Assessment of motor block

  • Bromage Score

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    © Children's Pain Management Service,
    The Royal Children's Hospital, Melbourne

    Rationale

    Local anaesthetics work by blocking nerve impulses on sensory, motor and autonomic nerve fibres. The smallest diameter fibres are most sensitive to the effects of local anaesthetics: autonomic fibres will be blocked first, then sensory fibres and then motor fibres. Motor nerves (as well as sensory nerves) may be affected by local anaesthetics. 

    It is important to assess motor block:

    • to determine the amount of motor function
    • to prevent pressure areas
    • to ensure the patient is safe to ambulate (if allowed)
    • to detect the onset of complications eg epidural haematoma or abscess 

    Procedure

    1. Explain the procedure and purpose to the child / parent.

    2. Assess the motor function: 
      Ask the patient to flex their knees and ankles. 
      For younger or disabled children (who are unable to follow commands) try to elicit movement by tickling toes, or gentle knee or hip flexion. 
      The degree of motor block on both the left and right side should be assessed.

    3. Rate their movement according to the Bromage score.

    4. With thoracic epidural, upper limb motor function should be assessed by testing bilateral hand and finger extension and flexion.

    5. Document the score on the Flowsheet (PCA/Epidural)
      If the motor function is different in each leg, document the scores accordingly, eg Bromage L) 2,  R) 0

    Assess motor block 4 hourly and at the following times:

    • In the recovery room following surgery
    • On return to the ward/unit from the operating suite
    • At commencement of each nursing shift
    • Prior to ambulation
    • 1 hour after a bolus or increase in the infusion rate

    Contact the Children's Pain Management Service if:

    • major changes in motor function (particularly any sudden change)
    • almost complete or complete motor block (Bromage score 2 - 3)
    • reduced hand or finger motor function with a thoracic epidural

    Adapted from Epidural Assessment Session, Fremantle Hospital Acute Pain Service, Fremantle, WA, Australia

    Devised October 2000, Updated Aug 2016