Effect of epsilon-aminocaproic acid and beta-aminopropionitrile on the nutritional atheromatosis of the rabbit.
Explore the source record for details and available documents.
Aminocaproates↗
SEARCH · PubMed Health
Results for “THROMBELASTOGRAPHY”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
[Epidural analgesia in a pregnant woman with essential thrombocythaemia].
Epidural analgesia is often considered as risk of epidural haematoma in patient with essential thrombocythaemia because of the platelet disorder. In this observation, uncomplicated epidural analgesia was performed in a pregnant woman with asymptomatic essential thrombocythaemia, because the absence of bleeding symptoms was associated with normal thrombo-elastography and time of occlusion by PFA-100 suggesting normal platelet function. PFA-100 is a biological test evaluating platelet function in whole blood, which is easy and quick to perform. This case study suggests that this test might be useful in evaluating platelet function in obstetrics but must be validated before recommending its extensive use.
Adult↗
[Monitoring of hemostasis during liver transplantation: contribution of thromboelastography].
Monitoring of coagulation is mandatory during liver transplantation (LT). Standard coagulation tests may be routinely used. However, they give static information and may be inadequate in case of severe coagulation defect. Interest has been recently focused on thromboelastography (TEG) which could give more suitable and rapid information in these cases. Few studies have evaluated the clinical interest of TEG compared to conventional tests. This comparison was the aim of the present study, performed in 89 patients scheduled for LT. The anaesthetic management as well as procedure of transfusion were similar in all patients. Before unclamping, 5000 KIU.kg-1 of aprotinin were injected. Routine tests and TEG were performed at the beginning and end of both pre-anhepatic and anhepatic phases, and 5, 30, 60, and 120 min after the revascularisation of the new liver. A phase of hypocoagulability was observed after unclamping. Biological signs included an increase in activated thromboplastin time, a reduction of alpha angle and maximum amplitude on TEG with a lengthening of its r + k component. A strong correlation existed between maximum amplitude and platelets, maximum amplitude and fibrinogen, alpha and fibrinogen at each time of the surgical procedure. Euglobulin lysis time decreased significantly after clamping, whereas fibrin degradation products increased at the same time. However, typical fibrinolysis with a clot lysis index (CLI) below 55% was only observed in 15 patients. Twelve of them had a CLI value reaching 0%, associated with severe generalized oozing. Aprotinin (200,000 to 600,000 KIU) corrected these abnormalities. These results show that TEG may not be very helpful to determine whether platelets or fibrinogen are involved in the phase of hypocoagulability detected after unclamping.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Use of thromboelastography in the management of von Willebrand's disease during cardiopulmonary bypass.
Explore the source record for details and available documents.
Aged↗
Desmopressin acetate following cardiopulmonary bypass: evaluation of coagulation parameters.
Desmopressin acetate (DDAVP) has been advocated as efficacious in reducing mediastinal bleeding following cardiopulmonary bypass (CPB), and has been shown to ameliorate platelet dysfunction; however, this has not been evaluated during routine coronary artery bypass grafting (CABG). In the present study, this therapy was evaluated utilizing the thromboelastograph (TEG), a rapid, on-line means of diagnosing a coagulopathy. During elective CABG, 20 patients received either DDAVP, 0.3 microgram/kg, intravenously, following heparin reversal after CPB, or a placebo infusion, in a randomized, double-blind fashion. Hemostasis was monitored with both the TEG and conventional coagulation tests. No significant differences between the two groups were found at induction, postprotamine, post-"study infusion," or 2 hours postoperatively, with the exception of the postoperative PTT (31.1 +/- 3.2 v 36.5 +/- 5.9 seconds for DDAVP v placebo, P = 0.03). Total blood products transfused intraoperatively, and in the first 8, 16, 24, or 48 postoperative hours, were also similar between the groups. No manifestations of hypercoagulability were seen, but hypotension during the infusion was noted in four patients receiving DDAVP, and in none of the controls. It is concluded that the expense and potential complications of DDAVP therapy do not justify its routine use in CABG.
