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PubMed1978

Disseminated intravascular multiple systems activation (DIMSA) following thermal injury.

Seventy-seven major thermal injury victims were studied with a number of hematologic and immunologic tests initially and sequentially during the first postburn month. The patients were grouped by initial prognostic index as well as by ultimate survival. Pairs were grouped by initial prognostic index as well as by ultimate survival. Pairs of test data from subjects studied at successive time intervals were compared with prognostic index and ultimate survival. Statistically significant changes in coagulation, fibrinolytic, complement, and kinin tests all occurred within these groups. These findings strongly suggest that intravascular contamination occurs following thermal injury in proportion to the extent of the burn, because of the occurrence and persistence of statistically significant multiple system changes. Regrouping all of the blood data according to ultimate death or survival reinforced the concept of intravascular contamination and provided the basis by which one can compute laboratory prognostic indices. The combination of plasminogen, C'3 complement, C'H50, one-minute kinin, and TEG index discriminated between death and survival with 91% accuracy by the end of the first postburn week. These data offer the potential for select blood measurements in refining current prognostic indicators. This may provide an objective data base for the analysis of new treatment programs in thermal injury victims.

Blood Cell Count↗
PubMed1995

Hemostatic competency and elastase-alpha 1-proteinase inhibitor levels in surgery, trauma, and sepsis.

Previous studies investigated the effects of neutrophil elastase on isolated factors in the hemostatic process. Some of these reported effects are, however, procoagulative and others anticoagulative. The aim of this study was to ascertain the effect of elastase on the in vivo hemostatic competency. The effect of elastase activity on the hemostatic competency was determined in a group of 50 surgical intensive care unit patients and 23 control subjects. Surgical intensive care unit patients were subgrouped into a surgery, a trauma, and a sepsis-multiple organ failure group. Elastase activity was assessed by elastase-alpha 1-proteinase inhibitor levels and hemostatic competency by thromboelastography. Thromboelastography results showed a relatively normal coagulative ability in the surgery group, a varying degree of thromboelastographic hypocoagulability in the trauma group, and pronounced thromboelastographic instability in the sepsis-multiple organ failure group. Increases in elastase-alpha 1-proteinase inhibitor levels up to 200 micrograms/L were accompanied by a compromised coagulative ability as seen in a prolongation of both the first and second phases of the clotting time, as well as a decrease in the maximal clot elasticity.

Case-Control Studies↗
PubMed1977

Thromboelastographic distinction of malignant from benign breast masses: a preliminary report.

Thromboelastography is a newly applied tool for the detection of carcinoma. By comparing the thromboelastograph (TEG) of fresh whole blood (native) to that of blood to which celite has been added (celite activated), enhanced clotting is manifested which allows identification of individuals harboring carcinoma. Twenty women, obtained in a random sampling, entering the North Carolina Baptist Hospital for biopsy of breast masses were studied with routine clotting tests and TEGs preoperatively. TEG prediction of the biopsy result was correct in 16 of 20 patients (P less than 0.05). Thromboelastography may be a useful adjunct in screening for carcinoma in the evaluating persons with masses of unknown histology.

Blood Coagulation Tests↗
PubMed1998

Effectiveness of conjugated estrogen in orthotopic liver transplantation.

BACKGROUND: A retrospective study was conducted at a university hospital to determine the efficacy of conjugated estrogen in reducing blood product transfusion during orthotopic liver transplantation. METHODS: The charts of patients who had orthotopic liver transplantation were retrospectively reviewed. Only those having a reaction time > 30 mm or 15 minutes (normal = 19 mm to 28 mm) on computerized thromboelastogram (CTEG) at the beginning of surgery were included. One group of patients received a first dose of conjugated estrogen (100 mg i.v.) at the beginning of the case and a second dose (100 mg i.v.) just after reperfusion of the new graft. The control group did not receive estrogen. The two groups were similar in age, weight, first TEG measurements, final intraoperative hemoglobin concentration and platelet count. Blood products were given in response to hematocrit and CTEG measurements, which were determined every hour during surgery. RESULTS: The two groups did not differ in units of cryoprecipitate and platelets administered, but the intraoperative requirements for red blood cells and fresh frozen plasma were significantly lower in the estrogen group than in the control group. CONCLUSIONS: Administration of conjugated estrogen is associated with a statistically significant decrease in use of red blood cells and fresh frozen plasma during orthotopic liver transplantation.

