Selective spinal anesthesia using low concentration bupivacaine and fentanyl versus ordinary bupivacaine as a prophylaxis against deep venous thrombosis in total hip replacement surgery

Objective The aim of the present study was to detect the efficacy of early postoperative calf muscle exercise to decrease the risk of deep venous thrombosis achieved by intrathecal 3 ml bupivacaine 0.25% and fentanyl 25 μg instead of 3 ml bupivacaine 0.5%. In total, 40 patients of either sex, aged between 18 and 60 years, with American Society of Anesthesiologists (ASA) I and II were included in the study. Patients and methods A total of 40 ASA I and II patients undergoing elective total hip replacement surgery were randomly assigned to two equal groups of 20 patients each (group A and B). Group A received bupivacaine 0.5% (3 ml) and group B received bupivacaine 0.25% (3 ml)+fentanyl 25 μg. Patients were instructed on how to do cuff muscle exercise once they regained the full strength of the lower limbs muscles postoperatively. Five venous blood samples were taken from each patient for the D-dimer assessment as an indicator for the occurrence of venous thromboembolism. The first sample was taken preoperatively at the time of induction of anesthesia; the rest of samples were then taken at 12, 24, 48 h, and 7 days postoperatively. Results Group B, in which patients received intrathecal bupivacaine 0.25% plus fentanyl, had an earlier recovery of motor power; patients in this group started doing calf muscle exercise earlier than did those in group A, and this group had significantly lower postoperative D-dimer level, denoting less susceptibility to deep venous thrombosis. Conclusion Early postoperative calf muscle exercise decreased the incidence of venous thromboembolism risk as indicated by the results of the D-dimer assessment.