24-hour survival, using random-effects logistic regression, adjusting for total packed RBC volume, patient age, sex, race, mechanism of injury, Injury Severity Score, Revised TraumaScore, clinical site, and trial treatment group.

RESULTS:

The 678 patients included in the analysis received a total of 8,830 packed RBC units. One hundred patients (14.8%) died within the first 24 hours. On multivariable analysis, the number of packed RBCs greater than or equal to 22 days old was independently associated with increased 24-hour mortality (adjusted odds ratio [OR] 1.05 per packed RBC unit; 95% confidence interval [CI] 1.01 to 1.08): OR 0.97 for 0 to 7 days old (95% CI 0.88 to 1.08), OR 1.04 for 8 to 14 days old (95% CI 0.99 to 1.09), and OR 1.02 for 15 to 21 days old (95% CI 0.98 to 1.06). Results of sensitivity analyses were similar only among patients who received greater than or equal to 10 packed RBC units.

CONCLUSION:

Increasing quantities of older packed RBCs are associated with increased likelihood of 24-hour mortality in trauma patients receiving massive packed RBC transfusion (≥10 units), but not in those who receive fewer than 10 units.

16/01/2019

Plyo prehospitalier: N'améliore pas la survie ?

The impact of prehospital administration of freeze-dried plasma on casualty outcome.

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Ce travail qui porte sur l'étude de l'impact, chez des blessés en choc hémorragique,  de la perfusion préhospitalière de PLyo confirme son intérêt en terme d'économie transfusionnelle mais pas en terme de mortalité. Les auteurs mettent en avant la taille de leur cohorte de blessés pour expliquer ce résultat négatif. On notera également les délais courts de transport.
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BACKGROUND:

Hemorrhage is the most common preventable cause of death in both civilian and military trauma. There is no consensus regarding the appropriate fluid resuscitation protocol. Plasma, as a resuscitative fluid, has substantial benefits as a volume expander, owing to its relatively high oncotic pressure and its positive effect on trauma-induced coagulopathy by replenishing the lost coagulation factors, rather than diluting the casualty's remaining factors. The Israel Defense Force Medical Corps decided to use freeze-dried plasma (FDP) as the fluid of choice for casualties in hemorrhagic shock in the prehospital setting. The aim of our study is to compare the differences of coagulation, perfusion measurements, resource utilization, and outcome between casualties receiving FDP to casualties who did not receive FDP in the prehospital setting.

METHODS:

This is a retrospective matched cohort study based on two groups of casualties (those treated with FDP vs. those without FDP treatment). The control group was compiled in three steps of precision for age, sex, mechanism of injury and maximum level of severity for each nine injured body regions. Data were collected from the IDF Trauma Registry and The National Israel Trauma Registry.

RESULTS:

The study group comprised 48 casualties receiving FDP and 48 controls with no differences in demographic, evacuation time, and injury characteristics. The FDP group demonstrated a lower level of hemoglobin (12.7 gr/dzl) (odds ratio [OR], 3.11; 95% confidence interval [CI], 1.10-8.80), lower level of international normalized ratio (1.1) (OR, 3.09; 95% CI, 1.04-9.14), and lower level of platelets (230 × 109/L) (OR, 3.06; 95% CI, 1.16-8.06). No other differences were found between the two groups.

 

" In the total study population, seven (7.3%) casualties died in hospital, among which 8.3% were from the FDP group, compared with 6.2% from the control group"

CONCLUSION:

The use of FDP in the prehospital setting has logistic benefits and a positive effect on coagulation profile, with no other significant effects. Future studies need to be performed on larger groups to verify trends or nullify our hypotheses.

 

08/01/2019

TXA à l'avant: Peut être pas si simple !

Prehospital Tranexamic Acid Administration During Aeromedical Transport After Injury.

Boudreau RM et Al. J Surg Res. 2019 Jan;233:132-138
 
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Un article de plus qui doit faire interroger sur l'intérêt réel du TXA, notamment son administration quai systématique à l'avant et pointe la réalité des complications thrombo-emboliques. Une plus grande sélectivité dans les critères d'administration est discutée.
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BACKGROUND:

Tranexamic acid (TXA) has been shown to reduce mortality in the treatment of traumatic hemorrhage. This effect seems most profound when given early after injury. We hypothesized that extending a protocol for TXA administration into the prehospital aeromedical setting would improve outcomes while maintaining a similar safety profile to TXA dosed in the emergency department (ED).