Blood Coagulation↗
Coagulation status using thromboelastography in patients receiving warfarin prophylaxis and epidural analgesia.
To determine the coagulation status of patients receiving postoperative warfarin and epidural analgesia using thromboelastography (TEG(R)).Prospective, observational, clinical study.Orthopedic postoperative division at a university hospital.52 ASA physical status II and III patients undergoing knee arthroplasty and receiving prophylactic warfarin and epidural analgesia.Patients' preoperative and postoperative coagulation status was determined by TEG(R). Daily TEG(R) parameters were obtained until the epidural catheter was removed. TEG(R) parameters include reaction time (R-time or time until the first significant levels of detectable clot formation), K-time (clot firmness), maximum amplitude (MA-clot strength), alpha angle (clot development), and coagulation index (overall coagulation). In addition, daily international normalized ratios (INRs) were obtained as per our routine practice. On the day of catheter removal reaction time was significantly increased compared with preoperative values (p < 0.0001), but it remained within normal ranges. There was no change in the coagulation index. However, INR was abnormal and significantly increased (INR = 1.48+/-0.3; p < 0.0001), compared with preoperative values, on the day when the epidural catheter was removed. When the epidural catheters are removed, overall coagulation status, as measured by TEG(R), and despite an elevated INR (mean INR <1.5), remained within normal limits in patients receiving low-dose warfarin prophylaxis.
Aged↗
Monitoring of hirudin therapy with the Thrombelastograph.
Lepirudin is a specific thrombin inhibitor that is used for anticoagulation in patients with heparin-induced thrombocytopenia who are also undergoing cardiopulmonary bypass (CPB). Monitoring of lepirudin during CPB has been carried out with activated clotting time and ecarin clotting time. Correlation is poor with the former method, whereas ecarin clotting time is not widely available. A patient is described with heparin-induced thrombocytopenia who underwent CPB, where coagulation monitoring was accomplished with the Thrombelastograph. This more widely available method may be useful in such patients.
Anticoagulants↗
Perioperative use of the Thrombelastograph in patients with inherited bleeding disorders.
There are few reports of the use of Thrombelastgraph (TEG) in patients with isolated or inherited bleeding disorders. Three surgical patients are presented with von Willebrand's disease, factor XII deficiency, and hemophilia A with dysfibrinogenemia in which the abnormalities detected by the TEG were similar to the expected coagulation abnormalities based on preoperative laboratory studies. This initial report suggests that this potential application of the TEG be further investigated.
Adenoidectomy↗
Perioperative hypercoagulability in uremic patients: a viscoelastic study.
STUDY OBJECTIVE: To examine whole blood coagulation in uremic patients presenting for surgery with the thromboelastogram and the Sonoclot analyzer. DESIGN: Prospective, observational study. SETTING: Operating rooms of a university-affiliated hospital. PATIENTS: 30 ASA physical status II and III patients with chronic renal failure, and 30 age-matched and gender-matched patients with normal renal function, presenting for elective surgery. INTERVENTIONS: Blood sampling for thromboelastograph and Sonoclot analysis immediately after anesthetic induction, prior to surgical incision. MEASUREMENTS AND MAIN RESULTS: Thromboelastographic indices of coagulation, reflecting coagulation factor function (R time), fibrinogen-platelet interaction (K time and alpha angle), and qualitative platelet function (maximum amplitude) were hypercoagulable in the uremic group compared with the control group (p < 0.05). Fibrinolysis (%) was decreased in the uremic group (p < 0.05). Fibrin formation (initial slope) and platelet function (time to peak) of the Sonoclot trace also were hypercoagulable in the uremic group (p < 0.05). CONCLUSIONS: The high incidence of arteriovenous graft and fistulae thromboses in uremic patients belies in vitro laboratory evidence of platelet dysfunction. We have demonstrated perioperative hypercoagulability in uremic patients with viscoelastic measures of whole blood coagulation. These data suggest that traditional concern for coagulopathy and platelet dysfunction in uremic patients may require re-assessment in light of this "pro-thrombotic" state.