Adult↗
PubMed2001

The efficacy of antifibrinolytics in the reduction of blood loss during complex adult reconstructive spine surgery.

STUDY DESIGN: Controlled study to assess the efficacy of aprotinin and Amicar in reducing blood loss during complex spinal fusions. OBJECTIVES: To compare blood loss and the clotting profile with a thromboelastogram in patients with spinal deformities undergoing sequential anterior and posterior spinal fusions treated intraoperatively with either aprotinin or Amicar. SUMMARY OF BACKGROUND DATA: Spinal fusion for correction of adult spinal deformities is associated with large blood losses despite the implementation of multiple factors to reduce this blood loss. The antifibrinolytics aprotinin and Amicar have both been shown to reduce blood loss in other surgical procedures with the potential for large blood loss. Hence, we compared their efficacy for reducing blood loss in complex spinal fusions. METHODS: Sixty patients for elective sequential anteroposterior thoracolumbosacral fusions were randomly assigned to three groups: control, aprotinin, and Amicar. Patients were assessed for blood loss, transfusion requirements, postoperative complications, and coagulation profile using a thromboelastogram. RESULTS: The study demonstrated a significant reduction in total blood loss (aprotinin 3628 mL, Amicar 4056 mL, control 5181 mL) and transfusion requirements using the half-dose aprotinin regimen compared with Amicar or control. Aprotinin also preserved the thromboelastogram mean clot formation time, clot strength, and clotting index compared with Amicar or control. CONCLUSIONS: For complex spinal operations with large blood losses, the half-dose aprotinin regimen will reduce blood loss and the need for blood components and may have a role in reducing postoperative lung injury.

Aminocaproic Acid↗
PubMed1999

Bleeding induced interleukin-6 decreases blood loss via activation of coagulation.

Hemorrhage is known to induce the production of inflammatory cytokines such as interleukin-6 (IL-6). IL-6 plays an intermediate role as a factor in the activation of coagulation cascade and exerts a lethal effect in sepsis. To examine the effect of endogenous IL-6 on blood loss, we performed four experiments in female ddY mice. Enzyme immunoassay using an uncontrolled hemorrhage model, i.e., 75% tail resection, revealed the production of serum IL-6 (Experiment 1). We also measured cumulative blood loss and survival rate (Experiment 2); measured blood pressure and performed thrombelastogram (TEG) (Experiment 3); and measured plasma thrombin-antithrombin III (TAT) complex levels in two groups, one pretreated with 1 mg of anti-IL-6 monoclonal antibody (mAb), and one with normal rat globulin (NRG) using the same model (Experiment 4). The mAb group showed a significantly higher blood loss than the NRG group. All mice survived for 5 days in both groups. Blood pressure did not differ between either group. The TEG results suggest that administration of anti-IL-6 mAb caused mild suppression of coagulation activation, but did not affect fibrinolysis or platelets. In the mAb group, plasma TAT complex concentrations showed a significant decrease compared with the NRG group. In conclusion, hemorrhage-induced IL-6 may contribute to hemostasis through activation of coagulation, thus reducing blood loss.

Animals↗
PubMed2006

Increased lactate levels impair the coagulation system--a potential contributing factor to progressive hemorrhage after traumatic brain injury.

