A randomized clinical trial comparing six techniques of postoperative analgesia for elective total hip arthroplasty under subarachnoid anesthesia with opioids

Abstract

Optimal control of acute postoperative pain and prevention of chronic persistent pain in total hip arthroplasty (THA) remain a challenge. The main hypothesis was that peripheral nerve blocks improve postoperative analgesia. Immediate postoperative pain (24 hours) was evaluated every hour in 510 patients using a verbal rating 11-point scale for patient self-reporting of pain (VRS-11). All patients received subarachnoid anesthesia (SA) and were randomly allocated in six groups: SA with morphine 0.1 (SA0.1) or 0.2 mg (SA0.2), fascia iliaca compartment block with dexamethasone 4 mg + levobupivacaine 0.375% 20 (FICB20) or 30 mL (FICB30), lateral femoral cutaneous nerve block with levobupivacaine 0.25% 5 mL (LFCNB) and FICB20+LFCNB. Standardized analgesia included intravenous metamizole magnesium, dexketoprofen and rescue with paracetamol and morphine, and/or regional rescue (FICB, LFCNB, femoral and sciatic nerve blocks). About 37.5% of patients had at least one episode of pain, 31.3% of them needed rescue analgesia while the remaining 6.2% did not request analgesia. There were no significant differences between the groups in paracetamol, morphine and rescue nerve blocks requirements. There was pain only in 5.4% of the total PACU pain records: 3.1% mild pain, 1.7% moderate pain and 0.6% severe pain. combined with a multimodal analgesic approach, infra-inguinal FICB and LFCNB did not improve immediate postoperative analgesia for THA in our hospital. Other options and longer-term studies should be more extensively investigated to determine the role of peripheral blocks in postoperative pain treatment protocols.