Safe and Efficacious Near Superhydrophobic Hemostat for Reduced Blood Loss and Easy Detachment in Traumatic Wounds

Hemorrhage is the leading cause of trauma death, and innovation in hemostatic technology is important. The strongly hydrophobic carbon nanofiber (CNF) coating has previously been shown to have excellent hemostatic properties. However, the understanding of how CNF coating guides the coagulation cascade and the biosafety of CNF as hemostatic agents has yet to be explored. Here, our thrombin generation assay investigation showed that CNF induced fast blood coagulation via factor (F) XII activation of the intrinsic pathway. We further performed studies of a rat vein injury and demonstrated that the CNF gauze enabled a substantial reduction of blood loss compared to both the plain gauze and kaolin-imbued gauze (QuikClot). Analysis of blood samples from the model revealed no acute toxicity from the CNF gauze, with no detectable CNF deposition in any organ, suggesting that the immobilization of CNF on our gauze prevented the infiltration of CNF into the bloodstream. Direct injection of CNF into the rat vein was also investigated and found not to elicit overt acute toxicity or affect animal survival or behavior. Finally, toxicity assays with primary keratinocytes revealed minimal toxicity responses to CNF. Our studies thus supported the safety and efficacy of the CNF hemostatic gauze, highlighting its potential as a promising approach in the field of hemostatic control.

Thromboelastometry guided therapy of severe bleeding. Essener Runde algorithm

Both, severe haemorrhage and blood transfusion are associated with increased morbidity and mortality. Therefore, it is of particular importance to stop perioperative bleeding as fast and as possible to avoid unnecessary transfusion. Viscoelastic test (ROTEM® or TEG®) allow for early prediction of massive transfusion and goal-directed therapy with specific haemostatic drugs, coagulation factor concentrates, and blood products. Growing consensus points out, that plasma-based coagulation screening tests like aPTT and PT are inappropriate for monitoring coagulopathy or guide transfusion therapy. Increasing evidence of more than 5000 surgical or trauma patients points towards the beneficial effects of a thrombelastography or -metry based approach in diagnosis and goal-directed therapy of perioperative massive haemorrhage. The Essener Runde task force is a group of clinicians of various specialties (anaesthesiology, intensive care, haemostaseology, haematology, internal medicine, transfusion medicine, surgery) interested in perioperative coagulation management. The ROTEM diagnostic algorithm of the Essener Runde task force was created to standardise and simplify the interpretation of ROTEM® results in perioperative settings and to present their possible implications for therapeutic interventions in severe bleeding. To exemplify, this text mainly focuses on coagulation management in trauma.

Coagulation management in multiple trauma: a systematic review

PURPOSE

The management of trauma patients suffering from active bleeding has improved with a better understanding of trauma-induced coagulopathy. The aim of this manuscript is to give recommendations for coagulation management.

METHODS

A systematic literature search in the PubMed database was performed for articles published between January 2000 and August 2009. A total of 230 articles were included in the present systematic review.

CONCLUSIONS

The "coagulopathy of trauma" is a discrete disease which has a decisive influence on survival. Diagnosis and therapy of deranged coagulation should start immediately after admission to the emergency department. A specific protocol for massive transfusion should be introduced and continued. Loss of body temperature should be prevented and treated. Acidaemia should be prevented and treated by appropriate shock therapy. If massive transfusion is performed using fresh frozen plasma (FFP), a ratio of FFP to pRBC (packed red blood cells) of 1:2-1:1 should be achieved. Fibrinogen should be substituted at levels of <1.5 g/L. For patients suffering from active bleeding, permissive hypotension (i.e. mean arterial pressure ~65 mmHg) may be aimed for until surgical cessation of bleeding. This option is contraindicated in injuries of the central nervous system and in patients with coronary heart disease, or with known hypertension. Thrombelastography or -metry may be performed to guide coagulation diagnosis and substitution. Hypocalcaemia <0.9 mmol/L should be avoided and may be treated. For actively bleeding patients, pRBC may be given at haemoglobin <10 g/L (6.2 mmol/L) and haematocrit may be targeted at 30%.

[Coagulation management in the treatment of multiple trauma]

In recent years a new understanding of trauma-associated hemorrhaging and trauma-induced coagulopathy has been achieved. This coagulopathy is multifactorial with the predominant mechanisms being tissue trauma, shock and hypoperfusion which can lead to hyperfibrinolysis by activation of the endothelium. Routinely tested coagulation parameters, such as prothrombin time and partial thromboplastin time, are frequently employed for decision making but remain problematic as they do not give any information on clot stability, lysis or platelet function. Thrombelastometry seems to be a useful alternative. A pro-active anticipatory approach is required for a successful outcome to be achieved as rescue correction is more difficult than prevention. While the pathophysiological conception of causal relationship of the mentioned therapeutic options is conclusive, an evidence-based validation by randomized controlled studies is mostly lacking. The emergency and anesthesiological concept of damage control resuscitation consists of limiting volume therapy with crystalloids and colloids to reach a mean arterial pressure > or =65 mmHg (higher for head injuries), active (re-)warming management, the prevention of a pH< or =7.2 and a base excess (BE) < or =-6 mmol/l. The early and sufficient application of hemostatic drugs is essential. Because erythrocytes play a substantial role in the coagulation process, hemoglobin (Hb) values of around 6. 2 mmol/l (10 g/dl) and/or a hematocrit of 30% should be strived for when massive non-arrested hemorrhaging occurs. After severe multiple trauma a fibrinogen deficit develops and must be adequately compensated. If coagulation therapy is carried out using fresh frozen plasma sufficient quantities (20-30 ml/kgBW) must be administered to correspondingly raise the coagulation factors. Prothrombin complex concentrates can be helpful to optimize thrombin generation during severe hemorrhaging. Because hyperfibrinolysis occurs more often than previously assumed during severe trauma, an anti-fibrinolytic therapy should be used especially for patients with an instable circulation. The platelet count should not go below 100,000/microl when hemorrhaging occurs after multiple trauma. For thrombocytopathic patients with diffuse bleeding desmopressin (DDAVP) is a therapeutic option and the "off label" use of recombinant activated factor VIIa (rFVIIa) remains an option for individual situations with stringent indications and when the above named measures to optimize the coagulation situation have been taken.