Effects of different concentrations of ropivacaine in intermediate cervical plexus block combined with superior trunk block on diaphragmatic function

The aim of this study was to evaluate the effects of two different concentrations of ropivacaine, administered at equal total doses, on diaphragmatic function when used in an intermediate cervical plexus block combined with a superior trunk brachial plexus block in patients undergoing clavicular fracture surgery. A total of 60 patients scheduled for clavicular fracture repair were randomly assigned to receive either high-concentration ropivacaine (Group H) or low-concentration ropivacaine (Group L) in equivalent total doses. All patients underwent an intermediate cervical plexus block combined with a superior trunk brachial plexus block. Diaphragmatic function, block efficacy, and postoperative analgesia were evaluated and compared. All procedures were completed successfully. Two patients in Group L required supplemental analgesia with fentanyl. The incidence of diaphragmatic paralysis did not differ significantly between groups ( p > 0.05). Pinprick sensory block scores at 30 min post-block were comparable between groups ( p > 0.05). Visual Analog Scale pain scores, the need for rescue analgesia, and motor function assessed by the Modified Bromage Score within the first 24 h postoperatively showed no significant differences between the two groups. When administered at equal total doses, both 0.25% and 0.5% ropivacaine concentrations provided comparable anesthetic efficacy in intermediate cervical plexus block combined with superior trunk brachial plexus block. Based on anatomical considerations and previous literature, this combined technique is expected to have a lower incidence of diaphragmatic paralysis compared with the conventional interscalene combined with superficial cervical plexus block approach. It also, preserved partial motor function in the operative limb, and demonstrated a safe and effective anesthetic approach for clavicular fracture surgery. Trial registration : Prospectively registered in the Chinese Clinical Trial Register website, on December 20th, 2023 (ChiCTR2300078886).