During surgery muscle relaxation can be monitored continuously to assess the need for either
repeated administration of a muscle relaxant or for the use of a reversal agent during recovery.
2.2
Checking patients for residual curarization
The use of the automatic set-up of the TOF-Watch on patients already relaxed will result in
incorrect selection of internal gain due to fading. The following procedure should be used:
1
Place electrodes in position, attach the acceleration transducer to the thumb with adhesive
tape.
2
Turn TOF-Watch on by pressing the
button (1) and holding it down for 1 s.
3
The strength of the stimulation (mA or µC) can be adjusted manually by pressing the
mA (µC) up (21) or down button (23).
4
Press (3).
Since no control twitch height has been established, only the TOF ratio yields information
about the recovery of a patient and not a single twitch measurement.
2.3
Nerve location for loco-regional anesthesia
The TOF-Watch can be used as an aid in nerve location for loco-regional anesthesia using a
special stimulation cable. This cable contains one lead with a connector fitting to a surface
electrode and one lead with a 2 mm plug to be connected to a needle electrode.
Once this cable is inserted in the TOF-Watch, the instrument automatically reverts to the loco-
regional anesthesia mode. Since only a visual assessment of the response is needed, no
responses are shown on the display.
1
Connect special stimulation cable to the TOF-Watch
2
Place the surface electrode in position
3
Turn TOF-Watch on by pressing the
button (1) and holding it down for 1 s.
4
Start the repetitive 1Hz stimulation by pressing the
(24) button.
5
The strength of the stimulation (mA or µC, shown on the display) can be adjusted manually
by pressing the mA (µC) up button (21) or down button (23).
The TOF-Watch is now ready for use in locating the nerve with the needle electrode.
3
Pre-Operative set-up
3.1
Cable connections (objective monitoring)
The TOF-Watch can be used for objective monitoring by using two cables:
A) acceleration transducer cable and B) stimulation cable.
When surface electrodes are used, the instrument automatically uses stimulation pulses of
200 µs (300 µs) at 0 - 60 mA (0 - 12/18 µC). The pre-defined default current is set at 50 mA.
Attach the stimulation cable to the surface electrodes placed on the ulnar nerve.
Attach the acceleration transducer with its’ largest flat side to the thumb by means of adhesive
tape. Connect both cables to designated color-coded outlets on the TOF-Watch (reversal of the
cables is not possible because of a mechanical barrier).
7
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TOF-Watch S
Operator manual 33.516/A
