Randomized Comparison of Extrafascial Versus Subfascial Injection of Local Anesthetic During Ultrasound-Guided Supraclavicular Brachial Plexus Block

• Published in: Regional anesthesia and pain medicine Vol. 40; no. 4; pp. 337 - 343
• Main Authors: Sivashanmugam, T, Ray, Suja, Ravishankar, M, Jaya, V, Selvam, E, Karmakar, Manoj Kumar
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 01.07.2015
• Subjects: Adult; Anatomic Landmarks; Anesthesia; Anesthetics, Combined - administration & dosage; Anesthetics, Combined - adverse effects; Anesthetics, Local - administration & dosage; Anesthetics, Local - adverse effects; Brachial plexus; Brachial Plexus Block - adverse effects; Brachial Plexus Block - methods; Bupivacaine - administration & dosage; Bupivacaine - adverse effects; Drug Combinations; Epinephrine - administration & dosage; Epinephrine - adverse effects; Female; Humans; India; Injections; Lidocaine - administration & dosage; Lidocaine - adverse effects; Local anesthesia; Male; Middle Aged; Motor Activity - drug effects; Orthopedic Procedures - adverse effects; Pain Measurement; Pain Threshold - drug effects; Pain, Postoperative - diagnosis; Pain, Postoperative - etiology; Pain, Postoperative - prevention & control; Prospective Studies; Regional anesthesia; Surgery; Time Factors; Treatment Outcome; Ultrasonic imaging; Ultrasonography, Interventional; Upper Extremity - innervation; Upper Extremity - surgery; Young Adult; India
• ISSN: 1098-7339; 1532-8651
• DOI: 10.1097/AAP.0000000000000264

The optimal site for local anesthetic injection during an ultrasound-guided supraclavicular brachial plexus block (BPB) is not known. We tested the hypothesis that local anesthetic injected deep to the "brachial plexus sheath" during supraclavicular BPB would produce faster onset of surgical anesthesia than an injection superficial to the sheath. After research ethics approval and informed consent, 32 patients undergoing upper-extremity surgery under an ultrasound-guided supraclavicular BPB were randomly assigned to receive 25 mL of a 1:1 mixture of 2% lidocaine with 1:200,000 epinephrine and 0.5% bupivacaine, deep to (subfascial, Gp SF) or superficial to (extrafascial, Gp EF) the brachial plexus sheath. Sensory-motor blockade of the ipsilateral musculocutaneous, median, radial, and ulnar nerves and time to "readiness for surgery" (defined as a sensory and motor block scale of 1 in all the 4 nerves tested) were assessed by a blinded observer, using a 3-point qualitative scale (2 to 0), every 5 minutes for 40 minutes and at 2, 4, 6, 8, 10, 12, and 24 hours after surgery. The time to "readiness for surgery" was significantly shorter (Gp SF: 7 ± 3 minutes vs Gp EF: 20 ± 10 minutes; P < 0.001), and the duration of postoperative analgesia was longer (Gp SF: 9.3 ± 1.4 hours vs Gp EF: 6.1 ± 1.4 hours; P < 0.001) in the subfascial group than in the extrafascial group. There were no complications directly related to the technique or the local anesthetic injection. Injection of local anesthetic deep to the brachial plexus sheath at the supraclavicular fossa, under ultrasound-guidance, results in faster onset of surgical anesthesia and prolonged duration of postoperative analgesia than an injection superficial to the sheath.