MATERIALS AND METHODS:

We identified all trauma patients who received TXA during prehospital aeromedical transport or in the ED at our urban level I trauma center over an 18-mo period. These patients had been selected prospectively for TXA administration using a protocol that selected adult trauma patients with high-risk mechanism and concern for severe hemorrhage to receive TXA. Patient demographics, vital signs, lab values including thromboelastography, blood administration, mortality, and complications were reviewed retrospectively and analyzed.

RESULTS:

One hundred sixteen patients were identified (62 prehospital versus 54 ED). Prehospital TXA patients were more likely to have sustained blunt injury (76% prehospital versus 46% ED, P = 0.002). There were no differences between groups in injury severity score or initial vital signs.

TXA.jpeg

There were no differences in complication rates or mortality. Patients receiving TXA had higher rates of venous thromboembolic events (8.1% in prehospital and 18.5% in ED) than the overall trauma population (2.1%, P < 0.001).

CONCLUSIONS:

Prehospital administration of TXA during aeromedical transport did not improve survival compared with ED administration. Treatment with TXA was associated with increased risk of venous thromboembolic events. Prehospital TXA protocols should be refined to identify patients with severe hemorrhagic shock or traumatic brain injury.

 

30/12/2018

HEXACYL: Oui , mais attention à la MTE

Tranexamic acid administration is associated with an increased risk of posttraumatic venous thromboembolism.

 

BACKGROUND:

Tranexamic acid (TXA) is used as a hemostatic adjunct for hemorrhage control in the injured patient and reduces early preventable death. However, the risk of venous thromboembolism (VTE) has been incompletely explored. Previous studies investigating the effect of TXA on VTE vary in their findings. We performed a propensity matched analysis to investigate the association between TXA and VTE following trauma, hypothesizing that TXA is an independent risk factor for VTE.

METHODS:

This retrospective study queried trauma patients presenting to a single Level I trauma center from 2012 to 2016. Our primary outcome was composite pulmonary embolism or deep vein thrombosis. Mortality, transfusion, intensive care unit and hospital lengths of stay were secondary outcomes. Propensity matched mixed effects multivariate logistic regression was used to determine adjusted odds ratio (aOR) and 95% confidence intervals (95% CI) of TXA on outcomes of interest, adjusting for prespecified confounders. Competing risks regression assessed subdistribution hazard ratio of VTE after accounting for mortality.

RESULTS:

Of 21,931 patients, 189 pairs were well matched across propensity score variables (standardized differences <0.2). Median Injury Severity Score was 19 (interquartile range, 12-27) and 14 (interquartile range, 8-22) in TXA and non-TXA groups, respectively (p = 0.19). Tranexamic acid was associated with more than threefold increase in the odds of VTE (aOR, 3.3; 95% CI, 1.3-9.1; p = 0.02).

TXA.jpg

Tranexamic acid was not significantly associated with survival (aOR, 0.86; 95% CI, 0.23-3.25; p = 0.83). Risk of VTE remained elevated in the TXA cohort despite accounting for mortality (subdistribution hazard ratio, 2.42; 95% CI, 1.11-5.29; p = 0.03).

CONCLUSION:

Tranexamic acid may be an independent risk factor for VTE. Future investigation is needed to identify which patients benefit most from TXA, especially given the risks of this intervention to allow a more individualized treatment approach that maximizes benefits and mitigates potential harms.

| Tags : coagulopathie

15/12/2018

Hydroxocobalamine: Pour la coagulopathie et la pression

Intravenous Hydroxocobalamin Versus Hextend Versus Control for Class III Hemorrhage Resuscitation in a Prehospital Swine Model

Bebarta VS et Al. Mil Med. 2018 Nov 5;183(11-12):e721-e729.

 

Background: Hydroxyethyl starch (Hextend) has been used for hemorrhagic shock resuscitation, however, hydroxyethyl starch may be associated with adverse outcomes.

