GE CARESCAPE, User Manual

Page: 371 / 548

Neuromuscular transmission
Problem Solution
Difficulty in getting the response when locating the
nerve for plexus stimulation
●
You may try using the local muscle response as an
indication of current in the needle. If there is no
response, the needle may be broken.
●
Change the needle if necessary.
How can I verify the measurement reliability?
●
The reliability of the response can be estimated by
observing the bar graph or the NMT trend.
●
The bars of the bar graph should be in a smoothly
descending order from left to right, and the NMT
trend should indicate a fairly stable T1%. If this
is not the case, the latest response is unreliable.
Relaxation level does not usually decrease
significantly in one minute even with short-acting
relaxants.
●
To verify your observations, start a new
measurement manually right after the completion
of the previous measurement. Sometimes
the selected cycle time has been so long that
the relaxation level has changed considerably
between the measurements.
What can I do if the monitor does not find the
supramaximal stimulation current?
●
If the monitor is unable to find the supramaximal
stimulation current, check the electrode
placement. The nerve may be outside the dense
current flow or both the ulnar and median nerves
may be stimulated; progressively more muscle
activity is detected as the increasing stimulation
current activates new motor units. Consult the
figure below when placing the electrodes:
1. adductor pollicis
2. abductor digiti minimi (hypothenar)
3. flexor pollicis brevis (thenar)
4. ulnar medial
5. epicondyle
●
Also, supramaximal current may not be found if
the patient has anatomical and/or physiological
anomalies.
2062971-001 CARESCAPE Modular Monitors 371