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Difficult Retrograde Endotracheal Intubation: The Utility of a Pharyngeal Loop

2002; Lippincott Williams & Wilkins; Volume: 94; Issue: 2 Linguagem: Inglês

10.1213/00000539-200202000-00046

1526-7598

Virendra K. Arya, Amitabh Dutta, Pramila Chari, Ramesh Kumar Sharma,

Voice and Speech Disorders

Direct laryngoscopy and tracheal intubation remains the technique of choice to achieve control of the airway. Alternative or additional techniques of airway control are required whenever an airway is deemed difficult because of anatomical and/or technical reasons. The retrograde intubation technique is an important option for gaining airway access from below the vocal cords in such situations (1). We report successful management and the problems encountered while gaining the upper airway by the retrograde catheter method in a patient having bilateral fibrous ankylosis of the temporomandibular joint (TMJ). Case History A cooperative 30-yr-old female patient (52 kg, 154 cm, ASA physical status I) was admitted to the hospital for plastic reconstruction and redo-release of bilateral fibrous ankylosis of TMJ. One year previous, when she underwent release of ankylosis under general anesthesia (GA), control of airway had been extremely difficult. A tracheostomy was performed during local anesthesia as repeated, awake, blind nasal, and retrograde intubation attempts failed. This time, examination of the airway revealed no mouth opening with a minimal gap between the overriding incisors, no movements at both the TMJs, severe retrognathia, and mentothyroid and mentohyoid distances of 3.0 and 2.2 cms respectively (Fig. 1 and 2). Both nares were patent. Neck mobility was normal. Lateral neck radiograph demonstrated a minimal inter-incisor gap, severe retrognathia, prominent gonial notch, submandibular tongue and epigllotic shadow, and long air shadow of extended oropharynx in direct alignment with the esophagus (Fig. 3). There was no history of hoarseness of voice, breathlessness, difficulty in swallowing, or frequent sleep awakenings at night.Figure 1: Frontal view of the patient's face showing severe retrognathia, prominent upper lip, no mouth opening, and reduced mento-hyoid and mento-thyroid distances.Figure 2: Lateral view of the patient's face showing severe retrognathia, inability to open mouth, and reduced mento-hyoid and mento-thyroid distances.Figure 3: Lateral radiograph neck showing minimal inter-incisor gap, severe retrognathia, prominent gonial notch, submandibular tongue and epigllotic shadow, and long air shadow of extended oropharynx in direct alignment with esophagus.In view of airway difficulty during the previous anesthetic, posttracheostomy status, and nonavailability of a fiberoptic bronchoscope, tracheal intubation with awake retrograde technique was planned. After explanation of the procedure, an informed consent was obtained from the patient. Preoperatively, the patient was prepared with aspiration prophylaxis, nasal decongestants, and IM glycopyrrolate. Oral diazepam 5 mg was given 1 h before the procedure. Routine monitoring was applied and bilateral superior laryngeal nerve blocks for the upper airway anesthesia were performed. Topical anesthesia of the nares and nasopharynx was performed with 10% lidocaine spray. The cricothyroid membrane was punctured with a 14-gauge venous cannula and tracheal lumen confirmed by air aspiration. A radio-opaque ureteral guidewire (0.89 mm×150 cm, Terumo-Europe N.V., 3001 Leuven, Belgium) was advanced retrogradely through it and was intended to exit via the nares. This failed repeatedly and resistance to advancement was felt. The guidewire was withdrawn and a 16-gauge epidural catheter was used in its place to prevent airway trauma. It also failed to come out through the patient's nose but could be advanced with ease. On close observation it was visible through the minimal inter-incisor gap as coiled in the oral cavity. It was extracted with the help of a Joseph skin hook (Fig. 4). Thereafter, a Ryle's tube (nasogastric tube) was passed through the right nare and advanced with cricoid pressure to make it coil in the oral cavity and make it possible to remove it orally. This was performed with the intent to retrieve the epidural catheter through the nares with the Ryle's tube. However, the Ryle's tube could not be removed through the inter-incisor gap after multiple attempts and may have gone straightaway into the esophagus on each occasion. We then used a self-made pharyngeal loop device to help extract the Ryle's tube through the mouth. The ureteral guidewire was threaded through a 3-mm uncuffed polyvinyl chloride (PVC) endotracheal