Objective: To compare systolic blood pressure (sBP) in animals that had 30% of their blood volume removed and treated with intravenous hydroxocobalamin, hydroxyethyl starch, or no fluid.

Methods: Twenty-eight swine (45-55 kg) were anesthetized and instrumented with continuous femoral and pulmonary artery pressure monitoring. Animals were hemorrhaged 20 mL/kg over 20 minutes and then administered 150 mg/kg IV hydroxocobalamin in 180 mL saline, 500 mL hydroxyethyl starch, or no fluid and monitored for 60 minutes. Data were modeled using repeated measures multivariate analysis of variance.

Results: There were no significant differences before treatment. At 20 minutes after hemorrhage, there was no significant difference in mean sBP between treated groups, however, control animals displayed significantly lower mean sBP (p < 0.001). Mean arterial pressure and heart rate improved in the treated groups but not in the control group (p < 0.02). Prothrombin time was longer and platelet counts were lower in the Hextend group (p < 0.05). Moreover, thromboelastography analysis showed longer clotting (K) times (p < 0.05) for the hydroxyethyl starch-treated group.

Conclusion: Hydroxocobalamin restored blood pressure more effectively than no treatment and as effectively as hydroxyethyl starch but did not adversely affect coagulation.

09/12/2018

Délivrance du sang: Merci les TAP

Air-drop blood supply in the French Army
 
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Pas trop de surprise concernant les résultats de ce test. La délivrance de sang par voie aérienne se fait régulièrement dans les pays en voie de développement, notamment par l'emploi de drônes
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BACKGROUND:

Haemorrhagic shock remains the leading cause of preventable death in overseas and austere settings. Transfusion of blood components is critical in the management of this kind of injury. For French naval and ground military units, this supply often takes too long considering the short shelf-life of red blood cell concentrates (RBCs) and the limited duration of transport in cooling containers (five to six days). Air-drop supply could be an alternative to overcome these difficulties on the condition that air-drop does not cause damage to blood units.

METHODS:

After a period of study and technical development of packaging, four air-drops at medium and high altitudes were performed with an aircraft of the French Air Force. After this, one air-drop was carried out at medium altitude with 10 RBCs and 10 French lyophilised plasma (FLYP). A second air-drop was performed with a soldier carrying one FLYP unit at 12 000 feet. For these air-drops real blood products were used, and quality control testing and temperature monitoring were performed.

RESULTS:

The temperatures inside the containers were within the normal ranges. Visual inspection indicated that transfusion packaging and dumped products did not undergo deterioration. The quality control data on RBCs and FLYP, including haemostasis, suggested no difference before and after air-drop.

DISCUSSION:

The operational implementation of the air-drop of blood products seems to be one of the solutions for the supply of blood products in military austere settings or far forward on battlefield, allowing safe and early transfusion.

08/11/2018

Transport du sang en opex: Loin d'être anodin !

Bringing Packed Red Blood Cells to the Point of Combat Injury: Are We There Yet?

Ünlü et Al.Turk J Haematol. 2018 Aug 3;35(3):185-191.

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Transfuser le plus tôt possible serait un facteur de survie chez le blessé de guerre. Encore faut il disposer de sang et donc d'en transporter. On connaît les règles imposées en métropole. Les conditions de transport en opérations 'ont rien à voir avec celles de métropole. C'est bien ce que décrit cet article qui incite à la prudence. Seules 13% de poches récentes soumises à des vibrations intenses peuvent être transfusées après 06h d'exposition à des vibrations intenses.

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OBJECTIVE:

 

Hemorrhage is the leading cause of injury-related prehospital mortality. We investigated worst-case scenarios and possible requirements of the Turkish military. As we plan to use blood resources during casualty transport, the impact of transport-related mechanical stress on packed red blood cells (PRBCs) was analyzed.

 

 

MATERIALS AND METHODS:

 

The in vitro experiment was performed in the environmental test laboratories of ASELSAN®. Operational vibrations of potential casualty transport mediums such as Sikorsky helicopters, Kirpi® armored vehicles, and the NATO vibration standard MIL-STD-810G software program were recorded. The most powerful mechanical stress, which was created by the NATO standard, was applied to 15 units of fresh (≤7 days) and 10 units of old (>7 days) PRBCs in a blood cooler box. The vibrations were simulated with a TDS v895 Medium-Force Shaker Device. On-site blood samples were analyzed at 0, 6, and 24 h for biochemical and biomechanical analyses.

