Chapter 17. Airway Management of a Motorcyclist with a Full-Face Helmet Following a Crash

A 29-year-old male motorcyclist presents to the emergency department (ED) after being involved in a high-speed motor vehicle crash (MVC). The motorcyclist was traveling at approximately 65 km·h−1 (40 miles per hour) when he drove through an intersection and collided with a car. Although damage to the car was minimal, the motorcycle was severely damaged and the patient was found approximately 50 m (160 ft) from the point of impact. The patient's vital signs at the scene were: HR 110 beats per minute (bpm), BP 120/70 mm Hg, RR 24 breaths per minute, and SpO2 93% on room air. Paramedics placed the patient on a spine board and transferred him to the ED. In the ED, he complains of pain in his chest, difficulty breathing, and pain in his legs. He is wearing a nonmodular full-face helmet. His vital signs are found to be HR 120 bpm, BP 110/50 mm Hg, RR 32 breaths per minute, SpO2 89%, and he is becoming confused. There is clinical evidence of a compound fracture of his right femur.

17.2.1 What Are the Initial Steps in the Management of This Patient?

The general principles of trauma care and resuscitation apply to this patient. An initial, rapid survey of the patient's vital functions including his airway, breathing, and circulation (the A-B-Cs) is undertaken.1 Large-bore intravenous access, oxygen, and basic monitoring (pulse oximetry, ECG, and serial blood pressure readings) are instituted quickly. If the helmet cannot be easily or safely removed for the primary survey, supplemental oxygen may be provided by placing an inverted simple face mask through the opening in the helmet. His airway assessment shows that he is wearing a full-face, nonmodular type motorcycle helmet, obscuring his mouth from view. His nose and nares are visible above the line of the face shield portion of the helmet, and his anterior neck is visible and displays normal anatomy. Rapid examination of his chest demonstrates equal air entry bilaterally and his pulses are equal. Although this patient is protecting his airway, is breathing, and has an adequate blood pressure, he may require intervention to control his airway and breathing urgently after completion of the primary survey.

17.2.2 Are There Recommendations in the Advanced Trauma Life Support® Guidelines for the Removal of Helmets Prior to Transport?

There is currently no consensus regarding whether prehospital personnel should routinely remove a patient's helmet prior to transport to hospital. Individual patient factors and coexisting injuries will guide the decision to remove the patient's helmet. If possible, the helmet should remain in place unless emergency airway or respiratory support is needed, in which case the helmet should be carefully removed in a manner that minimizes cervical spine motion. Most helmet removal techniques endorse a two-person approach: one person stabilizes the patient's head from below while another person carefully removes the helmet from above.2 Prehospital personnel should be encouraged to consult with a hospital-based receiving physician if questions regarding patient care exist.

17.2.3 Are There Recommendations in the ATLS® Guidelines for the Removal of Helmets Once the Patient Has Arrived in Hospital?

There is also no consensus on when or how a patient's helmet should be removed once the patient arrives in hospital. If the patient's condition permits, the helmet can remain in place during the trauma assessment to minimize the potential for cervical spine movement. After a careful neurological assessment, and if the patient is in stable condition, removal of the helmet under fluoroscopy may be considered. If the patient's condition necessitates emergency airway or breathing support, the risks of providing airway management with the helmet in place should be carefully weighed against the risks of emergency removal of the helmet. These issues will be discussed later in this chapter.

