NuVasive NVM5 Manual De Instrucciones página 22

WARNINGS AND PRECAUTIONS cont.
PRECAUTION: The NVM5 System is to be used only as an adjunct to medical judgment
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and appropriate surgical practices. Dilator insertion and advancement should be
conducted only after careful analysis of radiographic images of the operative target area.
While a positive EMG detection by the NVM5 System can be associated with a high level
of certainty that a nerve is in close proximity to the Dilator tip, the absence of such an
EMG detection cannot be construed as a certain indication that no nerves are close to the
Dilator tip. Do not advance Dilator probes until all available data have been considered.
PRECAUTION: Do not advance the Dilator faster than the rate of update of Detection
data.
PRECAUTION: A thorough cleaning and preparation of the dermal surface prior to
placement of recording electrodes is required to assure proper adherence and sensitivity
of the electrodes. It is recommended to apply sufficient skin preparation to achieve
acceptable electrode impedance. Caution should be exercised during skin preparation
and electrode removal. Excessive preparation and/or sudden removal may lead to skin
reaction and abrasion.
PRECAUTION: In preparing the sites for EMG Electrode placement, patient sensitivity to
disinfecting and sterilizing agents (e.g., alcohol, povidine, etc.), electrode materials, and
adhesive tapes and electrode backings should be considered to prevent skin reactions.
PRECAUTION: Using the provided electrode placement instructions, extreme care should
be taken to confirm that the recording electrodes have been placed on the correct muscle
groups, and on the correct side of the patient, before plugging the EMG Harness into the
Patient Module. Failure to follow these instructions may result in the display of inadequate
information necessary for data interpretation.
PRECAUTION: There may be a noticeable muscle twitch in either or both legs during the
stimulation. This will subside after a few seconds. Do not attempt to restrain the legs to
prevent them from twitching, as this will interfere with the EMG signals.
PRECAUTION: If the patient moves, or is moved, during the course of surgery, electrode
positions may be disturbed. In such instances, electrode positions should be re-examined
to confirm proper location, adequacy of contact, and security of connections. Run
electrode test to affirm adequacy of EMG electrode contact.
PRECAUTION: If the intended level of surgery changes intraoperatively, EMG Recording
Electrode placement may no longer be appropriate for monitoring one or more of the
nerves at or near the operative site. In such an event, the EMG Recording Electrode
placement should be should be altered, commensurate with change.
PRECAUTION: Movement of the patient during stimulation can cause excessive electrical
"noise" and/or false EMG (noise) artifacts.
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