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At least 685 records · Page 38Linked to original sources
PubMed2002

A prospective, randomized comparison of thromboelastographic coagulation profile in patients receiving lactated Ringer's solution, 6% hetastarch in a balanced-saline vehicle, or 6% hetastarch in saline during major surgery.

OBJECTIVES: To compare the effects of lactated Ringer's solution (LR), 6% hetastarch in a balanced-saline vehicle (HS-BS), and 6% hetastarch in normal saline (HS-NS) on coagulation using thromboelastography. DESIGN: Prospective, randomized double-blinded evaluation of previously published clinical trial. SETTING: Tertiary-care medical center. PARTICIPANTS: Patients undergoing elective noncardiac surgery with an anticipated blood loss >500 mL. A total of 90 patients were enrolled with 30 patients in each group. INTERVENTIONS: Patients received a standardized anesthetic. LR, HS-BS, and HS-NS were administered intraoperatively based on a fluid administration algorithm. Hemodynamic targets included maintenance of arterial blood pressure, heart rate, and urine output within a predefined range. MEASUREMENTS AND MAIN RESULTS: Thromboelastography variables for r time, k time, maximum amplitude, and alpha angle (mean +/- SD) were recorded at induction of anesthesia, at the end of surgery, and 24 hours postoperatively. Patients in the LR group showed a state of hypercoagulation at the end of surgery with reductions (p < 0.005) in r time (-3.8 +/- 6.7 mm) and k time (-1.7 +/- 2.5 mm). This state of hypercoagulation continued into the postoperative period. Patients in the HS-NS group showed a state of hypocoagulation with increases (p < 0.05) in r time (+6.2 +/- 8.5 mm) and k time (+1.7 +/- 3.9 mm) and a reduction in maximum amplitude (-8.0 +/- 9.8 mm) at the end of surgery. This state of hypocoagulation was reduced in the postoperative period. Patients in the HS-BS group showed no significant changes in coagulation status at end of surgery, with the smallest changes in r time (-0.3 +/- 4.1 mm), k time (+0.1 +/- 3.1 mm), maximum amplitude (-5.4 +/- 12.3 mm), and alpha angle (0.3 +/- 12.5 degrees ). CONCLUSION: LR-treated patients exhibited a hypercoagulative profile that persisted into the postoperative period. HS-BS administration was associated with a lesser change in the coagulation profile compared with HS-NS, which was associated with a hypocoagulative state.

Aged↗
PubMed2002

Prediction of excessive bleeding after coronary artery bypass graft surgery: the influence of timing and heparinase on thromboelastography.

OBJECTIVE: To compare the ability of thromboelastography, when done at either 10 or 60 minutes after protamine reversal of heparin, to predict excessive bleeding after coronary artery bypass graft (CABG) surgery and to investigate, with the use of heparinase, whether heparin contamination was responsible for the difference, if any. DESIGN: Prospective study. SETTING: University hospital, single institution. PARTICIPANTS: Patients undergoing elective CABG surgery (n = 40). INTERVENTIONS: Blood samples for thromboelastography and routine coagulation tests were collected before induction of anesthesia and at 10 and 60 minutes after protamine reversal of heparin. Blood loss and blood product use were recorded postoperatively. MEASUREMENTS AND MAIN RESULTS: Of 40 patients undergoing elective CABG surgery, 10 fulfilled the criteria for excessive postoperative bleeding. The sensitivity of thromboelastography to identify patients who bled was better at 60 minutes than at 10 minutes after protamine reversal of heparin (100% v 70%). There was greater specificity (83% v 40% at 10 minutes; 73% v 20% at 60 minutes) and positive predictive value (58% v 28% at 10 minutes; 55% v 29% at 60 minutes) when heparinase was added. At both times, thromboelastography showed only moderate correlation with total blood loss and the use of fresh frozen plasma or platelets or both. Conventional coagulation tests did not predict excessive postoperative bleeding. CONCLUSION: This study suggests that timing and the use of heparinase influence the predictive ability of thromboelastography, but its usefulness as a sole predictor of post-CABG surgery bleeding is limited.

Aged↗
PubMed2002

Differences in arterial and venous thromboelastography parameters: potential roles of shear stress and oxygen content.

OBJECTIVE: To investigate potential mechanisms for the differences in thromboelastography variables observed between arterial blood samples and venous blood samples. DESIGN: Prospective cohort study. SETTING: University hospital. PARTICIPANTS: Patients undergoing cardiac surgery (n = 33). INTERVENTIONS: After the withdrawal of 10 mL of discarded blood (>3 deadspace volumes), 3 blood samples were withdrawn simultaneously from the central venous port of the pulmonary artery catheter (CVP), the radial arterial catheter (ART), and the side port of the 9F sheath introducer (SI). MEASUREMENTS AND MAIN RESULTS: Thromboelastography was done simultaneously on each sample. All thromboelastography analyses were performed with 1% celite and heparinase according to the manufacturer's guidelines. A total of 80 ART, SI, and CVP comparisons were obtained. Mean hematocrit values were not different between sampling sites (27 +/- 4 v 27 +/- 4 v 27 +/- 3). Thromboelastography R time values (mean +/- SD) were CVP, 8 +/- 3; ART, 10 +/- 3; and SI, 13 +/- 5 (p = 0.004). Thromboelastography maximal amplitude (MA) values (mean +/- SD) were CVP, 60.4 +/- 11.7; ART, 56.2 +/- 11.4; and SI, 50.5 +/- 13.2 (p = 0.008). Calculated maximal shear stresses were CVP, 48 dyne/cm(2); ART, 36 dyne/cm(2); and SI, 0.3 dyne/cm(2). Blood samples obtained from the CVP (highest shear stress) resulted in faster (shorter R) and stronger (larger MA) coagulation compared with the arterial site (intermediate shear stress) and sheath introducer (lowest shear stress). CONCLUSION: These data show that differences exist in thromboelastography values between arterial and venous blood samples and, more importantly, show that the differences observed are not related to differences in oxygen content. These differences seem to be related to differences in catheter lumen diameter and, presumably, shear forces.

