Chapter 23. Retrograde Guidewire Intubation

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.

A less common indication includes retrograde intubation of a difficult airway in a patient being ventilated with a laryngeal mask airway. This indication exists because withdrawal of the laryngeal mask airway over a blindly placed catheter can result in dislodgement of the catheter, necessitating replacement of the laryngeal mask airway.8

The major contraindication to retrograde intubation is the ability to control the airway with less invasive techniques. Other contraindications include an anterior neck mass, infections, or cancerous process overlying the cricothyroid membrane. Trismus, or the inability to open the mouth, is a contraindication to this technique. Apneic patients who cannot be ventilated with a bag-valve-mask device should receive a cricothyroidotomy and not a retrograde guidewire intubation. Those unfamiliar with the equipment and/or technique should not attempt this procedure. While one case report presents the successful use of a mannequin to teach retrograde intubation to emergency caregivers, familiarity with the procedure is required for optimum patient management.1

• 68 to 80 cm spring guidewire with a J tip
• 16 to 18 gauge catheter-over-the-needle (angiocatheter)
• Endotracheal tubes, various sizes
• Sterile saline
• 10 mL syringes
• 18 gauge needles
• Hemostats, 2
• Magill forceps
• Sterile drape
• 20 mL syringe
• Povidone iodine or chlorhexidine solution
• Face mask
• Bag-valve device
• Oxygen source and tubing
• Suction source and tubing
• Yankauer suction catheter
• 1% lidocaine
• 4% viscous lidocaine (optional)
• Spray anesthetic (lidocaine or benzocaine)
• Tape (or a commercially available endotracheal tube holder)

Retrograde guidewire intubation can be performed using a standard commercial retrograde intubation kit (Cook Retrograde Intubation Set, Cook Incorporated, Bloomington, IN). It consists of an 18 gauge needle set, 68 to 80 cm spring guidewire, and an 11 French introducer catheter (Figure 23-1). The remainder of the material must be supplied as listed above.

If time permits, and the patient is aware of pain, anesthetize the airway. Nebulized viscous lidocaine will anesthetize the airway in 15 to 20 minutes. Alternatively, inject 2 mL of 1% lidocaine percutaneously through the cricothyroid membrane and into the trachea.6 This may cause the patient to cough and gag, with the subsequent possibility of aspiration. Lidocaine or benzocaine may be sprayed into the pharynx. An alternative anesthetic method includes a superior laryngeal nerve block.9 Refer to Chapter 21 for details regarding this nerve block.

Clean the patient's neck of any dirt and debris. Identify, by palpation, the hyoid bone, thyroid cartilage, cricoid cartilage, and cricothyroid membrane. Apply povidone iodine to the patient's neck, followed by sterile drapes.

The procedure is relatively simple in theory but difficult to perform “in the heat of battle.”1,10–13 Prepare the equipment. Place the 16 to 18 gauge catheter-over-the-needle onto a 10 mL syringe containing 3 to 5 mL of sterile saline. Select an appropriate size endotracheal tube for the patient. Check the integrity of the cuff. Lubricate the inside and outside of the distal tip of the endotracheal tube liberally. Open the retrograde guidewire kit and/or assemble all equipment. The equipment should be preassembled, prepackaged, sterilized, and stored in an easily accessible site.

Stabilize the patient's larynx with the thumb and middle finger of the nondominant hand (Figure 25-2). Identify the cricothyroid membrane with the index finger of the nondominant hand. Leave the index finger on the cricothyroid membrane. Infiltrate lidocaine subcutaneously over the cricothyroid membrane if the patient is awake to minimize discomfort from the percutaneous catheter insertion. Insert the 16 to 18 gauge catheter-over-the-needle guided along the index finger, at a 20° to 30° angle upward and through the cricothyroid membrane (Figure 23-2A). Although not recommended, some physicians prefer to use the needle without the catheter. The sharp needle within the trachea can cause significant injury when compared to the soft catheter. Care should be taken to puncture the cricothyroid membrane just above the cricoid cartilage to avoid injury to the cricothyroid arteries. The loss of resistance signifies that the needle is in the larynx. Aspirate air through the saline-filled syringe to confirm correct needle placement (Figure 23-2A). Advance the catheter until the hub is against the skin. Remove the needle and syringe, leaving the catheter pointed upward and through the cricothyroid membrane. If this has not already been done and the patient is awake, inject 2 mL of 1% lidocaine through the catheter to anesthetize the airway.