17.2.4 Following a High-Speed Motorcycle Crash, What Other Injuries Might You Anticipate for This Patient?

Anticipating and identifying coexisting medical conditions in patients is important for practitioners. Alcohol is often a factor in motorcycle crashes and should be suspected in all cases.3 A recent prospective study of 150 patients admitted to the emergency surgical service following a motor vehicle crash showed that 37% were intoxicated with blood alcohol concentration (BAC) greater than or equal to 100 mg·dL−1 or 0.1%4 (1% BAC by volume = 10 mg·mL−1, and the BAC legal limit is between 0.08% and 0.1% depending on the Province or State). Other causes for the crash should also be considered, including cerebrovascular accident, cardiac event, seizure, or intoxication from substances other than alcohol. A focused survey of the patient as suggested by the Advanced Trauma Life Support (ATLS®) guidelines will help to identify injuries that will significantly affect airway management decisions. Airway practitioners should presume that this group of patients will have a full stomach and are at high risk for a cervical spine injury. Also, patients with open-face type helmets are at higher risk of sustaining facial injuries, but these injuries are still possible in patients wearing full-face helmets. A rigorous assessment of the oropharynx, nasal passages, and ears is often difficult in patients wearing helmets and the benefits of a nasotracheal approach to endotracheal intubation should be weighed against the risks of this procedure in this population of patients.

17.3.1 What Types of Helmets Worn by Motorcyclists Are Potentially Problematic for Airway Management?

Motorcycle helmets can be grouped into two categories in the context of airway management: open-face and full-face. Open-face helmets cover the cranium, sometimes cover the ears, but do not cover the neck, chin, mouth, or nose. These features make them less protective to the patient in the event of a crash. There is an increase in the likelihood of serious anterior neck and facial injuries affecting airway anatomy, but concurrently renders airway assessment and intervention more straightforward. Full-face helmets are more protective to patient's face in the event of a crash, but are a major hindrance to airway assessment and intervention since access to the mouth is practically impossible (Figure 17-1). Moreover, removal of full-face helmets can be difficult, resulting in potentially significant cervical spine motion.5,6 A recent study was conducted to evaluate the cervical spinal movement during the removal of a full-face helmet in 10 fresh cadavers with an experimental unstable fractured odontoid. Under fluoroscopy, there was significant movement of C1-C2 during helmet removal and dislocation of C1-C2 in two cases.7 Although the clinical significance of these findings in live patients is unknown, this study suggests that there is a potential risk of spinal cord injury in a patient during the removal of a full-face helmet.

An important variation on the full-face helmet is the modular full-face helmet (Figure 17-2). The design of this helmet allows the movement of the face shield portion of the helmet away from the face. This helmet design allows the effective conversion of a full-face helmet into an open-face configuration, making airway management with the helmet in place more feasible.

17.3.2 Should Helmets Always Be Removed in Order to Provide Airway Management?

Removal of helmets for airway management is case dependent. There is currently no consensus on whether helmets should be routinely removed prior to airway management in trauma patients. There are concerns that cervical spine movement during helmet removal may be significant. Although the evidence of cervical spine movement during helmet removal has been supported by radiographic studies in cadavers, its clinical importance remains unknown. In prehospital care, removal of helmets by paramedics is standard prior to airway management. However, in sports medicine it is currently recommended that emergency medical personnel have the tools to remove face shields in order to provide airway management with the helmet in place.8 Hospital-based airway practitioners should expect situations in which prehospital personnel have deferred definitive airway management until arrival at the hospital and therefore should be prepared for any scenario.

17.3.3 Describe a Systematic Approach to Manage the Airway of a Patient Wearing a Motorcycle Helmet

When a patient is wearing a motorcycle helmet, assessment of their airway should be completed in the standard fashion aiming to assess the feasibility of providing oxygenation and ventilation by: (1) bag-mask, (2) extraglottic device (EGD), (3) tracheal intubation by direct laryngoscopy, or (4) via a surgical airway. The first part of the assessment of a patient wearing a motorcycle helmet is identifying whether the helmet is open- or full-face configuration.

In a patient wearing an open-face helmet, airway management can be performed with the helmet in place and the patient's head can be manually stabilized by an assistant to minimize movement of the head and neck. Bag-mask-ventilation, extraglottic device insertion, tracheal intubation, and surgical airway access are commonly straightforward in this scenario. If the open-face helmet has a visor, it can be removed to optimize line-of-sight during direct laryngoscopy.

