Failure to establish a definitive airway is a significant cause of death and disability among emergency patients. Oral endotracheal intubation via direct laryngoscopy, increasingly often video-assisted, remains the “gold standard” of airway management. Difficult situations arise in which oral endotracheal intubation is impossible, is contraindicated, or fails. Retrograde guidewire intubation is an alternative airway management technique that should be familiar to those involved with emergency airway management.1
Retrograde intubation was first described in 1960 by Butler and Cirillo.2 In 1963, Waters described insertion of an epidural catheter through a cricothyroid puncture as an alternative means of establishing an airway.3 Powell and Ozdil reported a series of 15 patients in whom retrograde intubation was employed without complications using a plastic catheter rather than an epidural catheter as a guide into the trachea.4 The current technique of retrograde intubation varies little from these original descriptions.
Retrograde intubation represents one of several alternative maneuvers for securing the difficult airway. While mouth tumors, cervical arthritis, and jaw ankylosis represent rare cases of difficult-to-control airways, maxillofacial trauma continues to represent the most common indication for alternative airway management. Retrograde intubation has proven to be an effective method used by Emergency Physicians and prehospital personnel to establish an airway.
Completion times for retrograde intubation vary based on physician experience. Among healthcare professionals who had no prior experience with the technique but who had just completed a mannequin-aided training course, the mean length of time to intubation was 71 ± 4 seconds.1 In a second study involving resident physicians after a brief instruction course, 36 of 40 residents (90%) completed retrograde intubation within 150 seconds, with a mean intubation time of 56 ± 6 seconds.10
The American Society of Anesthesiologists defines a difficult airway as the clinical situation in which a conventionally trained Anesthesiologist experiences difficulty with mask ventilation, difficulty with tracheal intubation, or both.5 Retrograde intubation, among other invasive back-up techniques such as cricothyroidotomy, should be considered in any patient in whom endotracheal intubation may be difficult, is contraindicated, or has failed. It is potentially indicated when airway control is required and less invasive methods have failed. Maxillofacial trauma and cervical spine fractures represent the most common etiologies of a difficult airway.6 In one report of 19 patients with either maxillofacial trauma or fractures of the cervical spine, six had prior, failed orotracheal intubation attempts. In all of these patients, retrograde intubation was successful on the first attempt.6 Jaw ankylosis, cervical arthritis, mouth tumors, and muscular dystrophy represent less common but equally challenging airway situations.4,7
Another clinically important situation arises when a patient presents with impending ventilatory failure. While retrograde intubation is generally a longer procedure than orotracheal intubation, oxygenation and ventilation can be maintained with a bag-valve-mask device during the procedure. It is useful when bleeding obstructs visualization of the glottis.