Adult↗
PubMed2000

Effects of DETANONOate, a nitric oxide donor, on hemostasis in rabbits: an in vitro and in vivo thrombelastographic analysis.

PURPOSE: The purpose of this study was to determine if whole blood thrombelastographic variables (reaction time, K, alpha, and maximum amplitude) would be adversely effected by exposure to the nitric oxide (NO) donor, DETANONOate, in vitro or after alveolar instillation in vivo. MATERIALS AND METHODS: Conscious rabbits (n = 10) had blood sampled from ear arteries anticoagulated with sodium citrate. The blood was then incubated with 0, 1, 5, 10, or 20 mmol/L DETANONOate for 30 minutes. Arterial blood from anesthetized rabbits (n = 4) was obtained and anticoagulated before and 60 minutes after 1 mmol/L DETANONOate (2 mL/kg) was instilled into the right lung. After incubation, all samples were placed in a thrombelastograph and recalcified, with thrombelastographic variables measured for 45 minutes. RESULTS: In vitro, 10 mmol/L DETANONOate significantly (P < .05) increased reaction time, K, and decreased alpha compared with values observed after incubation with 0, 1, and 5 mmol/L DETANONOate. Twenty mmol/L DETANONOate significantly (P < .05) increased reaction time, K, and decreased alpha and maximum amplitude values compared with all other concentrations. In vivo, DETANONOate administration did not significantly affect thrombelastographic variables. CONCLUSION: DETANONOate significantly decreased hemostatic function in vitro in a dose-dependent fashion but did not significantly affect hemostatic function in vivo.

Animals↗
PubMed1975

[Influence of cytostatic combination therapy with vincristine sulphate and iphosphamide on blood coagulation].

Disorders of blood coagulation were investigated before and during a cytostatic combination therapy with vincristine sulphate and iphosphamide (Asta Z 4942) in 12 patients with malignant tumours or haemoblastoses. Thromboplastin time, partial thromboplastin time, thrombin time, heat-dependent fibrin, clot retraction, and clotting factors II, V, VIII, IX, X, and the platelet count were determined. A change in the plasmatic coagulation system attributable to the combination therapy could not be demonstrated in any patient. The influence of the cytostatic combination on the platelet-dependent haemostasis was small; a decrease in platelet count could be observed in only one patient, in whom an additional causative damage to thrombopoiesis due to the underlying disease could be assumed. Regardless of the cytostatic therapy there were indications of a hypercoagulability in 10 patients. This explains the increased susceptibility of such patients for thromboses or consumption coagulopathy.

Adult↗
PubMed1975

[Coagulation tests in von Willebrand's disease(author's transl)].

The diagnosis of von Willebrand's disease can be made by a selected series of easily performed clotting tests. A STudy of 36 patients with the disease (all but one with a mild form) revealed a significantly increased reaction time in the thrombelastogram from 210 plus or minus 33 percent to 270 plus or minus 69 percent (P less than 0.001), and of the partial thromboplastin time from 43 plus or minus 3s to 54 plus or minus 9s (P less than 0.001 than 0.001). Factor VIII activity was corresponding significantly reduced from normal (127 plus or minus 51 percent) to 51 plus or minus 12 percent (P less than 0.001). Other plasma factors and platelet counts were within normal limits. A platelet defect was indicated by an abnormal change in the speed of clot formation (k-time) from 162 plus or minus 39 percent to 341 plus or minus 121 percent (P less than 0.001), maximal thrombelasticity from 121 plus or minus 16 percent to 75 plus or minus 22 percent (P less than 0.001), and marked reduction in platelet-factor 3 liberation from 122 plus or minus 59 percent to 23 plus or minus 16 percent (P less than 0.001). An increase in bleeding time, from 162 plus or minus 41s to 204 plus or minus 128s (P less than 0.05), was not always present. Recently introduced immunological methods for determining factor VIII and factor VIII-associated protein, as well as special platelet-function tests, give further information on the pathogenesis of the bleeding disease, but their complexity restricts them to special laboratories.

Blood Coagulation Factors↗
PubMed1975

[Thrombotic occlusion of an arteriovenous Cimino shunt in acute pancreatitis (author's transl)].

An arteriovenous (Cimino) shunt in both right and left forearms clotted during an episode of acute pancreatitis in two patients on chronic haemodialysis. Systemic hypercoagulability (circulating fibrin monomers, shortening of r and k time in the thrombelastogram and shortening of the PTT-time) occurred in association with inhibition of fibrinolysis (prolongation of euglobulin lysis time). Localized thrombosis at the shunt is thought to be due to superimpostition of systemic hyper-coagulability on a local increase in platelet adhesiveness.

Acute Disease↗
PubMed1975

[Measurement of electric impedance as a screening method for diagnosing haemorrhagic diatheses (author's transl)].

Changes in electrical impedance during blood clotting have been previously described. Personal measurements on blood of 18 healthy donors and 29 patients with various disorders of clotting gave reproducible results with this method. There was a marked difference between normal subjects and those with bleeding diatheses regardless of type. There was good correlation between impedance changes and the thrombelastogram, the former being more sensitive in diagnosing haemorrhagic disorders. Further studies are required to evaluate its place as a screening method in these conditions.

Blood Coagulation Disorders↗