Progressive intracerebral contusions are a major problem in the management of patients with severe traumatic brain injury that is also linked to worse outcome. Microdialysis studies have revealed that lactate levels are very high inside contusions, corresponding to significant acidosis. The current study was performed in an effort to investigate whether the lactate accumulation inside cerebral contusions may be a contributing factor to the prolonged bleeding inside contusions. We have investigated the effects of lactic acidosis on the coagulation system with rotational thromboelastometry. It was a laboratory study involving 6 healthy volunteers. Blood was drawn and the pH was adjusted by addition of lactic acid in vitro. The pH levels studied were 7.4, 7.2, 7.0, and 6.8. The pH was also readjusted to 7.4 by addition the buffer THAM to blood initially adjusted to a pH of 6.8 to study the reversibility of potential adverse effects induced by the lactic acidosis. We found the coagulation to be significantly impaired by lactic acidosis (P = 0.000l). The impairment found was reversible after correction of the acidosis by a buffer. In conclusion, we found that lactic acidosis impaired the coagulation system. The impairment caused by lactic acidosis may be one factor causing the progressive hemorrhage in posttraumatic cerebral contusions, known to have high levels of lactate and correspondingly low pH. It may also be important to consider in bleeding trauma patients.

Acidosis↗
PubMed2004

Clotting parameters and thromboelastography in children with neuromuscular and idiopathic scoliosis undergoing posterior spinal fusion.

STUDY DESIGN: An unblinded comparison of laboratory values between patients with idiopathic and neuromuscular scoliosis. OBJECTIVES: To compare standard tests of coagulation and thromboelastography (TEG) parameters between two groups of patients undergoing posterior spinal fusion (PSF). SUMMARY OF BACKGROUND DATA: Children with neuromuscular scoliosis such as cerebral palsy have more intraoperative blood loss than children with idiopathic scoliosis during PSF. Various reasons suggested for this include nutritional deficiencies, altered tissue integrity, hepatic dysfunction, and use of antiepileptic medications that can cause poor hemostasis and altered coagulation. We have observed alterations in coagulation factor levels in patients with cerebral palsy due to spastic quadriplegia with moderate blood volume loss (25% estimated blood volume). METHODS: In a prospective analysis, we compared standard tests of coagulation (prothrombin time [PT], partial thromboplastin time [PTT], platelet count, fibrinogen levels) and TEG at baseline and at a blood loss of 15% estimated blood volume in patients with idiopathic scoliosis and cerebral palsy undergoing PSF. RESULTS: There were no differences between the groups in terms of gender distribution and age. There was a significant difference between the baseline PT and PTT values, although both groups were within laboratory norms. After 15% blood volume loss, there were differences seen in the PT, PTT, maximum amplitude on the TEG, ionized calcium, and serum magnesium levels (P < 0.05). CONCLUSIONS: Children with cerebral palsy undergoing PSF have increased bleeding that starts earlier in the procedure than it does for patients with idiopathic scoliosis undergoing PSF. We found that, even though children with spastic quadriplegia had baseline PT and PTT values within normal limits, they were significantly different when compared with normal patients.

Adolescent↗
PubMed2005

Multi-centre investigation on reference ranges for ROTEM thromboelastometry.

Reagent-supported thromboelastometry (TEM) with the ROTEM Whole Blood Haemostasis Analyser is an enhancement of thromboelastography, a method that is increasingly used for the point of care monitoring of acute perioperative bleeding disorders. We investigated the reference ranges of two activated tests (INTEM and EXTEM) and a test analysing specifically the fibrin component of coagulation (FIBTEM) in a multi-centre approach. The reference ranges obtained for the clotting time (CT), clot formation time (CFT), alpha angle (ALP), maximum clot firmness (MCF) and clot lysis parameters were comparable from centre to centre. INTEM: CT equals; 137-246 s, CFT equals; 40-100 s, MCF equals; 52-72 mm. EXTEM: CT equals; 42-74 s, CFT equals; 46-148 s, MCF equals; 49-71 mm. FIBTEM: MCF equals; 9-25 mm. ROTEM whole blood coagulation correlated weakly with a trend towards enhanced coagulation in females compared with males and in advanced age. The repeatability (within-run imprecision) of the results was dependent on the test with the following coefficients of variation: 1-5% (clot firmness, alpha angle), 3-12% (CT, CFT), 6-13% (FIBTEM clot firmness). Citrated blood samples were stable for ROTEM analysis stored within 6 h from drawing. In summary, the data showed that ROTEM thromboelastometry yields consistent values between centres and that providing general orientating reference ranges seems to be possible.