Advance the guidewire through the catheter and into the oropharynx (Figures 23-2B & 23-3). The guidewire may exit the mouth or nose. The preferred site of exit is the mouth, but the nose is acceptable. If it is not visualized, insert a laryngoscope and look for the guidewire. It is often in the oropharynx or hypopharynx. Retrieve it with a Magill forceps. Continue to advance the guidewire through the mouth (or nose) until only 4 to 5 cm of the wire is protruding from the patient's neck. Carefully remove the catheter while firmly holding the guidewire in place. Place a hemostat on the guidewire where it enters the skin of the neck (Figure 23-2C). This will ensure that the tip does not pull through the skin and into the trachea.

If the kit is being used, select the introducer catheter contained in it. Pass the introducer catheter over the guidewire that is exiting the mouth (or nose). Advance the catheter until resistance is met. This signifies that the tip of the introducer catheter is at the inside of the cricothyroid membrane (Figure 23-2C). Advance the well-lubricated endotracheal tube over the introducer and guidewire (Figure 23-2D). Continue to advance the endotracheal tube until resistance is met. The tip of the endotracheal tube should be at the inside of the cricothyroid membrane (Figure 23-2D). While securely holding the endotracheal tube at the patient's mouth, remove the hemostat from the guidewire. Pull on the proximal end of the guidewire until the distal tip is through the skin and just into the endotracheal tube. Simultaneously withdraw the guidewire and introducer catheter while advancing the endotracheal tube into the trachea (Figure 23-2E). Inflate the endotracheal tube cuff and confirm proper placement (i.e., auscultation, detection of end-tidal CO2, fogging in the endotracheal tube, etc.).

A second method can also be used to insert the endotracheal tube. This follows the same technique described above to the point of the guidewire exiting the mouth (or nose), being secured with a hemostat at the neck, and passing the introducer catheter over the guidewire. Remove the hemostat from the guidewire. While securely holding the introducer catheter at the patient's mouth (or nose), remove the guidewire through the mouth (or nose). Advance the introducer catheter an additional 2 to 3 cm into the trachea. Lubricate the endotracheal tube liberally. Place the endotracheal tube over the introducer catheter. While holding the introducer catheter securely, advance the endotracheal tube into the patient's trachea. Remove the introducer catheter. Inflate the endotracheal tube cuff and confirm proper placement (i.e., auscultation, detection of end-tidal CO2, fogging in the endotracheal tube, etc.).

This technique may be performed without a formal retrograde intubation kit as the introducer catheter is not required.7,12,13 This follows the same technique described above to the point of the guidewire exiting the mouth (or nose) and being secured with a hemostat at the neck (Figure 23-2C). Lubricate the endotracheal tube liberally. Insert the guidewire through the Murphy eye and into the endotracheal tube. This allows the distal tip of the endotracheal tube to project approximately 1 cm distal to the site at which the guidewire enters the larynx. As an alternative, some physicians prefer to load the guidewire through the tip of the endotracheal tube (Figure 23-4). Always hold the proximal end of the guidewire to maintain control during the procedure. Advance the endotracheal tube over the guidewire until resistance is felt. The tip of the endotracheal tube should be at the inside of the cricothyroid membrane. Hold the proximal end of the guidewire firmly. Release the hemostat over the neck. Pull the guidewire through the skin and just into the endotracheal tube. Advance the endotracheal tube until it is at 20 to 21 cm at the teeth for an adult female or 22 to 23 cm at the teeth for an adult male. Hold the endotracheal tube securely at the patient's lips. Withdraw the guidewire through the patient's mouth. Inflate the endotracheal tube cuff and confirm proper placement (i.e., auscultation, detection of end-tidal CO2, fogging in the endotracheal tube, etc.).

When the endotracheal tube is advanced over the guidewire until resistance is met, the tip should be situated against the inside of the cricothyroid membrane. It is imperative to determine if the tip of the tube is in the trachea or caught on the epiglottis, arytenoid cartilage, pyriform recess, vallecula, or vocal cords. If concern exists as to the position of the tip, withdraw the endotracheal tube 2 cm, rotate it 90°, and readvance it into the trachea. As an alternative, a laryngoscope or fiberoptic broncho/nasopharyngoscope can be inserted to help visualize the placement of the endotracheal tube.

Another variation involves the use of the guidewire sheath as an introducer catheter.12,13 Shorten the sheath by 3 to 5 cm using sterile scissors. The remainder of the technique is the same as described above. The only drawback to this technique is that the curvature of the sheath must be straightened before use to allow easy threading over the guidewire.

In another description, a central venous catheter is used rather than a guidewire.6 It allows the physician to inject air through the catheter in retrograde fashion to help locate the catheter in the mouth of the severely injured patient with significant intraoral blood or secretions. This technique requires a relatively long central venous catheter. It does allow retrograde intubation without the use of a formal retrograde intubation kit.

