Altered regulation of in-vivo coagulation in orthopedic patients prior to knee or hip replacement surgery

Effect of age on the functioning of hemostasis system during hip joint endoprosthesis

The study was performed on 109 osteoarthritis patients who underwent hip joint endoprosthetics; the effect of age on changes in hemostasis system, blood loss level and deep veins thrombosis development in the background of standard prevention with low-molecular heparins were studied. Before the surgery, it was determined that 56 elderly patients (60.3 ± 6.4 years) compared to 53 middle-aged patients (41.8 ± 6.8 years) had a significantly higher initial and postoperative endothelial dysfunction, higher fibrin formation and lower anticoagulant potential; however, it was found that on the background of pharmacological anticoagulant therapy the changes in the hemostasis functioning in elderly patients did not lead to an increase of either blood loss or the number of thromboses.

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.

Fibrinolytic Dysregulation in Total Joint Arthroplasty Patients

Background:

The alterations of the fibrinolytic components in osteoarthritic joint disease and their postsurgical modulation are not clearly understood. Preexisting hemostatic dysfunction may lead to both thrombotic and bleeding events in these patients.

Aim:

To profile fibrinolytic parameters in patients undergoing total joint arthroplasty prior to and on postoperative day 1.

Methods:

A total of 98 total joint arthroplasty patients were included in this study. Blood samples were drawn preoperatively and on postoperative day 1 status posttotal knee or total hip arthroplasty surgery. d-Dimer, plasminogen activator inhibitor 1 (PAI-1), and tissue plasminogen activator (tPA) were measured using commercially available enzyme-linked immunosorbent assay kits. Antiplasmin activity was measured by using a functional method.

Results:

Preoperative PAI-1, d-dimer, and tPA levels were significantly higher in arthroplasty patients compared to healthy controls. Preoperative antiplasmin level was lower than controls. Postoperative levels of PAI-1 and d-dimer were increased compared to preoperative values. Postoperative antiplasmin values were lower than preoperative levels. Changes in tPA was not significant. There was no correlation between preoperative PAI-1 and d-dimer levels. Pre- and postoperative percentage changes in each individual were calculated for PAI-1, d-dimer, tPA, and antiplasmin. There was a positive correlation between d-dimer and PAI-1. Negative correlations between antiplasmin and d-dimer and between antiplasmin and PAI-1 were noted.

Conclusion:

These results confirm the perturbation in the fibrinolytic system of patients undergoing total joint arthroplasty surgery. Surgical intervention may also enhance the observed changes. The alterations in the fibrinolytic system may lead to the observed hemostatic complications such as bleeding, hematoma formation, or potential need for blood transfusion.

[Comparison of hemostatic markers under different techniques for anesthesia-analgesia in total hip or knee replacement]

BACKGROUND AND OBJECTIVE

Surgery promotes a state of hypercoagulability, predisposing to the possibility of postoperative thromboembolic complications. Our aim was to determine whether certain combinations of techniques (neuraxial, intravenous or both) for anesthesia and analgesia might be associated with attenuation of the prethrombotic state following total hip or knee replacement.

METHODS

Prospective longitudinal study of 45 patients undergoing elective hip or knee prosthetic surgery. The patients were randomized to 3 groups to receive different anesthesia-analgesia combinations: spinal-intravenous, spinal-epidural, or general-intravenous. From induction until 36 hours after surgery, we recorded the postoperative time course of the following markers of coagulation and fibrinolysis: platelet count; fibrinogen level; activated partial thromboplastin time; international normalized ratio; and levels of prothrombin activation fragments 1 and 2, thrombin-antithrombin III complex, and D-dimer.

RESULTS

No statistically significant between-group differences were found in patient demographic, clinical, surgical or postoperative data. No symptomatic thromboembolic complications or deaths were recorded in the 30 days after surgery. Statistically significant differences were found in laboratory results for samples taken 36 hours after surgery. Patients who received spinal-epidural anesthesia and analgesia had lower levels of prothrombin activation fragments 1 and 2 and longer activated partial thromboplastin times than the group receiving the spinal-intravenous combination.

CONCLUSIONS

The anesthetic technique used during surgery did not affect hemostasis. However, continuous epidural analgesia in the postoperative recovery period attenuated some markers of hypercoagulability.

Hypercoagulability after trauma: hemostatic changes and relationship to venous thromboembolism

BACKGROUND

Major trauma induces a hypercoagulable state, which is frequently complicated by pathological thrombosis. However the sequential changes in coagulation markers and their relationship to clinical thrombosis have been poorly characterized.

METHODS

We measured several markers of in vivo coagulation and fibrinolysis and their regulation serially for 2 weeks after multi-system trauma in a prospective cohort of patients who received no anticoagulant prophylaxis. Asymptomatic deep vein thrombosis (DVT) was assessed by routine bilateral venography between day 12 and 14. Clinically suspected DVT and pulmonary embolism (PE) were investigated in a standardized manner.

RESULTS

Among the 135 cohort patients the overall venous thromboembolism (VTE) rate was 59%. Markers of thrombin generation were markedly increased within 24 hours of injury, remained persistently elevated for about 5 days and then decreased by day 14. No early compensatory increase in Tissue Factor Pathway Inhibitor (TFPI) or the complex of Factor Xa and TFPI (FXa-TFPI) was seen; FXa-TFPI remained depressed throughout the study. There was no inverse relationship demonstrated between markers of thrombin generation and thrombin regulation. Acquired APC resistance and hypofibrinolysis did not appear to be important contributors to hypercoagulability after trauma. None of the coagulation markers were independently predictive of VTE. Increasing age was the only significant, independent predictor of VTE.

CONCLUSION

Major trauma leads to significantly increased and persistent thrombin generation with disruption of its regulation. Coagulation markers do not appear to add independent predictive value in detecting VTE. Increasing age is the most important clinical predictor of VTE after trauma.