O papel do ácido tranexâmico na prevenção e gerenciamento da perda de sangue na artroplastia total de articulação

Objective  To collect data on the role played by tranexamic acid in the prevention and management of blood loss in patients undergoing total hip arthroplasty and total knee arthroplasty.

Methods  In the present prospective, comparative study, 30 patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) were randomly allocated into 1 of 2 groups with 15 patients each. Tranexamic acid was administered by intravenous and topical routes in the study group, but it was not administered in the control group. Preoperative blood parameters, intraoperative and postoperative blood loss, and need for blood transfusion were noted. Statistical analysis was performed using the chi-squared test and the independent t -test.

Results  The study group had statistically significant higher postoperative hemoglobin values ( p  = 0.03), less difference between pre and postoperative hemoglobin value ( p  = 0.046), less difference between pre and postoperative packed-cell volume ( p  = 0.06), less intraoperative measured blood loss ( p  = 0.015), and less volume of blood collected in the drain ( p  = 0.0291) compared with the control group. There was also reduced frequency of blood transfusions in the study group ( p  = 0.0008).

Conclusion  Tranexamic acid is associated with reduced intra and postoperative blood loss and reduced frequency of blood transfusions in patients undergoing THA/TKA.

Altered Fibrinolysis during and after Surgery

Major surgery induces hemostatic changes related to surgical stress, tissue destruction, and inflammatory reactions. These changes involve a shift of volume from extravascular space to intravascular and interstitial spaces, a "physiologic" hemodilution of coagulation proteins, and an increase of plasmatic fibrinogen concentration and platelets. Increases in fibrinogen and platelets together with a simultaneous dilution of pro- and anticoagulant factors and development of a hypofibrinolytic status result in a postoperative hypercoagulable state. This profile is accentuated in more extensive surgery, but the balance can shift toward hemorrhagic tendency in specific types of surgeries, for example, in prolonged cardiopulmonary bypass or in patients with comorbidities, especially liver diseases, sepsis, and hematological disorders. Also, acquired coagulopathy can develop in patients with trauma, during obstetric complications, and during major surgery as a result of excessive blood loss and subsequent consumption of coagulation factors as well as hemodilution. In addition, an increasing number of patients receive anticoagulants and antiplatelet drugs preoperatively that might influence the response to surgical hemostasis. This review focuses on those situations that may change normal hemostasis and coagulation during surgery, producing both hyperfibrinolysis and hypofibrinolysis, such as overcorrection with coagulation factors, bleeding and hyperfibrinolysis that may occur with extracorporeal circulation and high aortic-portal-vena cava clamps, and hyperfibrinolysis related to severe maintained hemodynamic disturbances. We also evaluate the role of tranexamic acid for prophylaxis and treatment in different surgical settings, and finally the value of point-of-care testing in the operating room is commented with regard to investigation of fibrinolysis.

Efficacy of topical tranexamic acid within a blood-saving programme for primary total hip arthroplasty: a pragmatic, open-label randomised study

BACKGROUND

Total hip arthroplasty entails considerable peri-operative blood loss, which may lead to acute post-operative anaemia and red blood cell transfusion. This study was aimed at assessing whether the addition of topical tranexamic acid to our ongoing blood-saving protocol for total hip arthroplasty was effective and safe.

MATERIALS AND METHODS

A pragmatic, prospective, open-label randomised study of patients scheduled for total hip arthroplasty at a single centre was conducted. Consecutive patients were randomly assigned to receive topical tranexamic acid (2 g) at the end of surgery (tranexamic group, n=125) or not (control group, n=129). A restrictive transfusion protocol was applied. Outcome measures were red blood cell loss at 24 hours after surgery, in-hospital transfusion rate, and incidence of thromboembolic complications.

RESULTS

Topical tranexamic acid was effective in reducing both red cell loss (mean difference: 138 mL [95% CI 87-189 mL]; p<0.001) in the 24h after surgery and in-hospital transfusion rates (12 vs 32.6%, for the tranexamic acid and control groups, respectively; p<0.001; relative risk=0.37 [95% CI 0.22-0.63]). However, relative red cell loss and transfusion rates were higher in females than in males, irrespectively of tranexamic acid use. The beneficial effect of tranexamic acid on transfusion was restricted to patients with pre-operative haemoglobin ≥13 g/dL (5.1 vs 24.8%; p<0.001). Topical tranexamic acid was well tolerated and no clinically apparent thromboembolic complications were witnessed.

DISCUSSION

The use of topical tranexamic acid after hip arthroplasty reduced red cell loss and transfusion rates; the efficacy of this strategy may be improved by reinforcing both pre-operative haemoglobin optimisation and adherence to the practice of transfusing single units of red cells.