Age Factors↗
PubMed2005

An evaluation of the procoagulant action of recombinant activated factor VII in cord whole blood versus adult whole blood using thromboelastography.

Recombinant activated factor VII (rFVIIa) has been reported to be effective in adult patients in various clinical situations and might be beneficial in neonates with bleeding tendency. In the present study we compared the procoagulant action of increasing amounts of rFVIIa in both cord whole blood and adult whole blood with respect to changes in the values of the clotting time, clot formation time, and maximum clot firmness by means of thromboelastography. Thromboelastography allows evaluation of the effects of rFVIIa on haemostasis in whole blood. When increasing amounts of rFVIIa were added in vitro to whole blood samples, significant decreases in the values of the clotting time and clot formation time and a significant increase in the maximum clot firmness were observed. Cord whole blood was significantly more sensitive to rFVIIa addition than adult whole blood, an effect probably attributable to the low anticoagulant capacity of the neonatal plasma. Maximum clot firmness values were significantly lower in cord whole blood than in adult whole blood, an effect mainly attributable to the hypofunctional state of neonatal platelets. Since cord whole blood exerted a significantly higher sensitivity to addition of rFVIIa, we speculate that lower doses of rFVIIa might be required to treat neonates with bleeding tendency compared with the adult rFVIIa administration strategy.

Adult↗
PubMed2006

The effect of N-acetylcysteine on blood coagulation and platelet function in patients undergoing open repair of abdominal aortic aneurysm.

N-acetylcysteine (NAC) may offer renal and hepatic protection during surgery, but in experimental studies it has been shown to impair coagulation. Since very little is known about the effects of NAC on blood coagulation in surgical patients, we studied its effects during abdominal aortic reconstruction. NAC (a bolus of 150 mg/kg followed by a continuous 24-h infusion of 150 mg/kg) or the same volume of placebo was given intravenously, in a randomized double-blinded fashion, to 20 patients undergoing abdominal aortic aneurysm repair. The haematocrit, platelet count, prothrombin time, thromboelastometry, and platelet aggregation were studied during and after surgery. Total blood loss was also measured. The median (25th-75th percentiles) decrease of the prothrombin time value was 33.0% (30-37%) after NAC treatment and 6.5% (4-8%) after placebo (P<0.001). Postoperative prothrombin time values remained lower in the patients receiving NAC. In thromboelastometry tracings the coagulation time was more prolonged after the bolus of NAC (P=0.02). Platelet aggregation induced with adenosine diphosphate decreased after NAC but not after placebo. Low prothrombin time values before and after bolus infusions were associated with increased blood loss (P=0.008 and P=0.015, respectively). NAC has anticoagulant and platelet-inhibiting properties in patients undergoing major vascular surgery. This abnormal haemostatic activity should be considered when NAC is administered to patients with increased bleeding risk.

Acetylcysteine↗
PubMed2006

Elastic modulus-based thrombelastographic quantification of plasma clot fibrinolysis with progressive plasminogen activation.

