Maximum Clot Amplitude Research Articles

Hemostatic Effects of Exercise-related Hypoglycemia in Male Persons With Type 1 Diabetes.

People with type 1 diabetes (T1D) are at increased risk of thrombosis compared to the general population; however, the underlying mechanisms remain unclear. Hypoglycemia induced at rest can induce coagulation activation, but little is known about the hemostatic effects of exercise-related hypoglycemia in people with T1D. We compared hemostatic profiles of individuals with T1D with healthy controls and explored hemostatic effects of hypoglycemia, induced with or without exercise, in participants with T1D. Thrombelastography was used for a baseline hemostatic comparison between fifteen men with T1D and matched healthy controls. In addition, the participants with T1D underwent two euglycemic-hypoglycemic clamp days in a randomized, crossover fashion. Hypoglycemia was induced with the participants at rest (Hypo-rest) or during exercise (Hypo-exercise). Thrombelastography provides data on the rate of coagulation activation (R-time), the rate of clot formation (K-time, α-Angle), the maximum clot amplitude (MA), the functional fibrinogen contribution to the clot strength (MA-FF) and the fibrinolysis (LY-30). The T1D group exhibited a faster rate of coagulation activation (shorter R-time) and a faster clot formation (greater α-Angle) compared with the controls. During the clamp experiments, Hypo-exercise induced an increased clot strength (MA) with a mean difference from baseline of 2.77 mm (95% CI, 2.04-3.51) accompanied with a decreased fibrinolysis (LY-30) of -0.45 percentage point (-0.60 to -0.29). Hypo-rest resulted in increased functional fibrinogen (MA-FF) of 0.74 mm (0.13-1.36) along with an increased fibrinolysis (LY-30) of 0.54 percentage point (0.11-0.98). Individuals with T1D exhibit a hypercoagulable hemostatic profile compared with healthy controls and exercise-related hypoglycemia may increase the susceptibility to thrombosis via both procoagulant and antifibrinolytic effects.

Impact of Factor Xa Inhibition on Coagulation, Platelet Reactivity, and Thrombosis in Patients with Peripheral Artery Disease

The role of thrombin in vascular pathology is a focus of investigation. The incorporation of direct Factor Xa inhibition into practice patterns is based on its theoretical dual-pathway attenuation of both thrombin generation and platelet aggregation. However, quantification of the effect of direct anti-Xa medications on platelet function is not established. Thromboelastography with platelet mapping (TEG-PM) leverages dual-pathway metrics to provide comprehensive coagulation profiles. We evaluated the effects of direct oral anticoagulants (DOACs) on coagulation and platelet function profiles and correlate these data with postoperative major adverse limb events (MALEs) in patients with PAD. We conducted a prospective study of patients undergoing lower extremity revascularization with serial perioperative TEG-PM analysis. Patients on DOACs were compared to those not on DOACs, and stratified by concurrent mono-antiplatelet or dual-antiplatelet regimens (MAPT/DAPT). Postoperative MALE was recorded and difference in antithrombotic regimens and TEG-PM analysis compared between groups. Four hundred seventy-one samples from 141 patients were analyzed. Twenty-nine point five percent were reflective of circulating DOAC therapy. Compared to MAPT alone, patients on DOAC+MAPT exhibited longer time to clot formation (R-time) [7.4 (±2.4) vs. 6.7 (±2.7); P<0.02], but less platelet inhibition. Patients on DAPT exhibited greater platelet inhibition compared to either group [23.7 (±26.9) vs. 31.0 (±28.3) vs. 42.2 (±31.2); P<0.01]. Patients who experienced MALE were more likely to be on DOAC therapy [43.8% vs. 22.0% P=0.02]. Thromboelastography with platelet mapping analysis from patients who experienced MALE also demonstrated longer R-time [8.6 (±3.9 vs. 7.3 (±3.0); P=0.05] and increased maximum clot amplitude (MA) [66.7 (±4.2) vs. 61.8 (±8.2); P=0.001]. Direct oral anticoagulant therapy resulted in a prolonged R-time but had no impact on platelet inhibition. Patients who experienced MALE were more often on DOACs and demonstrated an increased R-time, but also showed greater platelet reactivity evident by increased MA, suggesting DOACs may not be effective at protecting against MALE. Further research comparing DOAC therapy to a DAPT approach may add clarity to emerging multimodal antithrombotic recommendations.