Depression Symptoms Facilitated Fibrinolytic Dysregulation and Future Coronary Artery Disease Risk in a Black Male Cohort: The Sympathetic Activity and Ambulatory Blood Pressure in Africans Study

BACKGROUND

Hypercoagulation is associated with coronary artery disease (CAD). Whether depression symptoms dysregulate inflammatory and hemostatic markers in an African cohort is not known; therefore, we assessed the relationship between depressive symptoms and inflammatory and hemostatic markers as potential CAD risk markers in an African sex cohort.

MATERIAL AND METHODS

We included 181 black African urban-dwelling teachers (88 men, 93 women; aged 25-60 years) from the Sympathetic Activity and Ambulatory Blood Pressure in Africans Study. The Patient Health Questionnaire was used to assess depressive symptoms. Fasting plasma concentrations of C-reactive protein, fibrinogen, D-dimer, plasminogen activator inhibitor-1 (PAI-1) and 24-hour blood pressure measures were obtained.

RESULTS

Moderately severe depression symptom status was similar in the black sex groups. Both sex groups showed a mean hypertensive state and low-grade inflammation (C-reactive protein > 3 mg/L). Levels of PAI-1 were higher in depressed men, whereas D-dimer levels were lower in depressed women when considering concomitant confounders. In black men only, depressive symptoms were associated with levels of PAI-1 (adj. R = 0.12; β = .22 [95% confidence interval, .0-.44]; P = .04) and D-dimer (adj. R = 0.12; β = .28 [95% confidence interval, .08-.48]; P = .01), independent of confounders.

CONCLUSION

In black men, depression symptoms accompanied by a mean hypertensive status may up-regulate inflammatory and thrombotic processes. Depression symptoms in black men facilitated hypercoagulation or fibrinolytic dysregulation and potentially increased their CAD risk. Early screening of fibrinolytic markers and for the presence of depressive symptoms is recommended.

Levels of Matrix-Degrading Enzymes and Lubricin in Patients With Degenerative Joint Disease Requiring Arthroplasty

Total joint arthroplasty (TJA) of the hip or knee (THA and TKA) is the primary surgical intervention for individuals with degenerative joint disease (DJD). Although it is commonly thought that shear force on the joint causes the degradation of articular cartilage, it is possible that there are other factors that contribute to the progression of DJD. It is plausible that specific enzymes that degrade the joint are upregulated, or conversely, there is downregulation of enzymes critical for joint lubrication. The aim of this study is to profile collagenase-1, elastase, heparanase, and lubricin levels in patients undergoing TJA in order to determine potential preexisting dysregulation that contributes to the pathogenesis of DJD. Deidentified blood samples were obtained from patients undergoing TJA 1 day pre- and 1 day postoperatively. Plasma samples were analyzed using enzyme-linked immunosorbent assay kits for elastase, collagenase-1, heparanase, and lubricin. In comparison to healthy controls, there were significant increases in circulating collagenase-1, elastase, and lubricin levels in both the preoperative and postoperative samples. There were no significant differences in heparanase levels in the preoperative or postoperative samples. Comparing the preoperative versus postoperative patient samples, only lubricin demonstrated a significant change. The results of this study confirm that patients undergoing TJA have preexisting alterations in the levels of matrix-degrading enzymes and lubricin. The alterations observed in this study may provide insight into the pathogenesis of DJD.

Dysregulation of Tissue Factor, Thrombin-Activatable Fibrinolysis Inhibitor, and Fibrinogen in Patients Undergoing Total Joint Arthroplasty

Total joint arthroplasty (TJA) of the hip or knee (THA, TKA) has become an increasingly common procedure. While TJA is a successful treatment for individuals experiencing degenerative joint diseases, it is well known that one of the most common perioperative complications of TJA is deep venous thrombosis (DVT). To profile tissue factor (TF), microparticle-tissue factor (MP-TF), thrombin-activatable fibrinolysis inhibitor (TAFI), and fibrinogen levels in patients undergoing TJA to determine potential preexisting Hemostatic dysregulation. De-identified blood samples were obtained from patients undergoing TJA 1 day pre- and 1 day postprocedure. Plasma samples were analyzed using enzyme-linked immunosorbent assay kits for fibrinogen, TAFI, TF, and MP-TF; fibrinogen levels were also assessed using a clot-based activity assay. In comparison with healthy controls, there were significant increases of fibrinogen and MP-TF levels, while there were significant decreases in TF and TAFI levels in the preoperative and postoperative patients. Comparing the pre versus postoperative patients, no significant differences were found; interestingly, however, surgical intervention exacerbated the changes found in the preoperative samples compared to the controls. The results of this study confirm that patients undergoing TJA have preexisting alterations in the fibrinolytic system. Surgical intervention tended to exacerbate these changes. The alterations observed in this study may provide insight as to why TJA is associated with higher rates of DVT and thromboembolism.