Response of the coagulation system after application of hemostatic dressings in an animal model

The Effect of Haemostatic Dressing Prototypes for the Emergency Services in the Porcine Haemostatic System

BACKGROUND/AIM

Coagulopathy can develop when hemostatic dressings are used to stop massive bleeding, even in patients without prior history of clotting disorders. The selection of procoagulants, which effectively control bleeding and prevent disseminated intravascular coagulation (DIC) and thrombosis, is a significant challenge. The aim of this study was to evaluate the effect of two prototypes of haemostatic dressing in the porcine haemostatic system.

MATERIALS AND METHODS

The total number of animals used in our experiments was 24. Group I: pigs were treated with the developed prototype of sponge dressing, made of Na-Ca chitosan/algal composite of microfibers and nanofibers. Group II: animals were treated with a seton gauze modified with a polymer mixture of Na-Ca chitosan/algal composite of microfibers and nanofibers. Group III: animals were treated with non-hemostatic dressing and this group was the control. Blood was sampled five times to determine changes in the coagulation and fibrinolytic profiles: before injury: i) at 1 h, ii) at 24 h, iii) at 7, and iv) at 14 days following injury.

RESULTS

Significant changes were observed in the coagulation parameters, in the total numbers of white blood cells and platelets in groups I and II, compared to controls.

CONCLUSION

The modified haemostatic dressings used in this study produced a strong procoagulant effect in pigs. This, together with high fibrinogen concentrations, which can cause DIC, require further studying.

The effect of hemostatic dressing prototypes for the uniformed services on selected blood coagulation parameters in pigs

Background

Serious injuries accompanied by severe bleeding are life-threatening. Post-traumatic hemorrhage involves the risk of developing coagulopathy. Hemostatic dressings are widely used to minimize bleeding. The application of procoagulants in control of hemorrhage may lead to thrombosis or disseminated intravascular coagulation. The aim of this study was to evaluate the effect of hemostatic dressing prototypes on the porcine coagulation system.

Results

Fibrinogen and d-dimer concentrations were significantly higher in the experimental groups where hemostatic dressings were used in comparison with the control group. Considerable differences in antithrombin III activity and thrombin–antithrombin complex concentrations were also observed between groups.

Conclusions

The hemostatic dressing comprising modified seton impregnated with 18.0 g/m² of procoagulant was most effective in preserving the physiological equilibrium between fibrinogenesis and fibrinolysis.

Thromboelastographic profile of goat blood after the experimental injury of the femoral artery and use of QuikClot gauze and Celox gauze dressings

The aim of this study was to evaluate the suitability of thromboelastometry for the analysis of blood test results in goats after the use of hemostatic dressings to control massive bleeding. The study was carried out on 12 goats, 6 animals in each of two subgroups. In all experimental animals incision of the femoral artery was performed, and bleeding was controlled with QuikClot gauze in the first group and Celox gauze in the second group. Dressings were applied for 60 minutes. Blood samples for thromboelastometry were collected from the jugular vein before the incision and 60 min after the application of a dressing. Clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF) and α angle (°) were measured in three standard ROTEM assays (system with generation of reaction curve, numerical parameters and size of the blood clot): intrinsic coagulation pathway (INTEM), extrinsic coagulation pathway (EXTEM) and functional fibrinogen (FIBTEM). Complete hemostasis of the injured femoral artery was found in all goats. No significant differences between pre- and post-incision thromboelastometric parameters were found in any tests in any of the groups, which indicates that the use of dressings was not associated with blood coagulation disorders. This study is the first to describe the use of thromboelastometry in goats for the assessment of clot formation and hemostatic disorders.

The Effectiveness of Modified Seton and Modified Combat Gauze in Controlling Severe Hemorrhaging during Operations of Uniformed Services

Hemorrhaging from large vessels poses a serious problem in emergency situations when blood loss needs to be immediately controlled. The aim of the study was to compare the effectiveness of two hemostatic dressings in controlling bleeding from a surgically punctured femoral artery. The study was performed on thirteen pigs divided into two groups, of six and seven pigs, respectively. Combat gauze covered with ChitoClear hqg 95 chitosan and Protanal LF10/60 FT sodium alginate was used in the first group, seton covered with identical substances was uses in the second group. Selected hemostatic dressing was applied to the wound 20 seconds after incision and then removed at regular time intervals to evaluate hemostasis. Modified seton was characterized by a shorter time to hemostasis than combat gauze. The result of this experiment indicate that modified seton proved to be a more effective dressing than modified combat gauze.

Safety of the long-term application of QuikClot Combat Gauze, ChitoGauze PRO and Celox Gauze in a femoral artery injury model in swine - a preliminary study

The purpose of this study was to examine the safety of the long-term application of QuikClot Combat Gauze, ChitoGauze PRO and Celox Gauze using a swine model. The study was conducted on nine pigs weighing approximately 30 kg, which were randomly divided into three groups. Under deep anesthesia, the pigs underwent complete transverse cutting of the femoral artery in the groin region. Hemostatic dressings were left in the wound for 24 hours. The animals were euthanized 24 hours after dressing application. In each group, macroscopic and microscopic severe changes and shock symptoms were observed in the lungs, liver, kidneys and heart. Fibrino-gaseous embolic material was found in the pulmonary artery of each group and in the lung vessels of the animals from the ChitoGauze PRO and Celox Gauze groups. In conclusion, the long-term application of the evaluated hemostatic dressings has the risk of coagulopathy and reaching the progressive stage of shock. The residues from the hemostatic dressings can ingress into the systemic circulation, thereby increasing the risk of embolus formation. Because of these harmful effects, the evaluated hemostatic dressings are not appropriate for long-term use. Future studies are needed on the consequences of the long-term application of these hemostatic agents.

The using of a piglets as a model for evaluating the dipyrone hematological effects

BACKGROUND

Dipyrone (MET, metamizole) is a non-steroidal anti-inflammatory drug commonly used both in human and in veterinary medicine. After oral administration, is broken down rapidly to metabolites which largely retain the activity of the parent drug. Its metabolites have analgesic, antipyretic and anti-inflammatory effects.

RESULTS

The subjects were eight healthy male Large White post-suckling piglets, weighing between 5.0 to 7.4 kg, of ages 35 ± 10 days. The animals were administered MET (100 mg/kg) by an intramuscular (I.M.) injection. The study calculated the value of several hemorheological parameters. Significant impact of MET treatment (p < 0.05) was proven in case: activated partial thromboplastin time; ratio of activated partial thromboplastin time; hemoglobin; hematocrit; mean corpuscular hemoglobin; mean corpuscular volume; red blood cells volume; white blood cells volume; prothrombin time index.

CONCLUSIONS

In summation, our observations suggest that a piglet model is useful for studying the impact of MET on hemorheological parameters.