In a patient wearing a full-face helmet, the practitioner must now determine whether the helmet is a modular type or not. If it is a modular type full-face helmet, the helmet may be left in place and the face shield portion can be carefully retracted superiorly to expose the face and neck. Once this is done, the airway can be managed with considerations similar to an open-face style helmet. It should be noted that a retracted face shield might obscure the line-of-sight during direct laryngoscopy. Alternative orotracheal intubating devices such as the Trachlight™ lighted-stylet, a video laryngoscope, or a rigid/flexible fiberoptic intubation device are potentially useful.

In a patient wearing a full-face helmet that is not modular, several important issues must be carefully considered. Bag-mask-ventilation and extraglottic device insertion are practically impossible because access to the mouth and face is extremely limited by the face shield. Direct laryngoscopy is also impossible for the same reason. Access to the neck for a surgical airway is often possible and the anatomical landmarks for cricothyrotomy should be carefully assessed. At this juncture, the practitioner should decide: (1) Can the helmet be removed prior to airway management; and (2) Should the helmet be removed prior to airway management? In many cases it may be most appropriate to remove the helmet prior to airway interventions since this provides practitioners with the opportunity to properly assess the patient and optimally expose all relevant anatomy. Although there is no consensus on the proper technique for helmet removal, most authors advocate a two-person technique as described earlier. Some helmets have special mechanisms to facilitate emergency removal. Instructions can sometimes be found written on the sides of the helmet and may prove useful. Once the helmet is removed, oxygenation and ventilation can be provided in the standard fashion.

17.3.4 Should the Endotracheal Intubation Be Performed Awake?

The patient wearing a motorcycle helmet, especially a full-face helmet, has significant predictors of difficult airway management. Bag-mask-ventilation is impossible in patients wearing full-face helmets and is suboptimal in patients wearing open-face helmets because of full-stomach considerations. Laryngoscopy is difficult or impossible with full-face helmets, as is EGD insertion. In light of this, an awake intubation approach should be considered and is a reasonable option in cooperative patients. When possible, an awake look direct laryngoscopy can be a useful adjunct to the airway assessment as well. Unfortunately, awake intubation in this group of patients is challenging because they are often uncooperative and have significant secretions in their airway, limiting the efficacy of topical anesthesia. Practitioners must consider the benefits of an awake technique and be prepared to proceed to an alternative plan.

17.4.1 Describe How You Would Provide Oxygenation and Ventilation in a Situation Where You Cannot Remove a Nonmodular, Full-Face Helmet?

Arguably the most challenging situation for a practitioner is when a patient wearing a full-face helmet needs oxygenation and ventilation but the helmet cannot be removed easily. Many circumstances can make helmet removal difficult or impossible. Examples of such situations include patients with foreign objects penetrating the helmet and embedded in the skull and patients in whom removal of the helmet causes them extreme pain or distress, or individuals trapped in confined spaces where the helmet cannot be removed (eg, race car). A systematic assessment of the airway management options for this patient will show that bag-mask-ventilation is impossible because the helmet's face shield obscures the mouth and chin. Similarly, insertion of an EGD is practically impossible because access to the mouth is also limited. The two remaining options are (1) surgical airway using a cricothyrotomy or (2) nasotracheal intubation. Rapid assessment of the surgical landmarks relevant to cricothyrotomy, either percutaneous or open, is essential since this part of the patient's airway is usually unobstructed by the helmet or face shield. Securing the airway by a nasotracheal route is relatively simple and potentially useful and lifesaving. Airway practitioners familiar with nasotracheal intubation techniques should review the contraindications to this approach, such as evidence of basal skull fracture, prior to proceeding. Blind nasal intubation in a spontaneously breathing patient has a reasonable success rate by experienced practitioners. A recent report showed that blind nasal intubating technique has a 90% success rate for prehospital trauma patients requiring an endotracheal tube.9,10 However, the success of blind nasotracheal intubation is limited by practitioner familiarity. A flexible lightwand, such as the Trachlight™, loaded on a nasotracheal tube can be effectively used to achieve endotracheal intubation in a patient wearing a full-face helmet.11 In this technique, transtracheal illumination using the lightwand indirectly confirms proper placement of the nasotracheal tube.12 If blood is present in the airway, the potential for a false passage in the airway makes a blind technique relatively contraindicated. Using a flexible bronchoscope can be a helpful guide, especially in situations where blind techniques are contraindicated, but its efficacy may be limited by the presence of blood or secretions in the airway. Flexible endoscopic intubation can be performed with the patient awake and the nasopharyngeal mucosa topically anesthetized or with the patient under general anesthesia and muscle relaxed. The risks of each approach should be considered in the context of the patient's comorbidities and the practitioner's familiarity with the techniques.