Utilization of Thromboelastography with Platelet Mapping to Predict Infection and Poor Wound Healing in Postoperative Vascular Patients

Postoperative infection and wound dehiscence rates are higher than expected in peripheral artery disease and contribute significantly to limb loss and mortality. Microvascular pathology characterized by microthrombi and increased platelet aggregation have been cited as contributing factors to poor wound healing and infection. The emergence of viscoelastic assays, such as thromboelastography with platelet mapping (TEG-PM), have been utilized to identify prothrombotic states and may provide insight into a patient's microvascular coagulation profile. This prospective, observational study aimed to determine if TEG-PM could predict poor wound healing or infection following lower extremity revascularization. All patients undergoing revascularization between December 2020 and January 2022 were prospectively included and followed for wound complications or non-surgical site infections of the index limb. TEG-PM metrics at the first postoperative follow-up in the nonevent group was compared to the TEG-PM sample preceding the diagnosis of infection/dehiscence in the event group. Cox proportional hazards (PH) regression was used to model the predictive value of viscoelastic parameters. Cut-point analysis to determine high-risk groups was determined by performing receiver operating characteristic curve analysis. Of the 102 patients, 18.6% experienced infection/dehiscence. The TEG-PM sample analyzed in the event group was, on average, 19.5 days prior to the diagnosis of an event. The event group had significantly higher maximum clot amplitude (MA) (47.3 mm ± 16.0 vs. 30.6 mm ± 15.3, P < 0.01), higher platelet aggregation (71.3% ± 27.7 vs. 31.2% ± 24.0, P < 0.01), and lower platelet inhibition (28.7% ± 27.7 vs. 68.7% ± 24.1, P < 0.01). Cox PH analysis identified platelet aggregation as an independent and consistent predictor of infection (hazard ratio = 1.04, 95% confidence interval 1.03-1.06, P < 0.01). An optimal cut-point of > 33.2 mm MA, > 46.6% platelet aggregation, or < 55.8% platelet inhibition identifies those with infection/dehiscence with 79.0-89.5% sensitivity. These are the first data to provide a quantitative link between prothrombotic viscoelastic coagulation profiles with the development of infection/dehiscence. Based on the cut-points of > 33.2 mm MA, > 46.6% platelet aggregation, or < 55.8% platelet inhibition, we recommend consideration of an enhanced antimicrobial or antithrombotic approach for these high risk groups.

COVID-19 patient plasma demonstrates resistance to tPA-induced fibrinolysis as measured by thromboelastography.

Patients critically ill with COVID-19 are at risk for thrombotic events despite prophylactic anticoagulation. Impaired fibrinolysis has been proposed as an underlying mechanism. Our objective was to determine if fibrinolysis stimulated by tissue plasminogen activator (tPA) differed between COVID patients and controls. Plasma from 14 COVID patients on prophylactic heparin therapy was obtained and compared with heparinized plasma from 14 different healthy donors to act as controls. Kaolin activated thromboelastography with heparinase was utilized to obtain baseline measurements and then repeated with the addition of 4 nM tPA. Baseline fibrinogen levels were higher in COVID plasma as measured by maximum clot amplitude (43.6 ± 6.9 mm vs. 23.2 ± 5.5 mm, p < 0.0001) and Clauss assay (595 ± 135 mg/dL vs. 278 ± 44 mg/dL, p < 0.0001). With the addition of tPA, fibrinolysis at 30 min after MA (LY30%) was lower (37.9 ± 16.5% vs. 58.9 ± 18.3%, p = 0.0035) and time to 50% lysis was longer (48.8 ± 16.3 vs. 30.5 ± 15.4 min, p = 0.0053) in the COVID-19 samples. Clotting times and rate of fibrin polymerization (‘R’ or ‘α’ parameters) were largely the same in both groups. Clot from COVID patients contains a higher fibrin content compared to standard controls and shows resistance to fibrinolysis induced by tPA. These findings suggest the clinical efficacy of thrombolytics may be reduced in COVID-19 patients.

Thromboelastography for the Orthopaedic Surgeon.