Adult↗
Lidocaine and bupivacaine exert differential effects on whole blood coagulation.
STUDY OBJECTIVES: To compare bupivacaine to lidocaine's effects on blood clotting at two concentrations, and to characterize and determine relative effects of two equianalgesic bupivacaine and lidocaine concentrations. DESIGN: Prospective, dual-controlled, whole blood equal volume admixture thrombelastographic (TEG) study. SETTING: University of Pennsylvania Medical Center operating rooms. PATIENTS: 20 ASA physical status I and II patients' blood comprised control groups and anesthetic groups. INTERVENTIONS: Analysis of whole blood clotting used six TEG channels for untreated and saline controls and four final concentrations (1.0% lidocaine, 0.5% lidocaine, 0.25% bupivacaine, and 0.125% bupivacaine) of local anesthetics. Saline control and the local anesthetic-treated specimens underwent 8.3% hemodilution. MEASUREMENTS AND MAIN RESULTS: Blood was studied. Saline control or four anesthetic solutions (30 microliters) were added in random order two 5 TEG cuvettes. Whole blood (330 microliters) was mixed ex vivo at 37 degrees C. A sixth channel with untreated whole blood (360 microliters) acted as an undiluted control. Data for four TEG parameters [reaction time (r), angle (alpha), maximum amplitude (MA), and percent decrease in TEG amplitude from MA 30 minutes after MA acquisition (Lysis 30)] for undiluted control and saline volumetric controls were compared to each other using Student's t-test for paired observations. Lidocaine and bupivacaine groups' TEGs were compared to the paired saline control analysis of variance for repeated measures. A p-value less than 0.05 was considered significant. There was no difference between whole blood and saline control TEGs. All local anesthetics produced significant hypocoagulable changes from control. Angle alpha and MA were significantly decreased in all local anesthetic groups. Ther time was prolonged only in the high lidocaine-treated blood. Lysis was a feature of the low lidocaine and bupivacaine solutions. Equianalgesic lidocaine produced more profound hypocoagulable effects than did bupivacaine. CONCLUSIONS: Lidocaine and bupivacaine both significantly impaired TEG coagulation in a concentration-dependent manner. Lidocaine was significantly more hypocoagulable than bupivacaine at two similarly analgesic concentrations.
Analysis of Variance↗
The timing for the use of heparinase and tromboelastography to prevent excessive bleeding coronary artery bypass graft surgery.
Explore the source record for details and available documents.
Cardiopulmonary Bypass↗
Bedside coagulation monitoring.
Explore the source record for details and available documents.
Blood Coagulation↗
Changes in transfusion therapy and reexploration rate after institution of a blood management program in cardiac surgical patients.
A retrospective study was performed to determine the impact of a coagulation and transfusion management program on blood utilization in 1,079 sequential patients for myocardial revascularization and open ventricle or combined procedures. Four hundred and eighty-eight patients (group 1) before, and 591 patients (group 2) after institution of thromboelastography (TEG)-guided coagulation were studied and compared for transfusion requirements, donor exposure, and the incidence of reoperation for hemorrhage. Group 2 patients had a significantly lower incidence of overall transfusion (78.5% v 86.3%) during hospitalization and in total transfusion in the operating room (57.9% v 66.4%). The incidence of each transfusion subtype was also significantly lower in group 2 patients. Actual total median donor exposure was 8 in group 1 patients and 6 exposures in group 2 patients. Mediastinal reexploration for hemorrhage was 5.7% before institution of TEG-based coagulation monitoring and 1.5% in TEG-monitored patients. Use of TEG monitoring before reexploration has decreased the cost and potential risk for patients undergoing CABG surgery.
Blood Coagulation↗
Platelet concentrate effects on thromboelastography.
