INDICATIONS, SAFETY, AND WARNINGS NIM TRIVANTAGE™ EMG ENDOTRACHEAL TUBE

INTENDED USE

The EMG Endotracheal tube is intended for use as a means of providing both an open airway for patient ventilation and for intraoperative monitoring of EMG activity of the laryngeal musculature during surgery when connected to an appropriate EMG monitor.

INDICATIONS FOR USE

The EMG Endotracheal tube is indicated for use where continuous monitoring of the nerves supplying the laryngeal musculature is required during surgical procedures.

CONTRAINDICATIONS

  • The use of paralyzing agents will significantly reduce, if not completely eliminate EMG responses to direct or passive neural stimulation.
  • Do not use the EMG Endotracheal tube in surgical procedures with flammable gases or high temperature generating devices, such as surgical lasers or cauteries inside the airway, to avoid combustion.
  • The EMG Endotracheal tube is not intended for postoperative use. The EMG Endotracheal tube should be removed and replaced with a standard endotracheal tube if ventilation is required beyond the surgical procedure.
  • The EMG Endotracheal tube is not intended for use in infant and neonatal patients.

WARNINGS - EMG tubes

  • Do not excessively bend the EMG tube, particularly at an acute angle (less than 90°). Excessive bending may cause the electrodes to break and become exposed. This may result in degraded monitoring function or completely disable monitoring which will require replacing of the tube and reintubation of the patient.
  • Do not use local anesthetic gels or creams to lubricate the tube or apply topical anesthetic sprays on the vocal cords. The use of neuromuscular blocking agents will significantly reduce, if not completely eliminate, EMG responses to direct or passive neural stimulation. Whenever nerve paralysis is suspected, consult the anesthesiologist.
  • Do not attempt to use an EMG Endotracheal tube without first performing a cuff inflation test. Inflate the cuff with air and visually inspect the cuff for any abnormality. Replace with another EMG Endotracheal tube if any adverse abnormality is found.
  • Cuff deflation or diffusion of a gas or gas mixture (nitrous oxide, oxygen, air) might result in cuff pressure and volume variation. It is recommended to inflate the cuff with the gas used to ventilate the patient to reduce potential effect of such diffusion
  • Do not attempt to manipulate an EMG tube with an inflated cuff after insertion. Manipulating a tube with an inflated cuff may cause partial airway blockage at the tip and/or murphy eye, cuff herniation, tip deflection, and/or injury of the larynx or vocal cords. Ensure that the cuff is fully deflated before any manipulation and confirm that the airway is free of any potential occlusion after repositioning.
  • Do not insert the EMG tube into the patient with cuff inflated
  • Inflation of the cuff by “feel” alone, or by using a measured amount of air is not recommended since resistance is an unreliable guide during inflation. Intracuff pressure should be closely monitored with a pressure measuring device.
  • Do not overinflate the cuff. Ordinarily, the cuff pressure should not exceed 25 cm H2O. Carroll and Greenvik recommend maintaining a seal pressure at or below 25 cm H2O (Carroll, R.G., and Greenvik, A.: “Proper Use of Large Diameter, Large Residual Cuffs.” Critical Care Medicine Vol. 1, No. 3: 153-154, 1973). Overinflation can result in tracheal damage, rupture of the cuff with subsequent deflation, or in cuff distortion which may lead to airway blockage.
  • Minimal Occluding Volume or Minimum Leak techniques should be used in conjunction with an intracuff pressure measuring device in selecting the sealing pressure. Cuff pressure should continue to be monitored thereafter, and any deviation from the selected seal pressure should be investigated and corrected immediately. 
  • Do not attempt to remove an inflated cuff from the trachea. This may result in cuff deformation and/ or injury of the larynx or vocal cords. If resistance is encountered during removal, ensure the cuff is fully deflated
  • Avoid insertion of a suction tube or stylet in a tube that has been distorted by biting or other forces. This may further damage the tube and block the airway.
  • Reposition the EMG tube if it fails the electrode check as improper impedance will impact monitoring performance. If the electrode check continues to fail, replace with another EMG tube as this may be due to inadequate EMG tube electrode continuity.
  • Do not perform Magnetic Resonance Imaging (MRI) on a patient with an intubated EMG Endotracheal tube in place. The effect of MRI on the EMG tubes is unknown.
  • Do not use if sterile package has been opened or is damaged.
  • Avoid false negative responses (failure to evoke a nerve response), which may be caused by:
    • Neuromuscular fatigue from prolonged or repeated exposure to electrical stimuli.
    • Deep anesthesia, which may suppress neuroelectrical activity of the recurrent laryngeal nerve.
    • Insufficient contact between the electrodes and vocal cords due to misplacement or using a tube size that is too small.
    • Displacement during the procedure when rotating, flexing, or extending the patient’s head and neck.
  • Avoid disrupted air supply due to inadequate oxygenation by confirming, monitoring, and maintaining anesthesia gas delivery systems and connections at all times.
  • Avoid inadequate oxygenation and/or tracheobronchial injury, which may be caused by:
    • Excessively bending the tube causing it to kink or retracting the tube which may cause it to crush.
    • Placement in the right main bronchus (deep intubation) by confirming the correct positioning after intubation.
    • A collapsed or blocked tube after performing a test inflation, by inspecting the inner diameter of tube for patency after test inflation
    • Using a non-reinforced EMG tube with anatomically difficult airway.
  • Avoid injury by disposing of the devices in an appropriate sharps or biohazard container.
  • Avoid damage to the trachea, larynx or vocal cords during insertion by inspecting the tube, cuff, and monitoring connections for damage which may occur if the cuff is over inflated during set-up testing.
  • The use of a bite block is essential during trans-cranial Motor Evoked Potentials (TcMEP) procedures. Failure to use a bite block may result in patient injury or damage to the tube.
  • Take care when handling the inflation assembly (inflation valve, pilot balloon, and inflating tube). Do not pull on the assembly, particularly when removing the EMG tube from packaging or during extubation.
  • Do not attempt to re-sterilize or reuse single use disposable devices. Resterilization or reuse may result in device damage and patient injury.

