Successful blind digital intubation with a bougie introducer in a patient with an unexpected difficult airway

A critical aspect of providing safe general anesthesia is the preoperative assessment of the patient's airway. Adequate ventilation and oxygenation are essential for the well-being of the patient. Numerous assessment tools and airway management algorithms have been published to help the anesthesia provider make safe decisions and protect the patient (1–6).

Despite careful evaluation of the airway preoperatively, the provider can be presented with an unanticipated difficult airway to manage. Therefore, after induction of anesthesia and before a paralytic muscle relaxant medication is administered and a potential “point of no return” has been reached, the prudent practitioner again assesses the airway. The airway is tested to ensure that bag-mask ventilation (BMV) is easily attainable before a muscle relaxant is administered. If it is not possible to utilize BMV, the patient is awakened and a secure airway obtained under local anesthesia and sedation with the patient breathing spontaneously.

This case report describes a patient who presented with minimal indicators of a difficult intubation and good BMV after induction of anesthesia. Difficulties were then encountered. Many maneuvers have been described to obtain a successful intubation of the trachea in this situation (7). This report describes another novel technique that might be applied.

CASE REPORT

A healthy nonobese adult man presented for a fluoroscopic genitourinary procedure. Using the 6-D method of airway assessment (8, 9) (Table), the only outlier in his airway examination was decreased extension of the atlanto-occipital joint. Following induction of anesthesia with intravenous propofol, BMV was confirmed. A muscle relaxant, rocuronium, was administered, and direct laryngoscopy and intubation of the trachea were attempted, but these were unsuccessful. Only soft tissue with no identifiable airway anatomy could be seen (Cormack and Lehane grade 4) (8).

Table.

The 6-D method of airway assessment∗

Prior to attempting intubation with an intubating LMA-Fastrach (8), a digital intubation technique in combination with a bougie introducer (SunMed endotracheal tube introducer, SunMed, Largo, FL) was attempted (Figure). Standing at the side of the patient (face to face), the left index and long fingers were inserted into his mouth and along the tongue to a depth that made it possible to digitally identify the epiglottis, the rima glottis, and posterior cartilages. With the fingers pressing the epiglottis against the pharyngeal wall, a bougie was passed along the axis of the long finger (stabilizing it between the index and long finger) and inserted through the glottis, where it elicited tracheal clicking, and was then advanced to a depth of 25 cm from the corner of the lip. The endotracheal tube was then passed over the bougie into the trachea, which was confirmed by capnography. The digital intubation required less than 1 minute.

Figure.

Bougie-assisted digital intubation. (a) After the epiglottis is identified by palpating it with the long finger of the left hand, the bougie is threaded through the glottis and advanced into the trachea. Tracheal clicking elicits tactile vibrations, which confirm tracheal placement of the bougie. (b) The bougie is withdrawn slightly so that the 25-cm mark is at the corner of the lip. The endotracheal tube is threaded over the bougie while the bougie is stabilized in place. (c) With the bougie held in place, the endotracheal tube is turned a quarter turn to the left and then advanced to an appropriate depth. (d) The tube is held in place while the bougie is withdrawn. Tracheal intubation is then confirmed using capnography or an esophageal detector device. Used with permission of J. M. Rich, CRNA, SLAM Airway Training Institute, Rowlett, TX (www.slamairway.com).

DISCUSSION

Digital intubation was recently reviewed by Christodoulou, Murphy, and Hung (10), who stated that it can be used as an acceptable alternative to direct laryngoscopy for tracheal intubation when the standard technique is contraindicated, has failed, or is not possible because of an equipment problem. With the exception of bougie-assisted digital intubation, they describe all the combined techniques used to facilitate digital intubation.

Because of the bougie's smaller diameter and malleability, it is easier to digitally insert through the glottis than is an endotracheal tube. Even when the supraglottic structures are digitally identified, it can be difficult to direct the unassisted tracheal tube through the glottic opening. The use of the bougie in this case made digital intubation rapid and simple. Also, it may have decreased potential airway trauma by obviating the need for further direct laryngoscopy. Persistent and repeated use of direct laryngoscopy during failed intubation may result in airway trauma with resultant morbidity and mortality (11). Bougie-assisted blind digital tracheal intubation may be a viable rescue intubation technique in “can mask-ventilate” patients with difficult laryngoscopy secondary to blood, vomitus, abnormal anatomy, or equipment problems. This technique offers a potential solution for difficult intubation situations occurring in or out of the operating room by any practitioner trained in advanced airway management.

Acknowledgments

I'd like to thank Michael A. E. Ramsay, MD, FRCA, for editorial contributions.