Nerve guidance with versus without prepuncture ultrasound visualization for psoas compartment block and perineural catheter insertion: A randomized, prospective, blinded study

Abstract Lumbar plexus block may offer significant advantages in terms of postoperative analgesia, patient satisfaction, surgical outcome and patient rehabilitation. Ultrasound guidance has been used to describe psoas compartment block-related anatomy and to estimate transverse process depth before needle insertion and prediction of actual needle-to plexus intercept depth. The aim of this prospective randomized blinded study is to compare the Nerve-Stimulation Guidance with versus without the Pre-puncture Ultrasound Visualization in terms of onset time of the lumbar plexus sensory and motor block in patients undergoing total hip replacement. 46 patients undergoing total hip replacement were randomly allocated to receive posterior lumbar plexus block (LPB) using nerve stimulation guidance with (group US, n  = 23) or without pre-puncture ultrasound imaging (group NS, n  = 23). Onset time of sensory and motor blocks was recorded every 5 min for the first 30 min starting from the injection of the local anesthetic injection. Readiness for surgery was defined as complete numbness to pinprick test in the region supplied by the lumbar plexus and Bromage’s score = 3. Need for additional local anesthetic boluses or general anesthesia, intraoperative opioid consumption and first postoperative 24 h local anesthetic and rescue Analgesics consumption were also recorded. The time required for the execution of the block was 3 (2–15) min in Group US and 5 (2–20) min in Group NS ( p  = 0.06). The mean time to readiness for surgery was 12 ± 5 in Group US and 19 ± 6 min in Group NS ( p  = 0.04) . 3 Patients in Group US (13%) and 4 patients in Group NS (17%) ( p  = 0.73) required general anesthesia due to failed block. Intraoperative opioid consumption was similar in the two groups. There were no differences in complications, postoperative local anesthetic and rescue analgesics consumption and pain scores. Nerve-Stimulation technique combined with Pre-puncture Ultrasound Visualization for continuous lumbar plexus blocks is comparable to Nerve-Stimulation technique in terms of percentage of block success, intraoperative opioid consumption and postoperative pain relief. Pre-puncture Ultrasound Visualization may reduce the time required for readiness to surgery.