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evoked potential monitoring was performed on a 66-year-old man. During the intraoperative and immedi-ate postoperative periods, the patient remained intu-bated with an 8.0-mm EMG endotracheal tube (ETT)taped at the 22-cm mark at the corner of the mouth.Vital signs were stable throughout the entire postop-erative period. The intubated patient was taken to thepostanesthesia care unit and then to the surgicalintensive care unit. Approximately 12 hours afteroperating room discharge, an anesthesiologist wascalled to evaluate the nurse’s inability to pass a suctioncatheter through the EMG-ETT. The patient was oxy-genating adequately, the EMG-ETT remained at the22-cm mark, and the peak airway pressures were nor-mal. A 10F catheter could not be passed through theEMG-ETT.

Another 12 hours passed, and the anesthesia depart-ment again was called to evaluate the inability to pass asuction catheter. At this time, it was suggested by 2anesthetists that a pulmonary consultation be requestedand that fiberoptic bronchoscopy might be necessary. Inaddition, the chest x-ray from that morning indicatedthe presence of a right lower lobe infiltrate.

Six hours later, the anesthesia department wascalled to stand by during bedside fiberoptic bron-choscopy in the surgical intensive care unit. The pul-monologist was unable to pass a pediatric broncho-scope due to visualization of wires through the middleof the EMG-ETT. The nurse anesthetist found laryn-goscopy difficult because of swelling of laryngeal tis-sue. The pulmonologist fiberoptically intubated thepatient with an 8.0-mm regular ETT with some diffi-culty. The patient’s condition remained stablethroughout the procedure. A malodorous greenishgray sputum covered the EMG-ETT, indicating the

The electromyographic endotracheal tube (EMG-ETT) is a

relatively new tool used to measure integrity of the vocal

cord structures during surgery. We describe a case in which

an EMG-ETT was inserted for the operative period but not

replaced with an ETT during the immediate postoperative

period. Intensive care unit nurses had difficulty suctioning

the EMG-ETT. The patient was not provided the pulmonary

toilet necessary until the EMG-ETT was removed andreplaced with a regular ETT. The purpose of this article is tomake anesthesia providers aware that when mechanicalventilation is required during the postoperative period, theEMG-ETT should be removed and replaced with a regularETT to facilitate pulmonary toilet.

Key words: Endotracheal tube, electromyographic, suctioning.

Case study involving suctioning of anelectromyographic endotracheal tubeEileen Youshock Evanina, CRNA, MSWilkes-Barre, Pennsylvania

Jill L. Hanisak, CRNA, MSAllentown, PA

Anesthesia providers are forever vigilantregarding the structures and nerves of theairway. The external branch of the supe-rior laryngeal nerve supplies motor inner-vation to the cricothyroid membrane.

Injury to this nerve can lead to vocal fatigue andimpaired ability to produce high-frequency vocaltones.1

The major motor nerve of the larynx is the recur-rent laryngeal nerve (RLN).2 Unilateral injury to theRLN is characterized by hoarseness, asymptomaticsequelae, or having a transient voice but does notrequire intervention. Although, bilateral RLN injury israre, aphonia results in adduction of the vocal cordsor airway obstruction, requiring immediate interven-tion.3(p1125) The reported incidence of temporary RLNinjury is 0.4% to 3.9% (mean, 2.2%) and permanentRLN damage, 0% to 3.6% (mean, 1.6%).4 Either typeof injury during surgery can have devastating postop-erative consequences.

Specific types of head and neck surgery makepatients more susceptible to RLN injury. Thyroid andparathyroid surgery, carotid endarterectomy, and ante-rior cervical fusion are examples of surgery in whichRLN damage can occur. A large tumor and previouschemotherapy or radiation around these airway struc-tures can further complicate and make surgery moreprecarious. When deemed necessary, the surgeon mayuse electromyographic (EMG) monitoring during anyprocedure in which there is a potential for damage tothe RLN.

Case reportA suboccipital craniotomy with image-guided biopsyof a midbrain lesion accompanied by somatosensory

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need for ETT suctioning. The patient was extubated afew days later and had no long-term sequelae afterreceiving pulmonary toilet and ventilation. Atelectasiswas resolved within a few days. The EMG-ETT waspartially cut to discover why the suction cathetercould not be passed (Figure 1).

