Sciatic Nerve Block for Ankle/Foot Surgeries. A Comparison Between a Premixed Solution of Lidocaine Plus Bupivacaine and Consecutive Infiltration of Lidocaine and Bupivacaine

Cork University Hospital

Status and phase: Completed; Phase 4

Conditions: Open Reduction Internal Fixation(ORIF) of Lateral Malleolus

Treatments: Drug: 2% lidocaine/adrenaline and 0.5% bupivacaine

Study type: Interventional

Funder types: Other

Identifiers

NCT01756443

SQ-PM-40

JR-786-GI

Details and patient eligibility

About

Regional anaesthesia has become the cornerstone of multimodal analgesia. With the advent of ultrasound guided nerve blocks regional anaesthesia has achieved both greater efficacy and a better safety profile as the injection of local anaesthetic is performed under direct vision. This has allowed a reduction of the amount of local anaesthetic injected as compared to peripheral nerve stimulation technique . Blockade of sciatic nerve combined with saphenous nerve provides anaesthesia and analgesia for ankle/foot surgeries. Various combinations of local anaesthetics have been used to provide optimal blockade . A mixture of lidocaine with a long acting local anaesthetic is commonly used. This provides a rapid onset of blockade, but of a consistently shorter duration compared to a long acting local anaesthetic alone. We hypothesize that sequential perineural injection of lidocaine and bupivacaine provides similar onset but a longer duration of sensory block compared to the same dose and volume of local anaesthetic mixed in advance.

Enrollment: 40 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients with ASA 1 - 3 status
• scheduled to undergo semi-elective ankle/foot surgery under regional anaesthesia +/- sedation/opioid free general anaesthesia will be recruited

Exclusion criteria

• Patients having surgery on the medial aspect of the ankle/ foot
• allergy to local anaesthetics
• coagulopathy
• malignancy or infection in the popliteal area
• significant peripheral neuropathy
• neurologic disorder of the lower extremity
• any other contraindication to sciatic nerve block
• pregnancy
• history of alcohol or drug dependency/abuse (defined as >40 IU/week)
• a history of significant cognitive or psychiatric disorder that may affect patient assessment

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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40 participants in 2 patient groups

Premixed group

Active Comparator group

Description:

Patients will receive sciatic nerve block with premixed 7.5 mls of 2% lidocaine/adrenaline and 7.5 mls of 0.5% bupivacaine followed by an interval of 90 seconds with an injection of same amount of both drugs.

Treatment:

Drug: 2% lidocaine/adrenaline and 0.5% bupivacaine

Sequential Group

Experimental group

Description:

Patients will receive a sciatic nerve block with 15 mls of 2% lidocaine/adrenaline followed by an interval of 90 seconds with 15 mls of 0.5% bupivacaine.

Treatment:

Drug: 2% lidocaine/adrenaline and 0.5% bupivacaine