Evaluation of coagulation is vital in the care of the orthopaedic patients, particularly in the subspecialties of trauma, spine, arthroplasty, and revision surgery resulting from blood loss and coagulopathies. Although conventional tests (prothrombin time/international normalized ratio, activated partial thromboplastin time, platelet count, and fibrinogen) are most commonly used, others like thromboelastography (TEG) are also available to the orthopaedic surgeons. TEG is a blood test developed in the 1950s, which provides a snapshot of a patient's coagulation profile by evaluating clot formation and lysis. Recently, TEG has been used to assess traumatic coagulopathy. The coagulation parameters measured by the TEG are reaction time (R-time), time to reach a certain clot strength (K-value), speed of fibrin build up (α-angle), maximum clot amplitude, and percentage decrease of clot in 30 minutes (LY30). Using these values, traumatologists have developed a better, faster, and more accurate overview of a patient's resuscitation and more successfully direct blood product use. However, many orthopaedic surgeons-despite performing surgical procedures that risk notable blood loss and postoperative clotting complications-are unaware of the existence of the TEG blood test and the critical information it provides. Increasing awareness of the TEG among orthopaedic surgeons could have a notable effect on numerous aspects of musculoskeletal care.

Detection of individual responses to clopidogrel: Validation of a novel, rapid analysis using thrombelastography 6s.

There is potential value in testing individual response to P2Y12 inhibitors to predict ischemic and bleeding risk in patients undergoing percutaneous coronary intervention. The aims of this study were: (1) to validate the ability of a novel point of care (POC) assay, thrombelastography (TEG) 6s, to detect changes in adenosine diphosphate (ADP)-induced whole blood clotting in volunteers and patients given clopidogrel using TEG 5000 as a reference and (2) to compare a novel, rapid parameter, area under the curve at 15minutes (AUC15), with the traditional maximum clot amplitude (MA) in TEG 6s. A total of 25 participants were included in whom ADP-induced clotting was measured at 4 time points: (1) 12 healthy volunteers given 600mg of clopidogrel; (2) 12 patients with ACS given 600mg of clopidogrel; (3) 1 healthy volunteer given 600mg of clopidogrel on 5 separate occasions. All samples were tested using conventional TEG 5000 and the new POC TEG 6S, and a new parameter called AUC15 was compared with MA in TEG 6s. (1) TEG 5000 and TEG 6s both detected changes in ADP-induced platelet activation. Bland-Altman analysis demonstrated a good level of agreement between them. (2) For TEG 6S, correlation between MA and the novel AUC15 was strong for both thrombin and ADP channels (R2 =0.867, R=.936, P<.001), and the AUC15 result was available on average 13.3minutes earlier. Thrombelastography 6s is a rapid, easy to use and accurate test of ADP-induced clotting using TEG 5000 as a reference. A novel parameter, AUC15, is a viable, time-saving option for this test and has potential value in personalized P2Y12 inhibitor therapy.

Fiber-based optic sensor for detecting human blood clot: present and future revival

Sustaining human’s life-frame away from being impeded by the clot - ghost term, we attempt to approach a mobile fiber-based optical sensor (f-s) for detecting blood clot in a blood vessel (intra-arteries/veins). Blood vessels are the part of the circulatory system that transport blood throughout the human body, thus their significance of being protected arise to the monograph focus. MRI (magnetic resonance imaging), X-rays and other medical instruments are diagnostic immobility techniques with a slackest interval. The corer causation of fiber-based optical sensor is to detect a clump of blood in the bloodstream by providing a prompt mobile diagnostic intervals preserving last-minutes-breath of human’s life. The detector (f-s) has been etched by diluting sulphuric acid ~10% at certain zone to sensate its function. The in-vitro monograph peaks its maximal monitoring when the sensor is attached to Raman Spectroscopy (RS) setup. RS quantifies the relative intensities of fibrinogen bond, which is the first type of blood coagulation elements of blood plasma. Blood coagulation parameters are the major concern of the monograph investigation, such as total haemoglobin (tHb), clotting reaction time (t), clot progression time (t2), maximum clot amplitude (ma) and mean refractive index (r). A blood sample will be drawn from the patient and after centrifugation to separate blood plasma from its constituents, then an immediate sloshing of blood plasma in the (f-s) packet which has its plug-in to RS. Estimating the quantitative analysis of blood sample concentration, RS will determine the presence of coagulation in terms of intensity and medical procedures will dominate the treatment process. Thus, the suggestive monograph provides a definite instrument for investigating blood coagulation intra-arteries/veins promptly.

Assessment of rotational thromboelastometry for the prediction of red blood cell requirements in orthotopic liver transplantation.

