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The Upside-Down Intubating Laryngeal Mask Airway: A Technique for Cases of Fixed Flexed Neck Deformity

Kumar, Rakesh, MD; Prashast, , MBBS; Anupriya Wadhwa, , DA; Akhtar, S., MD

doi: 10.1097/00000539-200211000-00066
CASE REPORTS: Case Report
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Department of Anesthesiology and Intensive Care, Maulana Azad Medical College and Associated Hospitals, New Delhi, India

Auust 7, 2002.

Address correspondence and reprint requests to Rakesh Kumar, C-334 Saraswati Vihar, Delhi-110 034, India. Address e-mail to rakeshrampal@hotmail.com.

Postburn contracture causing a fixed flexion deformity is usually managed along the awake limb of the difficult airway algorithm (1). The intubating laryngeal mask airway (ILMA) (2) has a rigid, preformed shape, a fixed height, and a long handle, which seem to make it unsuitable for use in cases of fixed flexed neck deformity.

We describe the successful airway management of a patient with extreme fixed flexion of the neck and a reduced interincisor distance. ILMA insertion with a 180° rotation technique, usually described for laryngeal mask airway (LMA) insertion in the pediatric age group (3–6), has been successful and is one possible approach. This case highlights an innovation that might be of use for cases of fixed flexed deformity of the neck with a somewhat reduced mouth opening.

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Case Report

A 20-yr-old 65-kg woman with severe postburn contracture of the neck, chest, and lower face after chemical burns 1 yr previously (Fig. 1, A and B) presented for release of neck contracture and split skin grafting. Her medical history was insignificant. Apart from airway findings, the general physical and systemic examinations were essentially normal.

Figure 1

Figure 1

The contracture included all the structures in the anterior neck and lower part of the face up to the angle of the mouth bilaterally. The nostrils were stretched and narrowed but patent, and the lower lip was everted. The mouth opening was nearly 25 mm, and an oral cavity examination revealed a Mallampati class 4. Her neck was fixed in flexion with only further flexion possible (1–2 cm).

An airway computerized tomograph showed a break and acute angulation in air shadow at the level of the glottis. The trachea was not compressed or deviated. The remainder of the investigations were normal. A good rapport was established with the patient, and written, informed consent was obtained.

In the operating room, after monitoring and IV infusion were commenced, the patient was premedicated with IV midazolam 2 mg and glycopyrrolate 0.2 mg. The airway was prepared with lidocaine viscous gargles, oral 10% lidocaine spray, nasal decongestants, and lidocaine jelly.

A pediatric fiberoptic bronchoscope (FOB) with a No. 6 endotracheal tube (ETT) mounted on it was placed successfully in the trachea through the right nostril. However, the tube could not be advanced over it into the trachea. Insertion of a No. 3 ILMA was attempted next, but without success, because the handle got stuck in the chest. Insertion of a No. 3 LMA, tried next, could not be correctly positioned and had to be removed because the patient became very uncomfortable. The patient was reassured, and the airway repreparation included ultrasonic lidocaine nebulization.

ILMA No. 3 insertion was reattempted with a 180° rotation technique. The ILMA was held such that the machine end and the superior surface of the handle faced cephalad as the mask portion slipped between the upper and lower incisors. Once the mask portion was inside the mouth up to its angulation, it was rotated through 180° (Fig. 2B–D). During the initial introduction of the mask portion of the ILMA, there was a problem in aligning the plane of the mask with the opening of the mouth, which was facing down in our patient (Fig. 1A). Additionally, the portion of the ILMA where the mask and the rigid tube overlap required some force to negotiate the lower incisors because of the reduced interincisor gap. After this initial difficulty, the rest of the insertion was smooth. The trachea was then successfully intubated blindly through the ILMA by using a No. 7 armored tube, and its placement was confirmed by the end-tidal CO2 tracings. General anesthesia was instituted, and the ILMA was removed after the effect of the nondepolarizing muscle relaxant was adequate. The remainder of the anesthetic was uneventful.

Figure 2

Figure 2

To check whether this technique could be applied in other similar cases, we repeated it in two other female patients of similar build, after obtaining their written, informed consent. A fixed flexion of the neck with everted and pulled lower lip was artificially created. In both cases (Fig. 2A), although laryngoscopy (by using a standard handle but different maneuvers) and ILMA by standard technique failed, ILMA could be easily placed by a 180° technique.

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Discussion

Patients such as ours, with a fixed flexion deformity of the neck, present extreme difficulty in securing the airway. A standard laryngoscope cannot be introduced, even when tried side-on or blade-alone first. It may be possible to introduce a laryngoscope with an obtuse angled blade or a short handle, but it is highly unlikely that any part of the glottis will become visible. The fail-safe approach to such patients is to secure the airway with the patient awake. Airway preparation in such patients is totally dependent on topical application of local anesthetic by means of gargles, spray, and nebulization, all of which were used (Fig. 3).

Figure 3

Figure 3

During the preoperative workup of the patient, we kept the nasal FOB and intubation as our main approach for securing the airway. We also had a number of subsidiary approaches: 1) the ILMA and FOB-guided or blind intubation through it; 2) the LMA; 3) oral FOB and intubation; and 4) contracture release under ketamine anesthesia, followed by laryngoscopy intubation/ILMA intubation/LMA.