OBJECTIVE: This study evaluated platelet effects on thromboelastography to determine how morphologically abnormal platelets affected native whole blood analysis. DESIGN: Prospective, controlled comparison. SETTING: Tertiary care university hospital. PARTICIPANTS: Volunteer cardiac surgery patients. INTERVENTIONS: Fresh platelets were obtained from volunteers and were either treated normally or cryodisrupted with liquid nitrogen. Fresh platelets, liquid nitrogen-treated platelets, or an equivalent quantity of the patient's blood were added to whole blood samples obtained from cardiac surgery patients before heparinization. Thromboelastographic parameters sensitive to platelet effects were measured in each of the three groups. MEASUREMENTS AND MAIN RESULTS: Maximum amplitude and alpha-angle significantly increased in the two groups receiving added platelets. There were no differences between the fresh platelet and the liquid nitrogen-treated platelet groups (Student's paired t-test). The R-time decreased significantly in both platelet-treated groups compared with the group that did not receive additional platelets. CONCLUSIONS: Viscoelastic changes in whole blood coagulation after the addition of platelet concentrates are not dependent on morphologically intact or functionally normal platelets. This in vitro study predicts that transfusion of poorly preserved platelet concentrates as well as fresh platelets would increase clot strength on thromboelastography if the recipient's blood were tested immediately after administration.
Blood Coagulation↗
Heparin detection by the activated coagulation time: a comparison of the sensitivity of coagulation tests and heparin assays.
OBJECTIVE: Laboratory and point-of-care coagulation tests are frequently obtained to determine the presence of heparin after surgical procedures. The objective of this study was (1) to compare the sensitivity of the activated coagulation time (ACT), activated partial thromboplastin time (aPTT), protamine titration (Hepcon; HMS Medtronic, Hemotec, Englewood, CO), and thromboelastography (TEG) with heparin anticoagulation and (2) to determine how frequently residual heparin is present in the 24-hour period after heparin neutralization in cardiopulmonary bypass (CPB) patients. DESIGN: A prospective study. SETTING: A tertiary care university teaching center that performs more than 15,000 surgical procedures per year. PARTICIPANTS: Vascular surgical (n = 17) and CPB (n = 29). INTERVENTIONS: In vascular surgical patients, coagulation tests (ACT, protamine titration [Hepcon], and TEG) were obtained before and 90 minutes after heparin (50 to 60 U/kg IV) and compared with heparin concentration determined by factor Xa inhibition assay. In cardiac surgical patients, ACT and heparin concentrations were measured after anesthesia induction, during CPB, after protamine neutralization, and 3 as well as 6 hours after CPB. In addition to heparin concentrations and ACT measures, platelet counts, fibrinogen levels, and bleeding times were determined before and 3 and 24 hours after CPB. MEASUREMENTS AND MAIN RESULTS: Ninety minutes after heparin, significant heparin concentrations were present in all vascular surgical patients, but ACT was elevated in only 4 of 17 patients. Protamine titration (Hepcon) correlated with the factor Xa inhibitory assay for heparin (r2 = 0.76). All 17 patients had an abnormal TEG (mean "R" time = 81 +/- 39 minutes) and a marked elevation of aPTT (135 +/- 35 sec [normal 22 to 33 seconds]) 90 minutes after heparin. In CPB patients, ACT did not correlate with heparin assays. After protamine neutralization of heparin in CPB patients, ACT returned to baseline despite the presence of heparin in 3 of 29 patients (0.22, 0.18, and 0.33 U/mL). CONCLUSIONS: ACT was less sensitive to residual heparin anticoagulation than aPTT, TEG, and whole blood heparin assay. The whole blood heparin assay (Hepcon) provided sensitive and specific data about the presence of residual heparin. Despite the limitation of ACT in detecting heparin, the investigators found that residual heparin was not common in the period after uncomplicated CPB.
Aged↗
Thromboelastography with heparinase in orthotopic liver transplantation.
