WE describe a unique airway management experience involving the Combitube and intubation over a retrograde-placed wire.
We responded to a trauma alert at our institution for a 62 yr-old (113 kg, 192 cm) man who was involved in a motorcycle accident and sustained a closed-head injury. During transport his level of consciousness deteriorated, and the paramedic crew attempted a rapid sequence induction and tracheal intubation to secure the airway. An experienced flight nurse was unable to visualize vocal cords. After two attempts at direct laryngoscopy the patient began to experience oxygen desaturation and the crew placed a Combitube 37-French SA as a rescue airway (Tyco Healthcare Group, Mansfield, MA).1,2The patient was successfully ventilated via the blue (pharyngeal) lumen, confirming placement of the tip of the Combitube in the proximal esophagus.
On arrival in the emergency department the patient was obtunded and on a backboard. His cervical spine was immobilized with a collar, and he had an oxygen saturation of 100%. Breath sounds were auscultated bilaterally, and the initial end-tidal carbon dioxide measured 30 mmHg with ventilation by Ambu-bag. He was placed on a mechanical ventilator and noted to have a large air leak. Although the pilot balloons on the Combitube remained inflated and firm, gas could be heard escaping from the patient’s mouth during ventilation. This did not resolve with insufflation of more air into the pharyngeal cuff. A resident physician and staff anesthesiologist attempted direct laryngoscopy using a Macintosh #4 blade with inline stabilization of the cervical spine, cricoid pressure, and deflation of the pharyngeal cuff. They were unable to visualize recognizable structures, including the epiglottis. A moderate amount of blood was noted in the pharynx, but suctioning it did not improve the view.
Although oxygen saturation remained at 100%, a more definitive airway was required to provide adequate ventilation. It was thought to be inappropriate to remove the Combitube given multiple failed attempts at direct laryngoscopy. An attempt at fiberoptic intubation was dismissed given the findings of blood in the pharynx. In discussion with the trauma surgical team, we decided to attempt placement of a retrograde wire to achieve tracheal intubation. Surgical staff was present and prepared to intervene with a surgical airway if needed.
The pharyngeal balloon on the Combitube was deflated and ventilation held. A retrograde wire was placed through the cricothyroid membrane using the direct Seldinger technique (Cook Retrograde Intubation Set; Cook Critical Care, Bloomington, Indiana). The wire was advanced until it exited the left naris. A semirigid intubation catheter from the retrograde kit was passed over the wire. A lubricated 7.0-mm ID endotracheal tube was advanced over the wire/catheter assembly and into the trachea. The wire and catheter were removed, the endotracheal tube cuff was inflated, and the patient’s lungs were ventilated. Bilateral breath sounds and positive end-tidal carbon dioxide confirmed correct placement of the endotracheal tube. The Combitube was subsequently removed. It appeared grossly normal and without any obvious defects. The patient subsequently received a tracheostomy to manage his airway and required a prolonged stay in the intensive care unit.
This case underscores several important points. The Combitube is well described as an aid in securing the airway when attempts at conventional intubation and ventilation have failed.3Experience has shown that removing a rescue airway, even if it is not providing optimal ventilation, can lead to a “can’t ventilate, can’t intubate” scenario. However, airway exchange with a Combitube may be difficult. During placement, the Combitube is inserted into the esophagus 95% of the time.3This precludes airway exchange over a wire, bronchoscope, or catheter without special preplacement modifications to the Combitube.4In the minority of cases in which the Combitube is placed in the trachea, airway exchange for an endotracheal tube can proceed using a wire or small diameter airway exchange catheter.
Despite this limitation, techniques for airway exchange with a Combitube in the esophageal location have been described. Gaitini et al. described transnasal passage of an armored endotracheal tube over a fiberoptic bronchoscope with a Combitube in place.5Although similar to our approach of not removing the Combitube, this technique may be limited by the availability of the fiberoptic scope and the presence of blood or mucus in the pharynx that may make visualization difficult. At least two reports demonstrate retrograde intubation via the laryngeal mask airway.6,7Again, this is a similar approach of not removing the rescue device while securing the airway with an endotracheal tube.
The retrograde technique is an accepted method for securing the airway.8,9It may be especially useful in patients with facial trauma or hemorrhage or when manipulation of the cervical spine is either impossible or contraindicated. Many trauma patients have facial or neck injuries and oral blood and some may have prehospital placement of a Combitube. Retrograde intubation and the use of a Combitube may be complimentary in these situations, although further experience with this technique is certainly necessary. Nasotracheal intubation is contraindicated in patients with certain facial injuries or basilar skull fractures, neither of which was suspected in our patient. The inability to intubate the trachea is an indication for a surgical airway,10but in discussion with the surgical trauma team, it was thought that the Combitube was serving both as an airway and a means to decrease the risk of aspiration. Therefore it was thought appropriate to attempt retrograde intubation with a surgical airway as a backup.
We do not know whether advancing the wire into the mouth with a Combitube in place is possible or if it would subsequently pose difficulties with antegrade passage of either the catheter or endotracheal tube. One could hypothesize that the nasal route of the wire may have allowed better alignment and ease of passage of the endotracheal tube. In summary, we have demonstrated that it is possible to perform retrograde intubation without removing an in situ Combitube.