 

RESULTS:

The mean (±standard deviation) age of fresh and old PRBCs was 4.9±2.2 and 32.8±11.8 days, respectively. Six-hour mechanical damage of fresh PRBCs was demonstrated by increased erythrocyte fragmentation rates (p=0.015), hemolysis rates (p=0.003), and supernatant potassium levels (p=0.003) and decreased hematocrit levels (p=0.015). Old PRBC hemolysis rates (p=0.015), supernatant potassium levels (p=0.015), and supernatant hemoglobin (p=0.015) were increased and hematocrit levels were decreased (p=0.015) within 6 h.

 

TJH-35-185-g5.jpg

 

Two (13%) units of fresh PRBCs and none of the old PRBCs were eligible for transfusion after 6 h of mechanical stress.

 

CONCLUSION:

When an austere combat environment was simulated for 24 h, fresh and old PRBC hemolysis rates were above the quality criteria. Currently, the technology to overcome this mechanical damage does not seem to exist. In light of the above data, a new national project is being performed.

 

24/10/2018

Don de sang: Capacité à l'exercice en baisse pour 2 Jours

The effect of a standard whole blood donation on oxygen uptake and exercise capacity: a systematic review and meta-analysis.

Van Remoortel H et Al. Transfusion. 2017 Feb;57(2):451-462

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Le recours à une banque de sang sur pied est très tentante dès lors que du sang conservé n'est pas ou peu disponible. Néanmoins dans nos conditions d'exercice ce prélèvement s'effectue sur des combattants dont les capacités physiques ne doivent pas être altérées. Ceci est d'autant plus vrai si ils peuvent présenter une déshydratation liée à leur exercice. La méta-analyse présentée ici met en évidence d'une part une baisse des paramètres physiologiques d'aptitude à l'effort pendant 48h et d'autre part le fait que le volume prélevé compte. Les sportifs entraînés pourraient avoir une meilleure tolérance au don de sang (1)

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BACKGROUND:

Blood is a life-saving product for many people worldwide. Voluntary blood donation serves the demand for blood but there are concerns among potential donors about the impact of blood loss on exercise performance. This systematic review aimed to collect the best available evidence of the effect of a standard whole blood donation on aerobic exercise performance.

STUDY DESIGN AND METHODS:

Studies from six databases dealing with a standard whole blood donation (400-500 mL) followed by (sub)maximal exercise were retained. The outcomes included exercise-related blood variables (hemoglobin [Hb] concentration, hematocrit, and red blood cell count) and endurance exercise variables ((sub)maximal oxygen uptake, peak work rate, and time to exhaustion). Overall effects at different time points postdonation were investigated by performing meta-analyses and calculating mean differences (and 95% confidence intervals). The GRADE methodology (Grades of Recommendation, Assessment, Development, and Evaluation) was used to assess the quality of evidence.

RESULTS:

We identified 6237 references and finally included 18 before-after studies of low quality. Twenty-four to 48 hours after a blood donation, 1) Hb concentration was reduced (7% decrease) until 14 days after the blood donation (4% decrease), 2) maximal oxygen uptake(VO2max ) was lower (7% decrease), and 3) a reduction in maximal exercise capacity (10% decrease) was present.

CONCLUSION:

The best available evidence indicates that standard whole blood donation (400-500 mL) leads to small but potentially physiologically important reductions in Hb levels, VO2max , and maximal exercise capacity in the first 2 days after the blood donation.

19/10/2018

Autotransfusion d'hémothorax et Plyo: Prudence

A small amount can make a difference: a prospective human study of the paradoxical coagulation characteristics of hemothorax.