Finally, another version uses a lighted stylet attached to the endotracheal tube.14 The lighted stylet acts as a guide to indicate the tube's location. When the tip of the endotracheal tube enters the glottic opening, a bright, circumscribed glow is readily seen in the anterior neck, below the thyroid prominence. This glow acts as an indicator of correct endotracheal tube placement.

When continuous oxygenation is required throughout the procedure, two possibilities exist.12 A T-adapter (1260, Deseret, Sandy, UT) can be connected to the needle hub with its side arm for oxygen insufflation. Alternatively, a swivel adapter with a fiberoptic bronchoscopic cap (1/25/09, Portex, Wilmington, MA) can be interposed between the endotracheal tube and the bag-valve-mask device or anesthesia breathing circuit.

Auscultation of both lungs will confirm proper placement of the endotracheal tube and minimize the risk of intubation into the right mainstem bronchus. End-tidal CO2 has also become part of the postintubation routine. After the procedure is completed, a chest radiograph will confirm the placement of the endotracheal tube tip in relation to the clavicles and carina. Please refer to Chapter 12 for a more complete discussion of the methods to confirm endotracheal intubation.

The patient should receive standard wound care and dressing of the skin at the neck entrance site. Wound checks and infection monitoring should continue as with any other surgical procedure. The risk of skin, tracheal, or pharyngeal infection is minimal if sterile technique was followed. If infection develops, wound evaluation and treatment with appropriate antibiotics is warranted.

Complications of retrograde guidewire intubation include those of standard endotracheal intubation. Complications can occur when the needle traverses the cricothyroid membrane.10 Hypoxia due to prolonged intubation time or incorrect endotracheal tube placement remains an important complication. Drug reactions or side effects secondary to administered medications must always be considered.

Retrograde intubation is associated with additional complications due to use of the guidewire. One case report discusses a patient with a history of retrograde intubation for coronary bypass surgery who experienced a foreign-body sensation and bloody sputum 2 years after the procedure.15 Upon radiographic examination, the patient was found to have a 10 cm segment of guidewire fixed in the soft tissue of the puncture site and extending cephalad 2 cm past the true vocal cords.

In one cadaveric study, numerous complications were noted during 40 cricothyroid punctures. Two punctures (5%) occurred below the cricothyroid membrane. One was between the cricoid cartilage and the first tracheal ring. The other was between the first and second tracheal rings. Four cases (10%) showed minor injuries to the thyroid or cricoid cartilage. Three cases (7.5%) showed injuries to the posterior wall of the larynx, epiglottis, or soft palate. No posterior tracheal perforations were found in this study. The clinical importance of these injuries is unclear given the nature of this postmortem study.

Three technical complications from retrograde guidewire intubation have been identified.10,12 Difficulties inserting the guidewire can be prevented by first aspirating air into a saline-filled syringe to confirm the proper intratracheal needle tip position. Endotracheal intubation over a flexible guidewire necessitates keeping the guidewire taut to minimize the risk of kinking. Unfortunately, this moves the guidewire anteriorly toward the narrowest portion of the glottis and may prevent passage of the endotracheal tube, as the tip can become caught on the epiglottis or the vocal cords. This problem is obviated by the use of the introducer catheter in the retrograde guidewire intubation kit. It lies in the posterior pharynx and glottis and allows for easier passage of the endotracheal tube into the trachea. The tip of the endotracheal tube may flip out of the larynx when the introducer is being removed, because the distance between the vocal cords and the point where the introducer enters and anchors the larynx averages only 1.0 to 1.3 cm in adults.

While complications may occur in association with retrograde intubation, the rate of complications is relatively low. In one study, 20 resident physicians performed retrograde intubation twice each on 40 cadavers.10 In two cases (5%), the wire was fed caudad into the trachea due to improper angling of the needle. The remaining intubations were performed without complications.

Retrograde guidewire intubation requires little operator experience or equipment. Multiple reports suggest that this technique is safe, relatively easy to learn, and routinely successful. All physicians involved in the airway management of critically ill and injured patients should be aware of this technique as a potential method to overcome the challenge of a difficult airway. Within the armamentarium of management techniques for the difficult airway, retrograde guidewire intubation should be given due consideration in any situation in which orotracheal intubation is impossible or contraindicated.

Numerous difficult airway management devices and adjuncts have been invented and marketed. Arguably, the various video-assisted laryngoscopy devices have come to dominate the realm of alternative airway management techniques. The role of retrograde guidewire intubation as a difficult airway management approach has further diminished as a consequence. However, retrograde guidewire intubation remains an easy-to-learn and potentially lifesaving tool in the Emergency Physician's growing airway management armamentarium.