In patients with difficult airways, tracheal extubation is associated with increased risk of adverse events, including need for emergent tracheostomy, anoxic brain injury, hypoxemic cardiac arrest, and death.1 While criteria such as the rapid shallow breathing index help predict likelihood of ventilatory success before extubation, these criteria are fraught with inaccuracies and inconsistencies and are inexact in predicting extubation failure. Furthermore, they do not account for alterations in the airway status, new-onset hemodynamic instability, or other pulmonary issues that may arise postextubation. In its role as a reintubation conduit while maintaining continuous access to the airway, an airway exchange catheter (AEC) has been shown to be a useful adjunct during trials of extubation in patients with difficult airways. By providing a rail for reintubation and a conduit for oxygenation, it diminishes the risk of hypoxemia, severe bradycardia with hypotension, multiple reintubation attempts, and need for airway rescue device use.2–6 Use of an AEC has been recommended by some authors as routine practice for patients who are considered “at-risk” for extubation failure.7,8 However, with the exception of 1 study,9 little has been published on the use of AEC-assisted extubation in pediatric patients. Further, no reports exist regarding extended end-tidal carbon dioxide (Etco2) monitoring via the AEC lumen for assessing continued airway access during the extubation time period. Therefore, we report a case illustrating the value of continuous airway access via the AEC coupled with extended use of Etco2 for ongoing monitoring of its position within the airway.
The patient’s family has provided written consent to publish this case report.
A 30-kg, 19-year-old woman with congenital myopathy, who developed severe midface hypoplasia from years of nasal bilevel positive airway pressure (BiPAP) use, presented for esophagogastroduodenoscopy for abdominal pain, hematochezia, melena, bleeding from her gastrojejunostomy tube, and an acute drop in hemoglobin. She refused tracheostomy under any circumstances. She was presumed to have a full stomach given her suspected upper gastrointestinal bleed. Due to communication barriers and case urgency, an awake intubation attempt was deemed suboptimal. Therefore, midazolam, ketamine, and sevoflurane without muscle relaxation to maintain spontaneous ventilation were administered. Multiple attempts at intubation, including fiberoptic with and without a supraglottic airway conduit and rigid videolaryngoscopy, were unsuccessful due to neck immobility, an extreme anterior angle of her glottis, and rapid desaturation when nasal BiPAP was removed. Ultimately, retrograde intubation was performed using a Cook brand retrograde kit (Cook Medical, Bloomington, IN). The wire was passed through the naris after failure to retrieve it through the mouth. The 11F catheter from the kit was then passed over the wire without fiberoptic assistance, and her airway was secured with a 5.0 internal diameter cuffed nasal RAE endotracheal tube (ETT). Esophagogastroduodenoscopy with cauterization of multiple ulcers was successfully performed. Ten milligrams of dexamethasone was administered to decrease airway edema. After her procedure, she was transported to the pediatric intensive care unit (PICU) intubated for recovery and further care, where 3 additional doses of 8 mg dexamethasone were administered over the following 3 days. Four days later, she was brought to the operating room (OR) for AEC-assisted extubation given her known difficult airway and high risk for failed extubation. Of note, before extubation, her power of attorney and family were updated and the PICU team was prepared for the possibility of terminal sedation, given her ongoing refusal of tracheostomy under any circumstances.
The AEC-assisted extubation was performed as follows (Figure). The head of the bed was elevated 30°. A bronchoscope adapter was placed between the ETT and breathing circuit connector. Using an extra 5.0 internal diameter nasal RAE to measure distance, a 10F suction catheter was marked and advanced just past the tip of the ETT, where 3 mL of 1% lidocaine was sprayed into the trachea to prevent airway reactivity. The suction catheter was removed, and a marked 11F AEC (Cook Medical, Bloomington, IN) was advanced to 2 cm past the tip of the ETT. The patient was suctioned orally. The ETT was removed over the AEC, and BiPAP was immediately applied before securing the AEC. The AEC was then secured on the patient’s cheek using tape and 3M Tegaderm film (3M, Maplewood, MN), ensuring that the distance mark remained at the opening of the naris. The luer-lock Rapi-Fit Adapter (Cook Medical, Bloomington, IN), supplied with the AEC, was attached to the proximal end of the AEC. Next, a continuous Etco2 monitor sampling line was attached, providing continuous monitoring to confirm that AEC migration into the esophagus did not occur. The patient maintained adequate oxygen saturation throughout the procedure. After 15 minutes of observation in the OR, she was transported back to the PICU. The AEC was maintained in situ for 2 days, providing continuous airway access and Etco2 monitoring. The patient remained in the supine position with her head of bed elevated 30°. She tolerated the AEC without additional lidocaine. There was no luminal obstruction due to secretions or need to suction the catheter. After 2 days, the AEC was removed due to minor epistaxis.
