Peripheral nerve blocks vs selective spinal anesthesia in patients with femur fracture: a patient-, surgeon-, and assessor-blinded randomized controlled study

BACKGROUND: Proximal Femur Fractures (PFF) are common among the elderly and can lead to significant disability. Anesthesiological management typically involves Spinal Anesthesia (SA) or Peripheral Nerve Blocks (PNBs). This study aimed to compare the efficacy and safety of SA and PNBs in elderly patients undergoing surgical fixation of PFF. The primary outcome was the comprehensive assessment of intraoperative hemodynamic instability. METHODS: A monocentric, patient-, surgeon-, and assessor-blind randomized study was conducted at the University 'Federico II' Hospital of Naples from December 2023 to June 2024. Patients diagnosed with PFF and scheduled for surgery were randomized to receive either Selective Spinal Anesthesia (SSA) (hypobaric bupivacaine 0.5% 7.5 mg and sufentanil 5 µg) or PNBs (femoral, lateral femoral cutaneous, obturator, and sciatic nerve blocks). The study evaluated the efficacy and safety of locoregional procedures by analyzing intraoperative and postoperative adverse events, as well as the effectiveness of analgesia. RESULTS: The PNB group showed a significantly lower incidence of intraoperative hemodynamic instability (16.7% vs 43.4%, p = 0.048) compared to the SSA group. Bradycardia was also less frequent in the PNB group (10% vs 33.3%, p = 0.028). Although repeated hypotensive episodes occurred in both groups, mean MAP, TWA-MAP and TWA-hypotension remained within safe limits, with brief episode durations and no need for pharmacological intervention. Mobilization was slower in the PNB group; however, these patients experienced a shorter hospital stay. No differences were observed in the need for analgesic rescue doses or in the incidence of postoperative complications, including PONV, DVT, MI, or neurological injury. Pain scores were slightly higher in the SSA group at 6 and 24 h, though the differences were not clinically meaningful. Both groups showed significant increases in NRS and PAINAD scores over time compared to baseline. Motor and sensory block onset was slower and duration longer in the PNB group, while SSA produced a faster onset and earlier resolution. Surgeon satisfaction, as well as estimated and actual surgical durations, were comparable between groups. CONCLUSIONS: PNBs offer an alternative to SSA by providing better intraoperative hemodynamic stability, a lower incidence of postoperative delirium, and improved postoperative analgesia. TRIAL REGISTRATION: This study is registered with Clinicaltrials.gov, number (NCT06155903), registered July, 2, 2023, https://clinicaltrials.gov/study/NCT06155903.