Dräger Infinity Delta, Instructions For Use Manual

Page: 420 / 614

24-2 D
ELTA
/D
ELTA
XL/K
APPA
VF8
24 N
EUROMUSCULAR
T
RANSMISSION
(NMT)
MONITORING
Overview
The Infinity Trident (NMT) pod is a stimulator pod for the measurement of
neuromuscular transmission (NMT) / neuromuscular blockade in adult or pediatric
mode.
The NMT pod provides automatic measurements of muscle response (thumb twitch)
to electrical stimuli transmitted via electrodes placed over the peripheral nerve (for
example Ulnar nerve). The NMT sensors measure muscle response as well as skin
temperature and send this information to the pod and monitor for display. An
accelerometer is used as the twitch sensor. A thermistor is used to measure skin
temperature. It is important to understand the pulse characteristics of the stimulator
(see monitoring modes on page 24-5 and specifications in appendix B for details).
At the start of NMT measurements, the pod sends several test pulses to the nerve in
order to establish a supramaximal current, which is the pulse strength necessary to
excite all the fibers in the nerve. Once the supramaximal current has been established,
the pod performs a reference measurement consisting of four pulses to establish a
reference muscle response level (reference twitch) in the unrelaxed patient. In
subsequent measurements, the pod can compare the relaxed patient’s muscle
responses to this reference twitch.
NMT values are displayed in the NMT parameter box and saved as trend values. You
can set NMT alarm limits on the Alarm Limits table (see page 24-5).
NOTE:
The NMT pod is not supported in neonatal mode.
Only EEG and BISx pods can be connected to the NMT pod.
NOTE:
The supramaximal current and reference twitch should be established before
you administer muscle relaxants to the patient.
If the pod cannot establish a supramaximal current based on an actual
measurement, it uses a set reference value of 60 mA.
If the pod cannot establish a reference twitch, it uses an internal reference value
for twitch response. A reference twitch is necessary for single-mode
measurements.
Patients with nerve damage or other neuromuscular problems may not respond
properly to stimulation. The NMT pod may show unusual patterns when
monitoring relaxation in these patients.