Warnings - EMG monitoring

  • Failure to use a NIM Stimulator Probe may result in not identifying the location or detecting injury to the neuromuscular tissue. During EMG monitoring only, (passive monitoring), neuromuscular tissue may not elicit a response from sharp dissection or all types of manipulation. Use the stimulator probe to confirm location of the neuromuscular tissue.
  • Do not activate the electrosurgical instruments while the stimulator is in contact with tissue or in the surgical field to avoid patient burns.
  • Do not bend the needle electrodes or the electrical integrity may be compromised. Check the electrode integrity after insertion.
  • Do not attempt to straighten bent needles, which may weaken the metal. Improperly placed, weak or bent needles increase the risk of the needle breaking off in the patient.
  • Do not connect electrode leads to any other types of equipment or connections than EMG recording/ monitoring equipment or electrical shock to the patient or user may occur.
  • Avoid injury by using extreme care when handling and cleaning instruments with sharp points or edges.
  • Avoid delivery of current to unintended tissues by using an EMG monitor equipped with active audio and/or visual feedback systems for stimulating.
  • If this equipment is operated in the presence of electromagnetic interference (EMI) or highly sensitive equipment, interference may be encountered and the user should take whatever steps are necessary to eliminate or reduce the source of the interference. Diminished performance may lengthen operating time for anesthetized patient.

 

PRECAUTIONS

  • To reduce the potential of excessive bending of the tube, Medtronic recommends the use of a rigid stylet, or a malleable stylet gradually bent to a Magill curve (140+/-20 mm radius of curvature). Ensure the stylet slides easily in and out of the tube.
  • It is strongly recommended that the clinician(s) have a thorough understanding of and experience with intraoperative EMG Monitoring prior to using the EMG Endotracheal tube in a surgical procedure. This device is not intended to replace the surgeon’s medical judgment or knowledge of neural anatomy and physiology. It is intended to provide the surgeon with an additional tool with which to make better- informed decisions regarding the surgical procedure.
  • It is strongly recommended that the surgeon consult with the attending licensed medical practitioner who will be administering anesthesia prior to the use of EMG monitoring to review EMG monitoring techniques, goals and the effects of the administration of anesthesia on neuromuscular activity.
  • A patient with an implanted electronic device should not be subjected to electrical stimulation unless specialist medical opinion has first been evaluated.
  • Proper sizing, oral intubation and extubation should be in accordance with accepted medical techniques and expert clinical judgment. A tube that is one size larger than standard selection is recommended whenever possible to improve electrode contact with vocal cords. The proper size tube for the patient should be determined prior to intubation by the anesthesia provider and/or surgeon.
  • A spare EMG Endotracheal tube of the correct size should be kept readily available. There is a greater risk of damaging the tube under extreme operating conditions, such as excessive bending, prolonged procedures, and repeated manipulation.
  • A bite block is recommended for use with the EMG Endotracheal tube to prevent damage to the tube.
  • For safe and accurate EMG monitoring, proper handling, insertion and placement of electrodes and probes is critical. Review the appropriate user’s guide for the monitor being used for the procedure.
  • Use Medtronic’s NIM Nerve Integrity Monitor to achieve full functions of the EMG Endotracheal tube. Medtronic cannot support nor guarantee use of the EMG Endotracheal tube with EMG monitors by other manufacturers.
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