In liver transplantation most studies were designed to predict massive transfusion rather than whether or not transfusion is required. We hypothesized that (presurgery) data from thromboelastometry may predict perioperative blood requirements. A post-hoc analysis of data from a controlled trial was performed with the primary end point of predicting zero red blood cells. Of the 92 patients studied, 6 were excluded because of incomplete EXTEM and/or FIBTEM data. The multivariate models included preoperative variables with a P value <0.10 in the univariate model: age, MELD score, hemoglobin, plasma fibrinogen, platelet count, activated partial thromboplastin time, INR, EXTEM maximum clot amplitude after 10 minutes, EXTEM an FIBTEM maximum clot firmness, plasma creatinine, and donor data. Blood was transfused to 58% of patients during the surgical procedure and to 34% in the first 24 hours postoperatively. The final model was selected using a backward approach, and fractional polynomials were explored to assess model improvement for the prediction. Hemoglobin was a strong predictor: each 1 g/dL of hemoglobin increase reduced the risk of blood transfusion by 52%. An EXTEM maximum amplitude at 10 min was also a predictor of Red Blood requirement, showing a 64% risk reduction for values between the first quartile (35 mm) and the second quartile (41 mm) but no further improvement for the third and fourth quartiles and resulting in a prediction (ROC AUC of 0.815 [0.771-0.859]). Presurgical EXTEM maximum amplitude at 10 min <35 mm is highly predictive of red blood administration during liver transplantation.

Abstract WP287: Deterioration in Recombinant Tissue Plasminogen Activator After Repeated Freezing and Thawing Cycles for Thromboelastography

Background and Purpose: Thromboelastography (TEG) is often used to measure coagulation dynamics in the setting of acute ischemic stroke and thrombolytic therapy. The stability of thrombolytics has not been investigated in TEG. We conducted an experimental series to test the effects of recombinant tissue plasminogen activator (rtPA) on fibrinolysis in normal blood samples using TEG. Methods: Freeze dried rtPA powder was reconstituted in normal saline containing 0.2% bovine serum albumin (100 mg/24 mL), divided into 1 mL aliquots, and diluted to enable using a relatively large volume for complete mixing with blood samples. Aliquots and dilutions were frozen at -20°C. The same rtPA dilution was thawed to ambient temperature before each use and refrozen until the next use over 4 testing days. Blood was drawn into 3.2% sodium citrated collection tubes. rtPA (100 μL) was added to 1 mL whole blood to achieve a 636 ng/mL rtPA TEG sample concentration. Control-whole blood and rtPA-whole blood TEG was performed for 3 h on 4 healthy human blood samples. Maximum clot amplitude (mm) and absolute clot strength (dynes/cm 2 ) were measured. Data (mean±SD) were analyzed by t-tests and significance inferred at p &lt;0.05. Results: Clot amplitude increased with thawing and refreezing (28±3, p=0.004; 35±2 p=0.01; 50±3, p=0.02; and 55±3, p=0.30; for testing cycles 1, 2, 3 and 4, respectively) compared to untreated samples (63±4). Clot strength also increased over the 4 cycles (2±0.3, p=0.007; 3±0.2, p=0.02; 5±05, p=0.01 and 6±0.7, p=0.30) compared to untreated (9±1.4). Lysis initiation time was gradually longer over the 4 tests (red arrows, Figure 1) suggesting delayed fibrinolysis. Conclusions: One repeatedly thawed and refrozen rtPA stock showed a delay in fibrinolysis in healthy human blood, suggesting a loss of potency. Thus, rtPA should be aliquoted for 1-time use for experiments using TEG. Further investigation into rtPA potency deterioration with storage after reconstitution is warranted.

