Costoclavicular and paracoracoid ultrasound-guided infraclavicular blocks resulted in similar onset times. Furthermore, no intergroup differences were found in terms of performance times and success rates. Future dose-finding trials are required to elucidate the minimum effective volume of local anesthetic for costoclavicular infraclavicular blocks. This trial was registered at www.clinicaltrials.in.th (Study ID: TCTR20160525001).

For ultrasound-guided costoclavicular block, the MEV90 of lidocaine 1.5% with epinephrine 5 μg/mL is 34 mL. Further dose-finding studies are required for other concentrations of lidocaine, other local anesthetic agents, and multiple-injection techniques.