This case describes a patient at risk for airway inadequacy due to her underlying myopathy, abnormal anatomy, increased secretions, and possible airway edema due to recent instrumentation. Furthermore, the risk of failed intubation was high given previous difficulty securing an ETT. The patient’s refusal of a surgical airway eliminated another rescue strategy in the case of airway inadequacy and warranted reintubation, thus airway loss after extubation could be a terminal event. The AEC was used to maintain a route for rapid reintubation if needed, which allowed for a safer trial of extubation in this complex patient. Additionally, the adaption of the technique to include continuous Etco2 monitoring provided reassurance of continued airway access. Of note, Etco2 monitoring is not a labeled use for the Cook brand AEC.
The AEC-assisted extubation technique was first described by Drs Bedger and Chang3 in 1987. Its safety and efficacy have been studied in adult and pediatric patients on a limited basis.2–7,9 The AEC can also be used for oxygen insufflation although this technique has several limitations.10 This was not attempted in this case because nasal BiPAP was applied immediately after extubation. AEC utilization can vary from short term (30 minutes to 2 hours) in most elective OR cases to long term (several days) in more complex patients in the intensive care unit. The nasal route was chosen in this case because the ETT had been placed nasally; however, the oral route is also well tolerated. Several features seem to be key in maintaining the catheter until the risk of the need for reintubation subsides: (1) ensuring that the AEC remains in the mid trachea versus migrating to the level of the carina and (2) maintaining the catheter position with an effective securement technique. In our case, we used a clean, identical nasal RAE ETT to mark off an appropriate distance on our AEC. Alternative to this, one could measure to the tip of the in situ ETT using a bronchoscope and mark the appropriate distance on the AEC. Second, we secured the AEC to the patient’s cheek using heavy tape and 3M Tegaderm film, being careful not to create tight curves in the AEC that would have a spring-like effect and encourage AEC migration out of the airway. Excessive flexion or extension of the head and neck were also avoided because these could cause migration of the AEC. Furthermore, the thermolability of the AEC can increase the risk of migration, particularly in the more flimsy 11F size. The position of the AEC was checked during each nursing shift and did not need readjustment. A chest x-ray on postextubation day 2 confirmed the AEC position remained stable in the midtrachea. If Etco2 had disappeared during the time the AEC was in situ, the patient would have been examined for signs of airway obstruction versus migration of the AEC versus obstruction of the AEC lumen. Nasal endoscopy could be used to assess the position of the exchange catheter. If dislodged from the airway, the AEC’s usefulness would have been lost and it would have been removed from the patient. If confirmed to be in position in the airway, a wire could be passed via the lumen of the AEC to clear the lumen if obstructed, taking care not to dislodge the AEC, and reintubation of the patient over the AEC could be attempted if loss of Etco2 continued. Our patient did develop increased secretions and mild epistaxis with the AEC in situ. Although these have not been routinely reported previously with this technique, we believe that they are events to consider.
In summary, we describe the successful use of the AEC-assisted extubation technique with continuous Etco2 monitoring in a pediatric patient over an extended period of time. Advantages and limitations of this technique are summarized in the Table. Consideration for using this technique should be given in the future when managing patients at risk for the need for reintubation in the immediate postoperative period.
Name: Courtney C. Yegian, MD.
Contribution: This author helped gather information, review the literature, and write the manuscript.
Name: Lana M. Volz, MD.
Contribution: This author helped care for the patient and edit the manuscript.
Name: Richard E. Galgon, MD.
Contribution: This author helped care for the patient, review the literature, and edit the manuscript.
This manuscript was handled by: Mark C. Phillips, MD.
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