Flow dilution effect on blood coagulation in vivo

Enzyme reaction model of flow dilution effect on blood coagulation in viv

Mathematical Modeling of Blood Coagulation

Blood coagulation is a series of biochemical reactions that take place to form a blood clot. Abnormalities in coagulation, such as under-clotting or over- clotting, can lead to significant blood loss, cardiac arrest, damage to vital organs, or even death. Thus, understanding quantitatively how blood coagulation works is important in informing clinical decisions about treating deficiencies and disorders. Quantifying blood coagulation is possible through mathematical modeling. This review presents different mathematical models that have been developed in the past 30 years to describe the biochemistry, biophysics, and clinical applications of blood coagulation research. This review includes the strengths and limitations of models, as well as suggestions for future work

Studies on the Blood Coagulation Mechanisms of Different Species Compared to Man, Volume One

Blood coagulation has been investigated in lobsters, fowl, cattle, horses, and rabbits. Comparison has been made with the human blood coagulation mechanism, on the basis of current concepts of that system

Blood coagulation from the beginning until to-day

The authors give an account of the important developments in blood coagulation knowledge from the times of Malpighi and Moravitz to data. The article is followed by original tables providing a general and comprehensive view on blood coagulation, hemorrhagic syndromes and fibrinolysis.</p

Effects of hemoglobin-based oxygen carriers on blood coagulation.

For many decades, Hemoglobin-based oxygen carriers (HBOCs) have been central in the development of resuscitation agents that might provide oxygen delivery in addition to simple volume expansion. Since 80% of the world population lives in areas where fresh blood products are not available, the application of these new solutions may prove to be highly beneficial (Kim and Greenburg 2006). Many improvements have been made to earlier generation HBOCs, but various concerns still remain, including coagulopathy, nitric oxide scavenging, platelet interference and decreased calcium concentration secondary to volume expansion (Jahr et al. 2013). This review will summarize the current challenges faced in developing HBOCs that may be used clinically, in order to guide future research efforts in the field

Effects on coagulation of balanced (130/0.42) and non-balanced (130/0.4) hydroxyethyl starch or gelatin compared with balanced Ringer's solution: an in vitro study using two different viscoelastic coagulation tests ROTEM™ and SONOCLOT™†

Background Hydroxyethyl starch (HES) solutions compromise blood coagulation. Low molecular weight, low-substituted HES products, and electrolyte-balanced solutions might reduce this effect. We compared the effects of in vitro haemodilution on blood coagulation with a balanced 6% HES 130/0.42 solution (HESBAL), a saline-based 6% HES 130/0.4 solution (HESSAL), a balanced lactated Ringer's solution (RL) and a saline-based 4% gelatin solution (GEL). Methods Blood was obtained from 10 healthy male volunteers and diluted with the test solutions by 33% and 66%. Quality of clot formation was measured using two viscoelastic coagulation tests: SONOCLOT™ and activated rotation thromboelastometry ROTEM™. Results Of 16 parameters measured by the viscoelastic devices, we found three statistically significant differences compared with baseline for RL, but 11 for GEL, 10 for HESSAL, and 11 for HESBAL in the 33% haemodilution group (P=0.01). Comparing the different solutions, we observed a significant difference between crystalloids and colloids but none between GEL and HES. In the 66% dilution group, effects on blood coagulation were increased when compared with the 33% dilution group. We found no differences in coagulation impairment between balanced and non-balanced HES products and no differences in the detection of impaired blood coagulation due to haemodilution between the two viscoelastic coagulation tests. Conclusions Both ROTEM™ and SONOCLOT™ are sensitive tests for the detection of impaired blood coagulation due to haemodilution. There are fewer effects on blood coagulation using crystalloids compared with colloids. The effects of GEL and HES are similar. There is no difference between balanced HES 130/0.42 and non-balanced HES 130/0.