The failure of FOB-guided placement of the ETT, despite successful tracheal placement of the FOB, has been documented (7), and the suggested remedy includes rotation of the ETT. The probable reasons for failure in our case were the following: 1) the pediatric FOB we were forced to use, because the No. 6 ETT that passed through the patient’s deformed nostrils did not accept an adult FOB, was too thin to act as a good stylet to allow the ETT to negotiate the acute bend at the junction of the laryngopharynx and glottic opening because of extreme neck flexion, and 2) tube rotation to bypass the obstruction in laryngopharynx could be attempted only twice, because patient discomfort made repeated attempts impossible.

The ILMA is a rigid, preformed device, and the minimum distance between the patient’s hard palate and the anteriormost part of the chest and/or neck required for its introduction is equal to the shortest distance between the tip of the mask portion and the machine end (Fig. 4A). This length can be thought of as the hypotenuse between the two limbs of the ILMA, with one limb carrying the handle and the other having the mask (Fig. 5). In case this distance between the hard palate and the anterior chest and/or neck is reduced, the machine end of the ILMA cannot be lowered enough to align the pharyngeal surface of the ILMA with the hard palate. Thus, even when the machine end impinges on the anteriormost part of the chest and/or neck, the tip of the mask portion of the ILMA faces downward and hits the lower incisors or lower gums (Fig. 2A). In the reported case, too, the distance between the patient’s mouth and chest was greatly reduced because of the flexion of the neck. Additionally, the lower lip was everted, but, because of contracture at the angles of the mouth, the upper lip got pulled over the interincisor space when mouth opening was attempted by the patient. The mouth opening thus apparently became smaller and slitlike, facing downward as the patient opened her mouth (Fig. 1A).

Figure 4

Figure 4

Figure 5

Figure 5

Other authors have also found the insertion of ILMA difficult in patients with fixed neck deformity (8), although some have met with success (9). We believe that contracture in the case of Asai and Shingu (9) was less severe and more to one side (the article has only a roentgenogram), rather than all over, as in our case. The very fact that laryngoscopy was possible in their case points to a milder contracture.

The introduction of LMA also failed, as found by other authors when managing patients with fixed flexed neck deformity (10). This is thought to be due to an acute angle between the pharyngeal and oral axes in these patients (10) and to the inability to fully apply the recommended technique of LMA introduction (11).

Our first three options of securing the airway having failed, we prepared rather tentatively to try the next option of oral FOB-guided intubation; this was our first case of such extreme fixed flexion of neck. In the absence of an airway (e.g., Williams, Ovassapian) to assist fiberoptic intubation and prevent the patient from biting the FOB, we had planned to use the London Hospital dental prop, if possible, to hold the patient’s teeth apart. At this time, the idea to use the ILMA in the upside-down manner came, probably inspired by the technique so often used to introduce the oropharyngeal airway and also described for LMA (3–6).

By positioning the ILMA upside down, we were successful (even in simulated cases) because 1) in the upside-down position, the machine end of the ILMA, which was getting stuck in the anterior chest, was shifted to in front of the patient’s nose (Figs. 2B and 4); 2) to align the mask of the ILMA with the pulled-down upper lip, the machine end of the ILMA had to be shifted somewhat caudad, clearing it further off the nose (Fig. 4); 3) our fear of being unable to rotate the ILMA with its bend inside the mouth turned out to be wrong, because the tongue and soft tissues under it were easily compressible in the submandibular space; and 4) once the mask of the ILMA went inside the mouth, it led to an apparent shortening of its external length equal to the distance between the tip of the mask portion and the patient’s incisors. The shortened external length then allowed the ILMA to be rotated back to its final position without getting stuck at the patient’s chest, despite acute flexion (Fig. 2C, D and Fig. 3).

After successful placement of the ILMA, blind passage of the armored tube provided with it is well documented (12). We were ready for the FOB-guided intubation in case the blind passage failed, but that was not needed.

Thus it seems that this upside-down or 180° technique of introducing the ILMA may be a viable alternative for securing the airway and facilitating endotracheal intubation in patients with an extreme flexion neck deformity, even with a limited mouth opening. Similarly, it might be successful in situations where the reduced distance between the hard palate and the anteriormost portion of the chest and/or neck makes access to the airway difficult by other known methods. These situations may be seen in patients with 1) a large growth on the neck, e.g., a huge thyroid swelling, almost level with the chin when the patient lies straight; 2) a very short neck and truncal obesity or large breasts; or 3) bulky dressings on the neck and chest.

The removal of the ILMA was somewhat tricky in our case. It involved a 180° rotation of the ILMA when the stabilizing rod holding the ETT almost impinged on the chest. This rotation could have accidentally pulled out the ETT. In retrospect, it might have been safer to leave the ILMA and the ETT in place, especially because we had already injected the IV bolus dose of vecuronium. However, after repeating the procedure on simulated patients, we realized that accidental extubation can be easily prevented by pushing the ETT an extra 1–2 cm inside the trachea to compensate for the tug during rotation of the ILMA and by keeping the stabilizing rod still, maintaining gentle downward pressure, until the ETT has been gripped as it reappears under the rotated mask.

Finally, it must also be understood that this approach cannot be applied when 1) the mouth opening is very small (say, <2 cm), 2) there is an intraoral mass, or 3) the submandibular space is noncompliant and prevents the tongue from lodging there during the rotation of the ILMA inside the oral cavity (e.g., in postradiotherapy cases with fibrosis in the submandibular region). In addition, it may be dangerous to use in patients with a large cleft palate (where rotation of the ILMA may be impossible or may damage the palate) or loose incisors with limited mouth opening (where the initial introduction may dislodge the teeth into an inaccessible oral cavity).

We thank C. K. Dua, MD, for departmental support; Sunil Arora, DA, for his ideas while working with the simulated patients; and Shabnam Akram, for her assistance with computer graphics.

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References

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