OBJECTIVE: To investigate the role of heparin in the postreperfusion coagulopathy during liver transplantation with heparinase-guided thromboelastography. DESIGN: A prospective, interventional study. SETTING: A university-affiliated hospital. PARTICIPANTS: Twenty-six patients undergoing orthotopic liver transplantation (OLT). INTERVENTIONS: Blood drawn at five intervals for thromboelastography assessment with native (12 patients) or celite blood (14 patients) compared with simultaneous thromboelastography traces with added heparinase. MAIN RESULTS: In the native samples, the prolonged R (reaction) and K (coagulation) time and decreased alpha angle were corrected in heparinase thromboelastograph traces immediately before reperfusion and 10 minutes postreperfusion. In the celite-accelerated samples, the heparinase traces showed correction of the R and K times and alpha angle only at the 10-minute postreperfusion stage. In seven patients who had thromboelastography performed after protamine administration, there were no differences between celite and heparinase-celite traces. CONCLUSIONS: Heparinase-treated thromboelastography offered compelling evidence for the presence of heparin-like activity after liver graft reperfusion. The objective evidence provided by this modification of thromboelastography-guided protamine administration and was useful in identifying one of the many potential causes of postreperfusion bleeding in patients undergoing OLT.
Blood Coagulation↗
Fibrinolysis in pediatric patients undergoing cardiopulmonary bypass.
OBJECTIVE: Thromboelastographic evaluation of the influence of fibrinolysis on blood loss and blood product transfusions in children during cardiac surgery. DESIGN: Prospective study. SETTING: University-affiliated, pediatric medical center. PARTICIPANTS: Two hundred seventy-eight consecutive children undergoing cardiac surgery. INTERVENTIONS: Blood sampling for coagulation tests, including native and protamine-modified thromboelastography. MEASUREMENTS AND MAIN RESULTS: Blood coagulation tests were measured before, during, and after cardiopulmonary bypass (CPB). Demographic data, perioperative blood loss, and blood product transfusions were prospectively recorded. Fibrinolysis was defined as thromboelastography of A30/MA less than 0.85 (MA, maximum amplitude; A30, amplitude 30 minutes after MA) and was noted in 3% of children pre-CPB, 16% during CPB, and 3% post-CPB. Fibrinolysis before CPB was associated with poor cardiac output. Fibrinolysis during CPB occurred in young children (aged 350 +/- 836 days) undergoing complex surgery with prolonged CPB (119 +/- 48.8 minutes) and deep hypothermia (25.6 degrees C +/- 4.7 degrees C). These patients received blood products after CPB and were not fibrinolytic after transfusion. They incurred similar blood loss (in mL/kg) and received similar volumes of blood products (mL/kg) as age-matched and surgery-matched patients without fibrinolysis. CONCLUSION: A group of children at risk for fibrinolysis during CPB was identified. However, fibrinolysis during CPB did not influence blood loss or the total volume of blood products transfused.
Blood Loss, Surgical↗
An alternate method for calibrating the thromboelastograph.
OBJECTIVE: This study evaluated various substances that could be used to calibrate the Thrombelastograph. DESIGN: Prospective, controlled comparison. SETTING: Operating room laboratory at a tertiary care university hospital. PARTICIPANTS: None. INTERVENTIONS: Six substances commonly available in the operating room setting (ointments, creams, and gels) were analyzed by thromboelastography for 3 minutes. Sixty measurements were made for each substance. MEASUREMENTS AND MAIN RESULTS: Thromboelastographic analysis of the ointments and cream preparations had an amplitude variability that exceeded 10 mm within the 3-minute recording period. The conductive gel had the most reproducible thromboelastography tracing with a mean amplitude of 62.5 +/- 1.1 mm (analysis of variance, p < 0.0005). There was a significant correlation between the reported viscosity of the three gels and the deflection amplitude (linear regression, R2 = 0.97; p < 0.0001). CONCLUSION: Conductive gel is a useful substance for quickly checking the functional status of the Thrombelastograph at an operational stage. Calibration of the Thrombelastograph using a gel of known viscosity is clinically relevant and may be more practical than testing with thromboelastographic-defined normal and abnormal blood analogs.
Calibration↗