Panel of Regulatory miRNAs for Blood Coagulation under Normoxic and Hypoxic Conditions

Abnormal blood coagulation may lead to venous thromboembolism (VTE), a complex multifactorial disease. Hypoxia (oxygen deprivation) is a major factor disturbing the blood hemostasis and predisposing the body towards coagulation and VTE. Pathophysiology of VTE can be attributed to post-transcriptional gene regulation by microRNAs (miRNAs). The present study identified regulatory miRNAs involved in causing blood coagulation under normoxic and hypoxic conditions. Meta-analysis was performed, following PRISMA guidelines, for identifying miRNAs involved in blood coagulation pathway. Studies evaluating miRNAs from circulating blood as potential biomarkers of VTE were selected. A total of 16 studies met selection criteria and 8 having complete statistical information were selected for analysis. Study of blood coagulation mechanism under hypoxic conditions involved in-silico search within highly cited databases to identify miRNAs commonly regulating genes of hypoxia-inducible factor (HIF) family and coagulation pathway. Further bio-informatics approaches were employed to identify potential biomarker candidates. Meta-analysis revealed a panel of 12 miRNAs; two members of miR-27 family, hsa-miR-27a and hsa-miR-27b; two members of miR-320 family, hsa-miR-320a and hsa-miR-320b, hsa-miR-1233, hsa-miR-134, hsa-miR-424-5p, hsa-miR-221, hsa-miR-28-3p, hsa-miR-136-5p, hsa-miR-374-5p and hsa-miR-338-5p involved in blood coagulation under normoxic conditions. Besides these, present in-silico analysis identified a set of 5 miRNAs including hsa-miR-4667-5p, hsa-miR-6815-3, hsa-miR-4433a-3p, hsa-miR-6735-5p and hsa-miR-6777-3p which predominantly regulate genes that facilitate both coagulation and response to hypoxic stress. The present study generated a panel of regulatory miRNAs potentially involved in the process of blood coagulation under both normoxic and hypoxic conditions, which may serve as putative epigenetic biomarkers for coagulation

Molar substitution and C2/C6 ratio of hydroxyethyl starch: influence on blood coagulation

Background. Development of hydroxyethyl starches (HES) with a low impact on blood coagulation but a long intravascular persistence is of clinical interest. A previous in vitro study showed that low substituted high molecular weight HES does not compromise blood coagulation more than medium molecular weight HES. In the present study we assessed the individual effects on blood coagulation of molar substitution and C2/C6 ratio of a high molecular weight HES. Methods. Blood was obtained from 30 healthy patients undergoing elective surgery and mixed with six high molecular weight (700 kDa) HES solutions differing in their molar substitution (0.42 and 0.51) and C2/C6 ratio (2.7, 7 and 14) to achieve 20, 40 and 60% dilution. Blood coagulation was assessed by Thrombelastograph® analysis (TEG) and plasma coagulation tests.Data were compared using a three-way analysis of variance model with repeated measures on the three factors. Results. Higher molar substitution compromised blood coagulation most (for all TEG parameters, P0.50). The higher molar substitution was associated with a lesser increase in PT (P=0.007) and a greater decrease in factor VIII (P=0.010). PTT, functional and antigenic von Willebrand factors were not significantly influenced by molar substitution (P for all >0.20). No significant differences between solutions with the same molar substitution but different C2/C6 ratios were found in plasma coagulation parameters (P for all >0.05). Conclusions. TEG analysis indicates that high molecular HES with a molar substitution of 0.42 and a C2/C6 ratio of 2.7 has the lowest effect on in vitro human blood coagulatio

Intraoperative changes in blood coagulation and thrombelastographic monitoring in liver transplantation

The blood coagulation system of 66 consecutive patients undergoing consecutive liver transplantations was monitored by thrombelastograph and analytic coagulation profile. A poor preoperative coagulation state, decrease in levels of coagulation factors, progressive fibrinolysis, and whole blood clot lysis were observed during the preanhepatic and anhepatic stages of surgery. A further general decrease in coagulation factors and platelets, activation of fibrinolysis, and abrupt decrease in levels of factors V and VIII occurred before and with reperfusion of the homograft. Recovery of blood coagulability began 30-60 min after reperfusion of the graft liver, and coagulability had returned toward baseline values 2 hr after reperfusion. A positive correlation was shown between the variables of thrombelastography and those of the coagulation profile. Thrombelastography was shown to be a reliable and rapid monitoring system. Its use was associated with a 33% reduction of blood and fluid infusion volume, whereas blood coagulability was maintained without an increase in the number of blood product donors