Study objective: To evaluate the profile of molecular hemostatic markers in patients receiving either spinal or balanced general anesthesia for total hip arthroplasty.
Design: Open, randomized, observational study.
Setting: Orthopedic unit and central laboratory of a university hospital.
Patients: 26 consenting ASA physical status II and III inpatients undergoing total hip arthroplasty with general balanced anesthesia (n = 10) or spinal (regional) anesthesia (n = 16).
Interventions: The time course of seven procoagulatory and fibrinolytic parameters was examined during and after surgery in both groups of patients (general and regional). Blood samples were drawn on the day before surgery, directly before induction of general anesthesia or regional anesthesia, respectively, intraoperatively (before bone manipulation), at the end of surgery, and on the mornings of postoperative days 1 and 5.
Measurements and main results: The coagulation samples were centrifuged within 1 hour of collection at 2,300 g for 15 minutes at 4 degrees C. Hemoglobin, hematocrit, platelets, fibrinogen, prothrombin time, thrombin time, activated partial thromboplastin time, antithrombin, and protein C were measured immediately on arrival at the laboratory. Specimens were then aliquoted and stored at -70 degrees C. Within 2 weeks, samples were thawed and prepared for the following assays: thrombin-antithrombin complexes (TAT complexes), D-dimers, plasminogen activator inhibitor type 1 (PAI-1), and plasminogen and plasmin inhibitor. Maximum activation of coagulation was not reached until 2 hours postoperatively and then slowly decreased until normal values were reached around the fifth postoperative day. Parameters displaying the greatest changes were antithrombin and D-dimers. No statistically significant differences were found between the two groups at the individual time points.
Conclusion: Our initial hypothesis that the lesser risk of postoperative DVT in patients undergoing total hip arthroplasty in regional anesthesia is reflected in the course of the plasmatic molecular markers of hemostasis could not be verified. There were no significant differences in the timely course of the markers at any given time point.