Ultrasound Guidance for Interscalene Brachial Plexus Block

Ultrasound Guidance or Electrical Nerve Stimulation for Interscalene Brachial Plexus Block: a Randomized, Controlled Trial

This study has been designed to assess the possible advantages of using ultrasound imaging to block the brachial plexus (i.e., nerves of the upper limb) in patients undergoing shoulder surgery.

The ultrasound technique will be compared with the current gold standard, electrical nerve stimulation.

The aim of this study is to define which technique is better in terms of time to onset of anesthesia.

The study will compare real-time ultrasound (US) guidance and electrical nerve stimulation (ENS) in terms of onset time for interscalene brachial plexus anesthesia.

The main hypothesis is that direct visualization of neural structures under US guidance will grant better local anesthetic (LA) disposition around the roots of the plexus, thus improving onset times.

Perineural catheters will be used to maintain regional analgesia for 48 hours after surgery. We hypothesize that US guidance may also help physicians place perineural catheters more precisely, thus improving analgesia in the following hours to days.

Finally, we will investigate for possible differences in minor adverse events such as vascular puncture, pain during the anesthetic procedure.

Inclusion Criteria:

• ASA Physical Status Class I-III
• Elective surgery of the shoulder
• Informed consent to regional anesthesia

Exclusion Criteria:

• Inability to effectively communicate
• Chronic opioid use
• Absence of informed consent to participation to the study
• Ipsilateral upper limb neurological deficits
• Known allergy to study medications
• Contraindications to continuous block placement