Onset and Recovery of Ultrasound Guided Out-of-plane Versus In-plane Interscalene Block in Arthroscopic Shoulder Surgery
Condition: Analgesia
Study type: Interventional

Summary: 
      The aim of this study was to assess the out-of-plane versus the in-plane approaches for the
      interscalene brachial plexus block; as regards the performance time, the onset, the
      progression and the recovery of sensory block, the onset and progression of the motor block
      as well as, the postoperative pain score and the duration of analgesia for arthroscopic
      shoulder surgery. A total of 60 patients of American Society of Anesthesiologists (ASA)
      physical status I-II were randomly divided to receive either the in-plane approach (Group I),
      or the out-of-plane approach (Group O).
    

Detailed description: 
      60 patients of ASA physical status I - II, greater than or equal to 30 years old and smaller
      than or equal to 60 years old, scheduled to undergo arthroscopic shoulder surgery in the
      lateral position; under ultrasound -guided interscalene brachial plexus block (ISPB) in this
      randomized study at Ain-Shams University Hospitals. On arriving to the operating theater,
      patients had an 18G intravenous cannula inserted in the non-operative upper limb side. All
      patients received; 0.05 mg/kg IV midazolam hydrochloride and 30 mg pethidine. Intraoperative
      basic monitors were applied using 5-leads ECG, pulse oximetry, non-invasive blood pressure
      (NIBP) and capnography (sample tube inserted under the O2 mask).A simple O2 mask at a flow of
      6L/min was applied. Infusion of Ringer's solution was then started at a rate of 5mL/kg/h
      throughout the surgery. Patients were placed in the supine position with their heads rotated
      towards the non-operative side. Iodine solution was used as an antiseptic on the operative
      neck side and then the patient head, neck and chest were draped. Local infiltration of the
      skin at the point of needle insertion was carried out with 2 ml lidocaine hydrochloride 1%,
      then a sterile 50-mm 22-G insulated needle was used for performance of the block.The
      ultrasound with a high frequency linear transducer was used, with the depth setting of 2-4
      cm. Distal to proximal (Trace back) approach was used; the supraclavicular fossa was scanned
      first to identify the subclavian artery as it passes over the first rib; by placing the probe
      against the clavicle and scanning in a caudate direction. The brachial plexus was easily
      identified as bunch of grapes supero-lateral to the artery. The plexus was followed medially
      and cephalad along its course by keeping the nerves in the center of the screen, to identify
      the brachial plexus roots between the anterior and the middle scalene muscles at the level of
      the sixth cervical vertebra deep to the sternocleidomastoid muscle.

      Patients were then divided into 2 equal groups of 30 patients each:

      Group I: An in-plane approach was used for the interscalene block. The needle was brought in
      the same plane as the probe at a shallow angle to the skin, some distance away from the edge
      of the probe in a lateral to medial direction so that the whole length of the needle can be
      visualized. After negative aspiration and assurance that high resistance to injection was
      absent, the LA was injected in a 5 ml increment below the lower root, between the 3 roots and
      above the upper root.

      Group O: An out-of-plane approach was used for the interscalene block. The needle was
      inserted cranial to the probe and after negative aspiration and assurance that high
      resistance to injection was absent, the LA was injected in a 10 ml increment; lateral and
      medial to the nerve roots. The needle appeared as a bright dot on the screen and by tilting
      the probe, the tip was identified as the point where further tilting leads to no longer
      visualization of the bright dot on the screen.

      After completion of the LA administration, the time was recorded as a baseline for the time
      interval. The assistant who recorded the data was blind to the patient groups. The sensory
      block was assessed by a pin-prick test using a 3-point scale. The motor block was assessed
      according to the shoulder, arm and fingers movement using a 3-point scale. Postoperative pain
      was measured at rest using the VAS score
    

Intervention name(s): Bupivacaine Hydrochloride in-plane approach for the interscalene block; Bupivacaine Hydrochloride out of-plane approach for the interscalene block
Intervention type(s): Drug; Drug
Intervention description(s): 20 ml of 0.5% bupivacaine added to them 50 μg adrenaline in a concentration of 1:400,000, were prepared by an assistant immediately before administration and injected in an in-plane approach to the brachial plexues; 20 ml of 0.5% bupivacaine added to them 50 μg adrenaline in a concentration of 1:400,000, were prepared by an assistant immediately before administration and injected in an out of-plane approach to the brachial plexues
Intervention MeSH terms: Bupivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Prevention