Thrombelastographic detection of fibrinolysis has been critical in the identification and treatment of coagulopathy in many perioperative settings. However, the fibrinolytic assessments have been at best non-parametric, amplitude-based determinations (e.g. estimated % lysis, clot lysis time or clot lysis rate). Recognizing this limitation, a methodology was developed to measure the onset, speed and extent of clot disintegration by changes in elastic modulus derived from the amplitude. Using this approach, our goal was to characterize the clot disintegration kinetics of progressive plasminogen activation with tissue plasminogen activator (tPA) and to determine the extent of inhibition of fibrinolysis mediated by tPA with aprotinin and activated factor XIII. While the estimated % lysis and clot lysis time were significantly affected by tPA (0-300 U/ml), elastic modulus-based analyses in a more activity-specific fashion demonstrated significantly decreased onset, increased rate and increased extent of fibrinolysis. Furthermore, aprotinin was found to inhibit the onset, rate and extent of fibrinolysis in an activity-dependent fashion, whereas activated factor XIII was noted to enhance the speed of onset of clot growth and delay the onset of fibrinolysis. In summary, our results serve as the rational basis to utilize this elastic modulus-based approach to quantify the extent of fibrinolysis in clinical and laboratory settings, as well as potentially guiding antifibrinolytic therapy.

Analysis of Variance↗
PubMed2006

The effects of unfractionated heparin, low molecular weight heparin and danaparoid on the thromboelastogram (TEG): an in-vitro comparison of standard and heparinase-modified TEGs with conventional coagulation assays.

To investigate the effects of unfractionated heparin (UFH), low molecular weight heparin (LMWH) and danaparoid (DPD) added to whole blood in vitro on standard and heparinase-modified thromboelastogram (TEG) parameters compared with conventional assays of coagulation. The effects of UFH, LMWH and DPD on standard TEG parameters were compared with the prothrombin time, activated partial thromboplastin time, thrombin time and anti-activated factor X (anti-FXa) activity, at concentrations of these anticoagulants ranging from 0.025 to 1 U/ml. In the second part of the study, the effects of very low concentrations (0.005-0.05 U/ml) of UFH, LMWH and DPD on the difference between standard and heparinase-modified TEG parameters were compared with the prothrombin time, activated partial thromboplastin time, thrombin time and anti-FXa activity. Standard TEG parameters were outside the reference range at lower concentrations of UFH, LMWH and DPD than most conventional coagulation assays were able to detect. Only anti-FXa activity was more sensitive to the presence of these anticoagulants than the standard TEG alone. The lowest concentration of UFH, LMWH and DPD used in this study (0.005 U/ml) caused significant differences between the standard and heparinase-modified alpha-angles of the TEG. In addition, the difference between standard and heparinase-modified TEG parameters distinguished between low concentrations (0.005-0.05 U/ml) of UFH with greater sensitivity than anti-FXa activity, but were less sensitive to LMWH and DPD. The standard TEG is more sensitive to UFH, LMWH and DPD than most conventional coagulation tests, with the exception of anti-FXa activity. Calculation of the difference between standard and heparinase-modified TEG parameters greatly increases the sensitivity of the assay for the effects of these anticoagulants, and is more sensitive to very low quantities of UFH than anti-FXa activity.

Adult↗
PubMed2006

Resistance of porcine blood clots to lysis relates to poor activation of porcine plasminogen by tissue plasminogen activator.

In-vitro experimentation was performed on porcine and human blood to determine their comparative responsiveness to a novel fibrinolytic inhibitor and thereby assess whether the pig is a suitable animal model for subsequent in-vivo testing of this inhibitor. Thromboelastography showed the clots formed from porcine whole blood to be highly resistant to tissue plasminogen activator (t-PA)-catalyzed lysis, and this communication offers the resistance of porcine plasminogen to activation by t-PA as an explanation. Porcine blood containing 100 and 1500 IU/ml added t-PA lysed very slowly, having LY30 values of 1.9 +/- 1.4 and 2.9 +/- 1.9%, respectively. In contrast, the LY30 values for the human clots containing 100 and 1500 IU/ml t-PA were 77.1 +/- 6.3 and 93.3 +/- 1.3%, respectively. Moreover, purified porcine plasminogen was activated very slowly by added t-PA in the presence of both human and porcine fibrin. Activation of plasminogen by the endogenous activators, as measured by the euglobulin clot lysis time, was greatly prolonged for the pig (22 +/- 3 h) compared with the human (3.5 +/- 1.5 h). These results suggest caution in using the pig as an experimental model when studying the effects of various agents on fibrinolysis.

