Lesson 3 – Accelerometer Placement

This lesson will take you through accelerometer placement and precautions.

Setup Requirements

To complete this lesson, you will need:

  1. Stimpod NMS450X Neuromuscular Monitor
  2. NMT Monitoring Cable AMG
  3. Xavant NMT Electrode or two ECG electrodes

Selecting a monitoring site

Every time you use the Stimpod, you must first determine which site will be best suited for TOF monitoring.

There are two main considerations when selecting the site: Which appendage is available for the attachment of the accelerometer? And will the appendage be free to move without restriction?

1.1. Monitoring of the Ulnar nerve (preferred site)

1.2. Attachment of accelerometer to appendage

The accelerometer can be placed anywhere on the thumb as long as it is above the knuckle.

Top Tip

To prevent the hand position from interfering with the accelerometer movement, adjust the sensor to outside the “pocket” of the palm.

2.1 Monitoring of Posterior Tibial Nerve (alternative site)

Top Tip

There is a longer (3.5m) monitoring cable available for the STIMPOD that will negate the possible disadvantage of the nerve stimulator moving away from the head of the patient where most of the monitoring occurs.

2.2. Accelerometer placement on the big toe

The accelerometer can be placed anywhere on the big toe so long as it is above the knuckle.

Top Tip

Ensure accelerometer strap is the appropriate length to fit the corresponding appendage. A longer accelerometer strap is available for larger appendages.

3.1 Monitoring of the facial nerve (alternative site)

Warning

Facial nerve monitoring has been shown to have a fivefold risk of postoperative residual curarization.1

1 Intraoperative neuromuscular monitoring site and residual paralysis. Thilen SR, Hansen BE, Ramaiah R, Kent CD, Treggiari MM, Bhananker SM. Anesthesiology. 2012 Nov; 117(5):964-72.

3.2. Accelerometer placement on the face

When applying the accelerometer to the face, the strap must first be removed, and double-sided tape applied to the bottom of the accelerometer.

To monitor the Corrugator Supercilli muscle, place the accelerometer on the eyebrow.

To monitor the Obicularis Oculi muscle, place the accelerometer in the eyelid.

Warning

Facial nerve monitoring should not be used in close proximity to EEG electrodes, such as BIS monitoring.

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