Nitrite Regulation Of Platelet Reactivity Under Physiological Conditions

Nitric oxide (NO) is generated by serial reduction pathway of nitrate and nitrite or by activity of endogenous nitric oxide synthase (NOS), and modulates platelet function and hemostasis. We have shown by aggregometry and flow cytometric analysis of P-selectin that nitrite in the presence of erythrocytes inhibits platelet aggregation and activation after its reduction to NO at low oxygen tension [PLoS One. 2012; 7: e30380. 10.1371/journal.pone.0030380]. We then investigated how nitrite may affect overall clotting processes by regulating platelet function using thrombelastography (TEG), a method used to assess platelet function, fibrin clot formation, and fibrinolysis in blood and/or plasma. We measured the effect of NO donors and nitrite on three TEG parameters, reaction time (R, time to initial fibrin formation), α angle (velocity of clot growth) and maximum amplitude (MA, clot strength), in healthy volunteers. The NO donor (DEANONOate) inhibited all three TEG parameters in response to two independent platelet activators (ADP and AA), in platelet rich plasma (PRP) or whole blood diluted with plasma to yield 20% hematocrit (Hct) to model blood in the microcirculation in vivo. At DEANONOate concentrations ranging from 0-1 μM, R values were progressively prolonged from 1.9 to 3.6 (p=0.008), α angle was decreased from 17.8 to 9.5 (p=0.01) and maximum clot amplitude was reduced from 9.0 to 4.4 (p=0.001) in 20% Hct with ADP stimulation. In contrast, nitrite did not affect clotting parameters in PRP, but exhibited moderate inhibitory effects in 20% Hct at concentrations from 0-10 μM; R values were slightly prolonged from 1.6 to 2.7 (p=0.12), α angle was decreased from 21.8 to 12.8 (p=0.07) and maximum clot amplitude was reduced from 11.0 to 5.0 (p=0.02). This inhibitory effect of nitrite on clotting was greatly enhanced under hypoxic conditions (blood pO2 46.5±11.6 mmHg); R values from 1.4 to 4.0 (p=0.003), α angle from 21.7 to 7.8 (p=0.002), and maximum clot amplitude from 10.0 to 3.4 (p=0.0003). These results suggest that the nitrite effect may be greatest in the microcirculation and be important in differences between arterial and venous clotting. In conclusion, our results show TEG parameters indicate NO inhibition of platelet-mediated blood clotting and that the physiological effect of factors which determine NO bioavailability, such as reduction of blood and tissue nitrite, could be used to predict hemostasis. Disclosures: Schechter: National Institutes of Health: Dr. Alan Schechter is listed as a co-inventor on several patents issued to the National Institutes of Health for the use of nitrite salts for the treatment of cardiovascular diseases., Dr. Alan Schechter is listed as a co-inventor on several patents issued to the National Institutes of Health for the use of nitrite salts for the treatment of cardiovascular diseases. Patents &amp; Royalties.

Variations in Ex-Vivo Assessments of Hemostasis.

Previous studies have described differences in hemostasis between Caucasians and African-American subjects, suggesting that ethnicity may influence parameters used to monitor hemostasis. During the course of post-hoc analyses of data from an ex-vivo model to evaluate hemostasis in healthy, non-coagulopathic individuals, evidence of ethnic variability was noted. In this study, ex-vivo assessments of hemostasis were conducted using the thromboelastograph assay (TEG), and Hemodyne Hemostasis Analyzer (HHA). These instruments provide an assessment of platelet function and clot formation. All the subjects enrolled in this trial were healthy male volunteers between the ages of 18 and 45 years. Of the 48 subjects enrolled, 34 (71%) were Caucasians and 14 (29%) were African-Americans. Analyses were performed comparing blood loss volume (assessed by systematic recording of filter paper weights), duration of bleeding, TEG and HHA tracings between the two groups. There were no significant differences in blood loss volume and duration. However in the African-American subjects, TEG analyses demonstrated a significantly higher clot growth rate and maximum clot amplitude strength, while HHA analyses demonstrated a significantly higher platelet contractile force. These observations suggest that ethnic differences in coagulation parameters may exist that could influence techniques or instruments used to evaluate hemostasis. These observations require further investigation. In addition, these observation may provide a useful avenue for further investigation of the apparent enhanced coagulability in the African-American population.Ex-vivo Assessments of HemostasisAfrican-AmericanCaucasiann=14n=31Mean ± SDMean ± SDp-valueBlood loss volume (g)2.19 ± 1.162.58 ± 1.84NSBleeding duration (mins)21.07 ± 7.5220.0 ± 7.21NSTEG resultsCoagulation onset time (R, mins)4.93 ± 0.725.40 ± 0.89NSTime to 20 mm clot strength (K, mins)1.59 ± 0.251.95 ± 0.290.0004Clot growth rate (A, degrees)67.17 ± 3.7863.15 ± 3.690.0017Max. clot amp. Strength (MA, mm)61.07 ± 3.8957.63 ± 3.960.0096HHA resultsClot elastic modulus (CEM, Kdynes/cm2)20.01 ± 5.8015.87 ± 7.51NSPlatelet contractile force (PCF, Kdynes)5.50 ± 1.114.42 ± 1.440.0165NS, Not statistically significant

Thromboelastography, whole-blood haemostasis and recurrent miscarriage.