 
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Si la retransfusion d'un hémothorax traumatique apparaît être sécuritaire (1) et avoir un intérêt notamment en réduisant l'apport de CGR, le recours à cette pratique n'est pas encore totalement valide et apparaît encore réservé à des situations de pénurie extrême en dérivés sanguins (2). Il reste encore une incertitude sur son inocuité dès lors que l'on administre du plasma. C'est ce que met en évidence ce document qui est conforté par d'autres travaux (3). Il existerait en effet une situation d'hypercoagulabilité paradoxale y compris avec l'emploi de faibles doses de plasma. En conséquence  le recours à  l'autotransfusion de sang épanché doit il être bien réfléchi dans le cadre d'une stratégie plasma first associé à l'administration d'acide tranexaminique. 
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BACKGROUND:

The evacuated hemothorax has been poorly described because it varies with time, it has been found to be incoagulable, and its potential effect on the coagulation cascade during autotransfusion is largely unknown.

METHODS:

This is a prospective descriptive study of adult patients with traumatic chest injury necessitating tube thoracostomy. Pleural and venous samples were analyzed for coagulation, hematology, and electrolytes at 1 to 4 hours after drainage. Pleural samples were also analyzed for their effect on the coagulation cascade via mixing studies.

RESULTS:

Thirty-four subjects were enrolled with a traumatic hemothorax. The following measured coagulation factors were significantly depleted compared with venous blood: international normalized ratio (>9 vs 1.1) (P < .001) and activated partial thromboplastin time (aPTT) (>180 vs 24.5 seconds) (P < .001). Mixing studies showed a dose-dependent increase in coagulation dilutions through 1:8 (P < .05).

CONCLUSIONS:

An evacuated hemothorax does not vary in composition significantly with time and is incoagulable alone. Mixing studies with hemothorax plasma increased coagulation, raising safety concerns.

03/10/2018

Plaquettes et golden hour: Possible ?

Intravenous synthetic platelet (SynthoPlate) nanoconstructs reduce bleeding and improve 'golden hour' survival in a porcine model of traumatic arterial hemorrhage.

 

Traumatic non-compressible hemorrhage is a leading cause of civilian and military mortality and its treatment requires massive transfusion of blood components, especially platelets. However, in austere civilian and battlefield locations, access to platelets is highly challenging due to limited supply and portability, high risk of bacterial contamination and short shelf-life. To resolve this, we have developed an I.V.-administrable 'synthetic platelet' nanoconstruct (SynthoPlate), that can mimic and amplify body's natural hemostatic mechanisms specifically at the bleeding site while maintaining systemic safety.

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Previously we have reported the detailed biochemical and hemostatic characterization of SynthoPlate in a non-trauma tail-bleeding model in mice. Building on this, here we sought to evaluate the hemostatic ability of SynthoPlate in emergency administration within the 'golden hour' following traumatic hemorrhagic injury in the femoral artery, in a pig model. We first characterized the storage stability and post-sterilization biofunctionality of SynthoPlate in vitro. The nanoconstructs were then I.V.-administered to pigs and their systemic safety and biodistribution were characterized. Subsequently we demonstrated that, following femoral artery injury, bolus administration of SynthoPlate could reduce blood loss, stabilize blood pressure and significantly improve survival. Our results indicate substantial promise of SynthoPlate as a viable platelet surrogate for emergency management of traumatic bleeding.

30/07/2018

Vitamine C pour la coagulopathie du traumatisé sévère

Interventional Vitamin C: A Strategy for Attenuation of Coagulopathy and Inflammation in a Swine Polytrauma Model

Reynolds PS et Al. J Trauma Acute Care Surg. 2018 DOI:10.1097/TA.0000000000001844

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L'emploi de vitamine C à haute dose est connue dans le cadre de la réanimation du brûlé (1). Elle limiterait la fuite capillaire du fait de propriétés anti-oxydantes. Les auteurs rapportent un intérêt expérimental modéré mais prometteur à leur avis.

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BACKGROUND

Coagulopathy and inflammation induced by hemorrhagic shock and traumatic injury are associated with increased mortality and morbidity. Vitamin C (VitC) is an antioxidant with potential protective effects on the pro-inflammatory and pro-coagulant pathways. We hypothesized that high-dose VitC administered as a supplement to fluid resuscitation would attenuate inflammation, coagulation dysfunction, and end-organ tissue damage in a swine model of polytrauma and hemorrhage.


