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

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

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

Brief Summary:

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.


Detailed Summary: 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.
Sponsor: University of Parma

Current Primary Outcome: Onset Time of Sciatic Nerve Block [ Time Frame: ≤30 minutes after block performance ]

Time to onset of sciatic nerve anesthesia, defined as both following criteria:

  • Sensory: does not feel pain or discomfort when pricked with a 25G needle.
  • Motor: able to slightly curl toes; unable to flex the ankle.


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Success Rate of Sciatic Nerve Blocks [ Time Frame: ≤30 min after block performance ]

    The percentage of patients who attain the criteria for block success within 30 minutes of the injection.

    Investigators will also report the percentage of patients who successfully complete surgery without significant additional analgesia (see below); this will be defined as "clinical success rate."

  • Incidence and Prevalence of Neurologic Disturbances [ Time Frame: 30 days after anesthesia performance ]

    Patients will be interviewed at ~4 h (block resolution visit), 7 days and (if necessary) at 30 days to assess for residual neurologic disturbances in the sciatic nerve territory.

    The incidence/prevalence of these phenomena will be noted.

  • Differences in Time to Resolution of Sciatic Nerve Block [ Time Frame: <12 h ]

    The time at which sensory and motor function of the sciatic nerve have recovered at least to the following criteria:

    • Sensory: patients feel discomfort when pricked with a thin needle (25G)
    • Motor: patients may move both toes and ankle, albeit with reduced strength

    This outcome measure will be examined by an investigator every 30-60 min and reported by patients as "time to return of sensation and movement". The investigator-reported value will be preferred if both are available.



Original Secondary Outcome: Same as current

Information By: University of Parma

Dates:
Date Received: November 25, 2013
Date Started: December 2011
Date Completion:
Last Updated: December 2, 2013
Last Verified: December 2013