Some cases of recurrent miscarriage have a thrombotic basis. Thromboelastography is a rapid, reproducible test of whole-blood haemostasis. Thromboelastography was performed in 494 consecutive, non-pregnant women (median age 35 years; range 21-48) with a history of miscarriages at <12 weeks gestation (median 4; range 3-12) and 55 parous women (median age 33 years; range 20-41) with no history of pregnancy loss. The prospective outcome of untreated pregnancies amongst 108 women with recurrent miscarriage was studied. The maximum clot amplitude (MA) (median 66.0 mm; range 48.0-76.0) was significantly higher and the rate of clot lysis (LY30) (median 2.5%; range 0.5-7.8) significantly lower amongst women with recurrent miscarriage compared with controls (MA 61.5 mm; range 50.0-67.0; P = 0.01; LY30 4.9%; range 2.9-9.7; P = 0.01). The pre-pregnancy MA was significantly higher amongst women who subsequently miscarried (median 66.0 mm; range 54.0-73.0) compared with those whose had a live birth (median 61.7 mm; 48.0-71.5; P < 0.01). A pre-pregnancy MA >or=64 mm has a sensitivity of 68% and specificity of 82% to predict miscarriage. Thromboelastography identifies a subgroup of women with recurrent miscarriage to be in a prothrombotic state outside of pregnancy. Women in such a state are at increased risk of miscarriage in future untreated pregnancies.

Iron stores and coagulation parameters in patients with hypoxemic polycythemia secondary to chronic obstructive pulmonary disease: the effect of phlebotomies

This study was designed to determine the effects of phlebotomy on iron body contents and coagulation tests of COPD patients with polycythemia secondary to hypoxemia. Seventeen patients with COPD and hematocrits higher than 54 percent (mean Hct: 57 +/- 0.49 percent), who had not received anti-inflammatory or antiplatelet aggregation agents recently. Their mean forced expiratory volume at 1 second (FEV1) was 0.92 +/- 0.11 L. Blood work was collected to evaluate the following: serum iron and ferritin levels, total iron binding capacity, transferrin saturation index, fibrinogen plasma levels, activated partial thromboplastin time, platelet count, platelet aggregation measurements, and thromboelastography coagulation parameters. The blood samples were obtained before and about 7 days after the hematocrit correction by 300-400 ml phlebotomies done every other day. The mean number of phlebotomies done for each patient was 4.4. Postphlebotomy iron serum levels decreased from 90.1 +/- 14.8 to 59.7 +/- 9.9 mg/dl and the ferritin serum levels from 133.8 +/- 37.9 to 70.8 +/- 32.7 ng/ml (p < 0.05). Regarding the coagulation studies, there were significant increases in the platelet count, from 227,300 +/- 13,900 to 312,500 +/- 30,200 per mm3, and in the maximum clot amplitude (a) obtained by thromboelastography (from 53.6 +/- 1.4 percent to 60.4 +/- 1.1 percent). The coagulation time (k) of the thromboelastography also decreased significantly, from 7.5 +/- 0.7mm prephlebotomy to 4.5 +/- 0.3mm postphlebotomy. Although the coagulation changes were small amount, the observed significant decrease in iron contents may have clinical implications.

Pharmacological manipulation of gastric juice: thrombelastographic assessment and implications for treatment of gastrointestinal haemorrhage.

The impairment of formation and maintenance of a formed fibrin clot contributes to the prolonged bleeding and high incidence of rebleeding in upper gastrointestinal haemorrhage. To investigate the basis for the use of drug therapy in gastric bleeding, this study used thrombelastography to determine the effects of pharmacological manipulation of gastric juice on coagulation and fibrinolysis. The thrombelastograph is a mechanical device that provides a visual assessment of all stages of coagulation and fibrinolysis. The effects of fresh and pharmacologically changed gastric juice was assessed after its addition to fresh whole blood in the thrombelastograph cuvette. Pharmacological manipulation was achieved through alkalisation or through addition of tranexamic acid, aprotinin, or sucralfate. Fresh gastric juice delayed clot formation, decreased maximum clot amplitude, and stimulated clot lysis. Alkalisation inhibited the lytic effects of fresh gastric juice and improved the induced abnormalities in coagulation. Tranexamic acid partially inhibited gastric juice induced clot lysis but did not exhibit a beneficial effect on coagulation. Sucralfate, and to a lesser extent aprotinin significantly inhibited fibrinolysis but exacerbated the detrimental effect of gastric juice on the parameters of coagulation. Alkalisation of gastric juice reduces the adverse effect on coagulation and fibrinolysis. Tranexamic acid, aprotinin, and sucralfate can all reduce or inhibit clot lysis, but the adverse effects on clot formation may outweigh any potential benefit in the treatment of gastrointestinal bleeding.