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Neuromuscular Transmission(NMT)
Monitoring Mode (NMS 450X)
3
Monitoring Neuromuscular Blocking Agent involves stimulating a neural pathway which
facilitates the contraction of an appendage. Based on the relative strength of contraction
which is the result of a stimulus of specific intensity or waveform, it is possible to draw
conclusions about the efficacy of an injected Neuromuscular Blocking Agent.
•
This mode is selected when the NMT cable is inserted.
Electrode Placement
Anatomical stimulation sites are chosen based on
•
their accessibility during surgery
•
the ability to observe the neuromuscular response
•
the nerve should be a suitable distance from the responding
muscle to prevent direct muscle stimulation
Anatomically ideal stimulation sites
Targeted Nerve
Affected Muscle
Contracting Appendage
Ulnar nerve
adductor pollicis muscle
Thumb
Posterior tibial nerve
flexor halluces brevis muscle Big toe
Targeted Nerve
Affected Muscle
Contracting Appendage
Facial nerve (Zygomatic
Branch)
orbicularis oculi muscle
Eye lid
Facial nerve (Temporal Branch) corrugator supercili
muscle
Eye brow
Electrode placement relies on the cathode (black electrode clip) to be as close to the
targeted nerve as possible in order to effectively depolarize the nerve. The anode (red
electrode clip) should be away from the targeted nerve.
Accelerometer Placement
The tri-axial accelerometer should be attached
to the contracting appendage of the patient,
to measure the strength of the contraction
resulting from the applied electrical stimulus.
Accelerometer is used in Train-of-Four, Double
Burst, Post Tetanic Count, Supra Maximal Current
and Auto modes, to facilitate monitoring of the
efficacy of the Neuromuscular Blocking Agent.
