Abstract
A young female patient scheduled for orthognathic surgery under general anesthesia encountered obstacles during nasotracheal intubation in which the cuff of the nasal endotracheal tube was linearly lacerated and the tube tip impacted against the retropharyngeal wall. Repeated episodes of the event happened rendering the intubation unsuccessful. A technique using modified glove fingers was applied, which successfully protected the cuff from shearing by the sharp nasal crista and redirected the tube tip away from the retropharyngeal wall. It is a simple and applicable technique during nasotracheal intubation to prevent cuff damage and potential retropharyngeal dissection.
Keywords
cuff incompetence; cuff protection; modified glove finger;
1. Introduction
Nasotracheal intubation (NTI) offers the surgeon a clear field of view for oromaxillofacial surgery. However, in patients undergoing oromaxillofacial surgery, NTI is frequently unsuccessful by cuff laceration while the nasoendotracheal tube is navigated through the rigid nasal cavity.1 To protect the cuff form damage during the procedure, a finger cot is utilized to cover the anterior portion of the tracheal tube during the procedure.2 However, the use of a finger cot may decrease the flexibility of the nasotracheal tube while it passes through the nasopharyngeal space, consequently increasing the incidence of retropharyngeal dissection. Here, we present a young, female patient scheduled for orthognathic surgery met an unsuccessful intubation because of linear laceration of the cuff and retropharyngeal dissection. By wrapping the surface of the proximal end of the tracheal tube with modified glove fingers, we were successfully in passing the nasotracheal tube, the nasopharynx, without damaging the cuff.
2. Case report
A 23-year-old (162 cm and 48 kg) female patient was scheduled to undergo bilateral vertical ramus osteotomy surgery under general anesthesia facilitated by NTI. The patient was healthy without systemic disease. Examination showed a Mallapati Class I airway; consequently the right nostril was selected for NTI at the suggestion of the otolaryngologist. A nasal RAE tracheal tube ID 6.5 mm (Mallinckrodt Medical, Athlone, Ireland) was softened by warming and lubricated with 2% lidocaine jelly for easier NTI. Four nasal cotton sticks soaked with 6% cocaine was applied to shrink the turbinate mucosa and block the ethmoid and spheno-palatine nerves. The induction of general anesthesia was made by intravenous fentanyl (2 μg/kg), thiamylal (5 mg/kg) and rocuronium (0.6 mg/kg). The initial attempt at NTI was unsuccessful because the cuff of the nasotracheal tube failed to be fully inflated in spite of the insertion into the trachea without obvious resistance. There was a linear laceration along the cuff of the nasotracheal tube ipsilaterally with the side hole. A new and well-lubricated nasotracheal tube covered with finger cot was tried in the second attempt. Unfortunately, with this approach not only the tube tip still went astray in the nasopharyngeal space but also the cuff developed a laceration similar to what was observed on the first tube. In the third attempt, to avoid cuff laceration and redirect the nasotracheal tube tip through the nasopharyngeal space, a technique using two modified glove fingers was applied to cover the anterior part of nasotracheal tube for protection (Fig. 1). When we advanced the well-lubricated nasotracheal tube assembly, we met with resistance in nasopharyngeal space. To overcome this, we pulled the modified glove fingers tightly and tilted the tube tip upwards and simultaneously advanced the nasotracheal tube through the nasopharynx into the oropharynx (Figs. 2C and 2D; simulation of NTI). In the oropharynx, the glove fingers were removed as follows; an elastic Bougie was placed inside the nasotracheal tube and advanced toward the tube tip. We then stopped tightly pulling of the glove fingers and slightly advanced the Bougie to push the glove fingers away from the tube, leaving the Bougie in place (Fig. 1C). We manipulated the nasotracheal tube with a slightly pulling backward movement of the elastic Bougie, to allow its withdrawal from the nasotracheal tube. We used Magill forceps to remove the glove fingers under direct laryngoscopy through the oral cavity (Fig. 1D). The nasotracheal tube was then advanced into the trachea with an intact cuff. There were no signs of severe bleeding in the nasal and nasopharyngeal cavities. The operation was uneventful and the patient left postanesthesia care unit, as usual.
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3. Discussion
Inability of cuff inflation due to cuff rupture or laceration during the peri-intubation period is not an uncommon event. There is demonstrable evidence that finger cots can prevent laceration or incompetence of the nasotracheal tube cuff.1 However, thickening the nasotracheal tube may decrease the tube flexibility and make the tube tip advance in a straight trajectory through the sharp-angled nasopharyngeal space. To overcome the curvature of this space techniques inclusive of the use of nasogastric tube,3 curved Bougie,4, 5 and digit-assisted NTIs6 are able to help solving the problem. However, the difficulties that our patient encountered were linear laceration of the cuff and blockade of advancement of the tube tip over the retropharyngeal recess during NTI.
In this presentation, modified glove fingers which served as an arrester to cover the anterior part of nasotracheal tube could not only protect the cuff from damage but also provide a shearing force to redirect the tube tip trajectory to prevent retropharyngeal lacerations. It is a simple and applicable technique to use in patients who present with potential problems of cuff damage and retropharyngeal dissection during NTI.
Techniques such as fiber-optic bronchoscope7, 8 or retrograde NTI9, 10 may be used instead of the glove finger technique. However, fiber-optic bronchoscope technique does not protect the cuff nor does it guarantee cuff integrity. Choosing the other nostril for NTI is not a rescuing resort because the anesthetist will inevitably still confront the retropharyngeal recess. The retrograde NTI is a practical solution to avoid cuff damage and retropharyngeal dissection, but it needs a preformed nasotracheal tube that is limited in usefulness. Therefore, NTI performed with glove fingers is a simple and feasible technique.
There are two issues which arise from the technique. First, our patient needed two glove fingers to help the cuff to resist the sharp nasal crista. This leads us to contemplate the following question: does using two or more glove fingers provide better advantage? We considered it to be a correlative relationship; with thicker fingers, broken cuff is proportionally less likely. Nevertheless, further investigations are required to identify the actuality of this hypothesis.
Second, we must consider the difficulties associated with removing a glove finger from the oropharynx. After using a Bougie to push the glove fingers forward and at the same time to pull the tube backward slightly, it is not a problem to remove the glove fingers.
Some limitations in this technique raise a question: might it be more advantageous to use a smaller inner diameter (ID) nasotracheal tube instead of the sizes routinely used for NTI (male 7.0 ID; female 6.5 ID). Such a replacement might increase the airway resistance on ventilation. An experienced anesthesiologist with adequate understanding of shearing force should be skillful enough to perform this technique.
4. Conclusion
Patients with sharp concomitant nasal crista and retropharyngeal recess who are to undergo oromaxillofacial surgery under general anesthesia with NTI are suitable candidates for such a technique. This represents a simple, practical and feasible alternative for NTI.