Comparing continuous lumbar plexus block, continuous epidural block and continuous lumbar plexus block with a parasacral sciatic nerve block on post-operative analgesia after hip arthroplasty

Study Objective: To compare post-operative analgesia obtained by continuous lumbar epidural block (CLEB) versus continuous lumbar plexus block (CLPB) versus CLPB associated with a single shot parasacral sciatic nerve block (CLEBS) after total hip arthroplasty (THA). Study design: Randomized clinical trial. Setting: Operating room, postoperative care unit, orthopedic surgical ward. Methods: 78 ASA I-III patients undergoing elective THA were randomly assigned to receive CLEB (n=24, 15-20 ml of 5 mg/ml ropivacaine, sufentanil 10 mg, clonidine 1 mg/ml), CLPB (n=22, 3mg/kg of 5 mg/ml of ropivacaine, max. 40 ml, clonidine 1 mg/ml, sufentanil 10 mg) or CLPBS (n=23, CLPB as described above; sciatic nerve: 20 ml of ropivacaine 5 mg/ml, clonidine 1 mg/ml). All patients received continuous infusion of 2 mg/ml of ropivacaine, 8 ml/h for 48 hours. Primary outcome was pain intensity assessment (VAS and VS). Secondary outcomes were postoperative total opioid consumption, hemodynamic stability, motor blockade, blood loss, intraoperative sufentanil and propofol consumption, patient satisfaction and complications. Results: VAS was lower in the CLEB group than in the CLPB and CLPBS groups respectively for 6 and 12 hours postoperatively (post-surgery p<0.001, 2h p<0.001, 6h p<0.001, 12h p<0.03)(Table 2). Moreover, CLPSB patients reported lower VAS than CLPB patients from the end of the surgery till the 12th follow up hour (Table 2). VS was lower in the CLEB group from the end of surgery to 6h postoperatively (Table 3). The CLPB group showed higher morphine consumption than the CLPSB and CLEB groups over 12 h postoperatively (p=0.05); thereafter, no statistically significant diferences were observed between groups at the end of follow up (48h) (p=0.4) (Table 4). onclusion: In conclusion, continuous lumbar plexus block in association with single shot sciatic nerve block is a valid alternative to epidural technique in managing postoperative analgesia after THA, with an improved risk-benefit balance