Airway management of patients after a penetrating neck trauma is a major concern, particularly if there is involvement of the occipital-atlantoaxial complex (1,2). Airway management should avoid producing or worsening neurological deficits secondary to movements of the cervical spine, this risk being increased by the presence of a foreign body in the spinal canal. A wide range of different intubation techniques has been used in the management of these patients. Orotracheal intubation with manual cervical immobilization is considered an effective means of airway control in the multiple trauma patient at risk of or with spinal cord injury (3). Nasotracheal intubation causes decreased motion of the C5-C6 segment compared with oral intubation techniques (4). Airway maneuvers, such as chin lift and jaw thrust, can narrow the canal of an unstable C1-C2 segment, but no significant differences have been observed between these airway maneuvers, orotracheal and nasal intubation (5).
However, nasotracheal intubation is not without risk [slower procedure, nasopharyngeal bleeding, retropharyngeal perforation, etc. (3)]. Laryngeal mask devices are suitable for the unstable cervical spine because they do not require head and neck movements for insertion. The LMA exerts less pressure against the retropharyngeal mucosa and cervical vertebrae during insertion than the intubation laryngeal mask (ILM), although intubation through the LMA exerts more pressure than intubation through the ILM (6). However, the ILM produces segmentary motion of cervical vertebrae even with manual in-line stabilization in patients with cervical pathology (7). Awake fiberoptic intubation is probably the “gold standard.” However, patient collaboration is crucial, fiberoptic bronchoscopes are not always available at the emergency room, and the technique requires extensive training. In addition, fiberoptic intubation without muscle relaxants carries a potential risk of coughing which may occur during attempts to anesthetize the vocal cords, during insertion and manipulation of fiberoptic bronchoscope, or insertion of the orotracheal tube itself.
The prone position impairs orotracheal intubation by direct laryngoscopy. After induction of anesthesia in the prone position, the jaw and tongue fall anteriorly, making manual ventilation and LMA insertion easier (8). Finally, the prone position also makes it more difficult to administer adequate local anesthesia for fiberoptic intubation.
In case that ventilation through LMA was ineffective, “plan B” was to place an ILM for ventilation, and if ventilation still had not been effective, tracheal intubation through the ILM, guided under fiberscope view (and muscle relaxation), would have been the next step.
Trauma patients must be generally regarded as having full stomachs, even after long periods without ingestion. In this situation, tracheal intubation after a rapid sequence induction of anesthesia is the commonly chosen technique. Moreover, classical LMA is considered a device not able to protect the airway against aspiration. In the case of a full stomach, placing a classical LMA would be a potential high risk for aspiration. The use of the ProSeal™ LMA, or a completely different approach should then be considered. Fortunately, our patient did not eat for more than seven hours before the anesthesia took place, so the risk of aspiration was very small.
Manual immobilization does not completely prevent neck movement during patient transfer. Our main concern was the space relationship between the bit drill and the neck, even more than the neck movement itself. We managed to transfer the patient “en bloc.” In fact, it was a great aid that the patient, being aware of his situation, also helped to keep his neck and head still. Moreover, placing a Philadelphia collar was impossible because the drill was kept in place until surgery began. Furthermore, “halo” placement was not free of risk in this situation, and it would not have prevented the movement of the drill in relation to the neck.
Finally, sevoflurane was the selected anesthetic for induction. Propofol has already demonstrated its usefulness to promote good conditions for LMA insertion, and could have been a good choice for this reason (8). However, our aim was to try to keep spontaneous ventilation as long as possible during the anesthesia induction, so we chose sevoflurane instead of an IV anesthetic.
In this case, the use of an inhaled induction of anesthesia with sevoflurane, the avoidance of muscle relaxants, and the provision of effective ventilation through an LMA inserted in the prone position seemed to offer a satisfactory approach, which minimized anesthetic and cervical injury risks.
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© 2004 International Anesthesia Research Society
8. Ng A, Raitt DG, Smith G. Induction of anesthesia and insertion of a laryngeal mask airway in the prone position for minor surgery. Anesth Analg 2002;94:1194–8.