DiscussionNowhere in the product information and instructionsfor the EMG-ETT is the provider instructed to replacethis type of tube at the end of the case with a regularETT. Another concern is that if the patient was difficultto intubate and the EMG-ETT needed to be changed, astiff tube changer cannot be used. The product descrip-tion states, “The tube is fitted with four stainless wireelectrodes (two pairs) which are embedded in the sili-cone of the main shaft of the endotracheal tube andexposed only for a short distance, approximately 30.0mm, slightly superior to the cuff, for contacting thevocal cords.”5 As shown in Figure 2, the wires from theEMG-ETT were entangled, not allowing for passage ofa suction catheter for pulmonary toilet. It is believedthat numerous, frequent suctioning attempts entangledthe wires. (The pediatric fiberoptic scope could not getthrough the entangled wires for suctioning.) The EMG-ETT is not comparable to the anode ETT (Figure 3).With the anode ETT, it is not possible for the wires toenter the middle of the ETT because the wires areembedded in the plastic.

In 1996, the US Food and Drug Administrationapproved the EMG-ETT device for monitoring RLNfunction during surgery.4 This approval was based inpart on research by Eisele4 regarding the EMG-ETTdevice’s use on the first 10 of 31 patients studied.Before the use of the EMG-ETT, 2 needle laryngealelectrodes or paired hook-wire electrodes would beplaced in the true vocal cords to monitor electricalstimulation of the vocal cords.

Figure 4, Figure 5, and Figure 6 show the EMG-ETT and how it works. According to Eisele,4 theadvantage of the EMG-ETT compared with the elec-trodes is “…simplistic in establishing contact and,should tube malposition occur during surgery, inreestablishing electrode contact.” Eisele4 further sug-gests that the incorporation of the electrodes simpli-fies management of the EMG-ETT and keeps the elec-trodes out of the surgeon’s way.

ConclusionAlthough it may be unusual for the wires to becomekinked, making it impossible to provide adequate pul-monary toilet, anesthesia providers must be aware of

this possibility. The purpose of this article was tomake anesthesia providers aware that if mechanicalventilation is required during the postoperativeperiod, the EMG-ETT should be removed andreplaced with a regular ETT to facilitate pulmonarytoilet.

Figure 1. Partially cut open electromyographicendotracheal tube

Figure 2. Entangled wires not allowing suctioning ofthe electromyographic endotracheal tube

Figure 3. Cut anode endotracheal tube

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REFERENCES1. Dackiw APB, Rotstein LE, Clark OH. Computer-assisted evoked

electromyography with stimulating surgical instruments for recur-rent/external laryngeal nerve identification and preservation inthyroid and parathyroid operation. Surgery. 2002;132:1100-1106.

2. Bannister L. Respiratory system. In: Williams PL, Bannister LH,Berry MM, et al. Gray’s Anatomy. 38th ed. Edinburgh, Scotland:Churchill Livingstone; 2002:1628-1652.

3. Schwartz JJ, Rosenbaum SH, Graf GJ. Anesthesia and theendocrine system. In: Barash PG, Cullen BF, Stoelting RK, eds.

Clinical Anesthesia. 4th ed. Philadelphia, Pa: Lippincott Williams& Wilkins; 2001:1119-1139.

4. Eisele DW. Intraoperative electrophysiologic monitoring of therecurrent laryngeal nerve [candidate thesis]. Laryngoscope.1996;106:443-449.

5. Medtronic. Medtronic XOMED NIM EMG Endotracheal Tube[product insert]. Minneapolis, Minn: Medtronic; 2000.

AUTHORSEileen Youshock Evanina, CRNA, MS, is program director, WyomingValley Health Care System/University of Scranton School of NurseAnesthesia, Wilkes-Barre, Pa. She is a doctoral candidate in Theory andResearch Development at New York University, New York, NY.

Jill L. Hanisak, CRNA, MS, is a practicing CRNA at Lehigh ValleyHospital and Health Care Network Anesthesia Services, Allentown, Pa.

Figure 4. Electromyographic endotracheal tube withelectrodes

(Reprinted with permission from Eisele.4

)

Figure 5. Paired electrodes above electromyographicendotracheal tube cuff

(Reprinted with permission from Eisele.4

)

Figure 6. Electromyographic endotracheal tube wireelectrodes touching true vocal cords

(Reprinted with permission from Eisele.4

)