Efficacy of Ultrasound-Guided Local Anesthetic Injection Into or Around the Sciatic Nerve for Lower Limb Anesthesia

Intraneural Injection of Ropivacaine for Subgluteal Sciatic Nerve Block Leads to Faster Onset and Higher Success Rates: a Randomized, Controlled Trial

This study was designed to assess whether the injection of local anesthetic into the nerve (intraneural), as opposed to around it (perineural), requires a shorter time to develop surgical anesthesia of the lower leg.

The investigators will compare the two types of injection using the same drug, so as to determine if there is an actual difference onset time. They will also examine the overall success rate of either kind of sciatic nerve blocks as the sole anesthetic for non-emergent orthopedic surgery.

The safety of these procedures will be examined by in-hospital and phone-call follow-up contacts.

This will be a randomized, controlled, patient- and observer-blinded trial assessing block characteristics after intra- or perineural injection of ropivacaine for subgluteal sciatic nerve blocks performed for elective surgery of the lower limb.

Inclusion Criteria:

• Undergoing non-emergent orthopedic procedure of knee, leg, foot with thigh tourniquet
• ASA Physical Status Class I-III
• Consenting to surgery under peripheral nerve block anesthesia (sciatic + femoral/saphenous block)

Exclusion Criteria:

• Unable to understand or communicate for the purpose of the study
• Exhibiting any neurological disturbance of the ipsilateral lower extremity
• Inability to satisfactorily image the sciatic nerve in the opinion of the attending anesthesiologist