tube and doubled up to form a loop (Fig. 4, 5). By pushing the free end of the guidewire, the loop diameter could be altered (Fig. 6). This assembly was gently passed into the oral cavity through the minimal inter-incisor gap. Once inside, the loop was expanded to the maximum to touch the pharyngeal wall circumferentially. The Ryle's tube was again passed via the nare. After advancing it sufficiently, the pharyngeal loop was gently tightened and withdrawn slowly through the inter-incisor gap. With this maneuver we were able to bring out the Ryle's tube orally. Afterwards, the epidural catheter was retrieved nasally with the help of the Ryle's tube. A 7.0-mm PVC endotracheal tube with a soft tip (softened by dipping in lukewarm water for a few minutes) was guided successfully over the tautly held epidural catheter into the trachea. The tracheal end of the epidural catheter was loosened once the tube passed the cords. The cuff of the tube was inflated and the breathing system could then be connected to the endotracheal tube connector with the epidural catheter in place.Figure 4: Shows ureteral guidewire, polyvinyl chloride (PVC) uncuffed endotracheal tube (ETT), and a Joseph skin hook.Figure 5: Polyvinyl chloride endotracheal tube (3.0 mm inner diameter) with a ureteral guidewire passed through it to form a small loop.Figure 6: Formation of large diameter loop after the guidewire is advanced further.Anesthesia was induced and ventilation was controlled using the Bain system. A Ryle's tube was passed into the stomach through the opposite nare. The remaining intra and postoperative period were uneventful. After completion of surgery, the patient's mouth could be opened to 3 cm. The trachea was extubated after reversal of residual neuromuscular blockade and when the patient was fully awake. Discussion Most alternative methods for airway control in difficult situations are applied with the patient awake, before induction of general anesthesia (2). Since its description (3), the retrograde technique of securing the airway has been based on the one described originally by Waters (4). A number of technical and procedural problems may arise using this method. These may include catheter selection (5), site of puncture (6), route of advancement of tracheal tube over catheter (nasal (7) or oral (8)), and attendant complications (1,9). Many refinements have been proposed for this method (5), with the common goal of achieving an uneventful passage of the tracheal tube over the retrograde catheter. Our patient presented with bilateral fibrous ankylosis of the TMJ with no mouth opening, posttracheostomy decannulation status, a history of extreme difficulty in airway control and, most importantly, severe retrognathia that resulted in submandibular tongue leading to an extended oropharynx and a relatively anterior larynx misaligned with the oral and nasopharyngeal airway axes (Fig. 3). All these conditions gave rise to a situation wherein our retrograde catheter was exiting through the mouth instead of the nares and wherein the nasogastric tube intended to come out through the mouth to pull the epidural catheter nasally, repeatedly failed to emerge orally. An epidural catheter was selected to prevent bleeding, as we initially failed to enable the more rigid ureteric guidewire to emerge either orally or nasally and because resistance was felt on advancement. Moreover, an epidural catheter can be kept in situ after the airway is secured, and, by virtue of its flexibility, the tracheal tube can be easily advanced beyond the catheter insertion site without trauma. The difficulty in extracting the epidural catheter nasally, and thereafter a Ryle's tube orally, caused us to improvise the technique with a skin hook and a pharyngeal loop rather than insisting on a rigid guidewire with its inherent drawbacks. The tip of the PVC tube was softened before intubation to make it pass easily beneath the base of the tongue and smoothly enter the trachea at the level of vocal cords. This also prevented intranasal trauma. Our case emphasizes the difficulties encountered while applying the retrograde technique to an acquired anatomical airway problem. Similar problems have been noted in an infant with a congenital hemi-cranio-facial dysmorphology (10). The tendency of a floppy and soft catheter is to exit orally, and with our technique it can be made to come through the nose. We therefore suggest that the modification of the standard retrograde intubation kit with inclusion of a pharyngeal loop assembly may prove decisive in overcoming difficult retrograde intubation situations while providing a broader scope in selecting an appropriate atraumatic soft guidewire.