METHODS

Male Sinclair swine (n = 24; mean body weight 27 kg) were anesthetized, intubated, mechanically ventilated, and instrumented for physiological monitoring. Following stabilization, swine were subjected to shock/traumatic injury (hypothermia, liver ischemia and reperfusion, comminuted femur fracture, hemorrhagic hypotension), resuscitated with 500mL of hydroxyethyl starch, and randomized to receive either intravenous saline (NS), low dose VitC (50mg/kg; LO), or high dose VitC (200 mg/kg; HI). Hemodynamics, blood chemistry, hematology, and coagulation function (ROTEM) were monitored to 4 hours post-resuscitation. Histological and molecular analyses were obtained for liver, kidney, and lung.


RESULTS

Compared to VitC animals, NS swine showed significant histological end-organ damage, elevated acute lung injury scores, and increased mRNA expression of tissue pro-inflammatory mediators (IL-1, IL-8, TNF), PAI-1, and TF. There were no statistically significant differences between treatment groups on MAP or univariate measures of coagulation function; however, NS showed impaired multivariate clotting function at 4 hours.


CONCLUSIONS

Although correction of coagulation dysfunction was modest, intravenous high-dose VitC may mitigate the pro-inflammatory/pro-coagulant response that contributes to multiple organ failure following acute severe polytrauma.

25/07/2018

Plasma et MEDEVAC, Obligation ? OUI

Prehospital plasma during air medical transport in trauma patients at risk for  hemorrhagic shock.

Sperry JL et Al. N Engl J Med. 2018 Jul 26;379(4):315-326

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Confirmation par l'étude PAMPER de tout l'intérêt de l'apport préhospitalier précoce d'au moins deux unités de plasma. Cette étude porte sur plus de 500 traumatisés graves essentiellement fermés, surtout secondaires à des AVP avec tout de même une motralité qui paraît très élevée. Il semblerait que l'administration avant l'arrivée en structure chirurgicale  (mesurée dans ce travail à 1h) soit déterminante. Cependant, elle n'inclue que 20% de plaies pénétrantes sans faire mention d'IED, ce qui limite fortement une extrapolation simple aux blessés par arme de guerre., ce d'autant que le tableau 2 montre que dans ce sous groupe le traitement conventionnel ferait mieux en terme de survie. Un éditorial abordant les problématiques "logistiques" liée à l'emploi du plasma accompagne cette publication (1). Lire également (23).

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BACKGROUND:

After a person has been injured, prehospital administration of plasma in addition to the initiation of standard resuscitation procedures in the prehospital environment may reduce the risk of downstream complications from hemorrhage and shock. Data from large clinical trials are lacking to show either the efficacy or the risks associated with plasma transfusion in the prehospital setting.

METHODS:

To determine the efficacy and safety of prehospital administration of thawed plasma in injured patients who are at risk for hemorrhagic shock, we conducted a pragmatic, multicenter, cluster-randomized, phase 3 superiority trial that compared the administration of thawed plasma with standard-care resuscitation during air medical transport. The primary outcome was mortality at 30 days.

RESULTS:

A total of 501 patients were evaluated: 230 patients received plasma (plasma group) and 271 received standard-care resuscitation (standard-care group). Mortality at 30 days was significantly lower in the plasma group than in the standard-care group (23.2% vs. 33.0%; difference, -9.8 percentage points; 95% confidence interval, -18.6 to -1.0%; P=0.03). A similar treatment effect was observed across nine prespecified subgroups (heterogeneity chi-square test, 12.21; P=0.79). Kaplan-Meier curves showed an early separation of the two treatment groups that began 3 hours after randomization and persisted until 30 days after randomization (log-rank chi-square test, 5.70; P=0.02). The median prothrombin-time ratio was lower in the plasma group than in the standard-care group (1.2 [interquartile range, 1.1 to 1.4] vs. 1.3 [interquartile range, 1.1 to 1.6], P<0.001) after the patients' arrival at the trauma center. No significant differences between the two groups were noted with respect to multiorgan failure, acute lung injury-acute respiratory distress syndrome, nosocomial infections, or allergic or transfusion-related reactions.

CONCLUSIONS:

In injured patients at risk for hemorrhagic shock, the prehospital administration of thawed plasma was safe and resulted in lower 30-day mortality and a lower median prothrombin-time ratio than standard-care resuscitation. 

| Tags : coagulopathie