Animals↗
PubMed2006

Global assessment of the coagulation status in type 2 diabetes mellitus using rotation thromboelastography.

Clinical and epidemiologic observations have led to the concept of a procoagulant state in type 2 diabetes. This study aimed to determine the coagulation status in type 2 diabetic patients using rotation thromboelastography (ROTEM), which measures the interactive dynamic coagulation process. For this purpose, 51 (30 women, 21 men) type 2 diabetic patients (mean age, 56.1 years) and 40 age-matched, sex-matched and body-mass-index-matched healthy individuals were enrolled. Twenty-seven of the diabetic group had diabetic vascular complications. ROTEM using different activators for the intrinsic and extrinsic systems of coagulation cascade (intrinsic TEM-INTEM, extrinsic TEM-EXTEM, FIBTEM) was used to measure the coagulation time (CT), clot formation time (CFT), alpha angle (alpha) and maximum clot firmness (MCF). No significant difference was found in the prothrombin time, partial thromboplastin time, thrombin time, fibrinogen and platelet count between the two groups. INTEM-CT and INTEM-CFT and EXTEM-MCF were significantly higher in the diabetic group compared with controls (P = 0.012, P = 0.007 and P = 0.029, respectively). INTEM alpha in the diabetic group was significantly lower than the controls (P = 0.001). All other parameters, including INTEM-MCF, EXTEM-CT, EXTEM-CFT, EXTEM-alpha, FIBTEM-CT, FIBTEM-CFT, FIBTEM-MCF and FIBTEM-alpha, were similar between the two groups. Taking into account these data, we conclude that there is subtle activation of the extrinsic pathway with a concomitant decrement in the intrinsic pathway of the coagulation cascade in type 2 diabetes. The exact underlying mechanisms leading to these changes, and their consequences with regard to diabetic complications, remain to be determined.

Blood Coagulation↗
PubMed2006

Tranexamic acid does not correct the haemostatic impairment caused by hydroxyethyl starch (200 kDa/0.5) after cardiac surgery.

We investigated the effect of intravenous tranexamic acid on hydroxyethyl starch (HES)-induced clot strength impairment after cardiac surgery. Patients were randomized to receive either 1 g tranexamic acid or the same volume of 0.9% saline after administration of 15 ml/kg of 6% HES (molecular weight, 200 kDa; degree of substitution, 0.5) in the immediate postoperative period. Modified thromboelastometry (ROTEM) using different activators [intrinsic ROTEM (InTEM), extrinsic ROTEM (ExTEM), fibrinogen ROTEM (FibTEM)] was carried out to evaluate clot formation and lysis. The clot formation time was prolonged, and the maximum clot firmness (MCF) and shear elastic modulus [G = 5000 x MCF / (100-MCF), dynes/cm(2)] decreased (all activators of ROTEM) after completion of HES (P < 0.001, two-factor analysis of variance). These abnormalities in blood coagulation persisted despite tranexamic acid. Maximal lysis (FibTEM), indicative of fibrinolytic activity, was increased after HES but no effect of tranexamic acid was observed. The cumulative chest tube drainage until the first postoperative morning was not different between the groups (1008 +/- 251 and 1081 +/- 654 ml, P = 0.698, respectively). We conclude that after cardiopulmonary bypass, HES-induced impairment in clot formation and strength, or increased fibrinolytic capacity, is not reversed by the administration of tranexamic acid.

Antifibrinolytic Agents↗