Airway practitioners are strongly advised to consider a "double set up" plan that includes both a primary intubation approach (eg, a light-guided nasotracheal intubation, flexible bronchoscope, etc) and a secondary back up surgical approach for the patient wearing a full-face helmet that cannot be removed. Since the patient's neck is almost always accessible regardless of the type of helmet worn, a double set up facilitates prompt airway control via a surgical access in case the primary plan is unsuccessful. Two separate equipment trays should be prepared: the first contains all the equipment needed for oral or nasotracheal access; the second tray contains all the instruments needed for a surgical airway. Having a second skilled practitioner available who is familiar with surgical airway access is ideal. Prior to initiating the airway intervention, the patient should be optimally positioned, the neck should be prepped, and the airway management team should agree on clear trigger points that identify when the primary approach has failed and the secondary approach is to be undertaken (ie, surgical airway).

17.4.2 How Do You Perform a Light-Guided Nasotracheal Intubation for This Patient If It Becomes Necessary?

An appropriate size uncut endotracheal tube (ETT) should be used. While it is not possible to warm and soften the ETT in this emergency situation, generous lubrication of the ETT will facilitate nasal intubation and minimize injury. The Trachlight™ (or a flexible lightwand) is prepared as previously described (see Section 11.3.6) with the stiff internal wire stylet removed so that the ETT/Trachlight™ (ETT/TL) unit is pliable and suitable for nasal intubation. Ideally, a vasoconstrictor, for example, xylometazoline hydrochloride (Otrivin) nasal spray (if available and time permits), should be administered prior to the insertion of the ETT/TL through the nostril. Following the placement of the ETT-TL tip into the nasopharynx, it is advanced gently into the glottic opening using the transillumination of the soft tissues of the anterior neck. As it is not possible to perform a jaw lift with the full-face helmet in place, a gentle jaw thrust with minimal neck movement can be performed by an assistant to elevate the tongue and epiglottis. Using the light glow, the tip of the ETT-TL is then guided to the glottic opening. When the tip of the endotracheal tube enters the glottic opening, a bright circumscribed glow can be seen readily just below the thyroid prominence and the ETT-TL unit is then advanced into the trachea.

To demonstrate the effectiveness and safety of light-guided nasotracheal intubation using the Trachlight™ device in patients wearing full-face helmets, we successfully performed this light-guided nasotracheal technique in healthy consented patients undergoing elective oromaxillofacial surgery requiring nasotracheal intubation.11 A BMW System IV motorcycle helmet was used to demonstrate feasibility. With the open-face helmet, ventilation could be achieved easily via a face mask under anesthesia (Figure 17-2). Prior to tracheal intubation, the helmet was in the full-face configuration. Trachlight™ nasotracheal intubation was performed using the technique described earlier. With a gentle jaw thrust, the ETT-TL was then inserted through the nostril and into the nasopharynx. When the tip entered the glottic opening, a bright circumscribed glow was seen in below the thyroid prominence (Figure 17-3). Tracheal intubation was successful in all six patients. The mean time to intubation was 22.0 ± 12.1 seconds. Transient nasal mucosal bleeding was the only observed complication.

Occasionally, the tip of the ETT-TL will repeatedly go posteriorly into the esophagus. To overcome this problem, the tip of the ETT can be easily elevated anteriorly by flexing the neck. However, movement of the neck should be avoided for this patient with a potential cervical spine injury. It is also possible to elevate the tip of the ETT anteriorly and align it with the glottis by inflating the endotracheal tube cuff of the ETT in the hypopharynx with 20 mL of air.13 The tip of the ETT-TL can then be guided by transillumination toward the glottic opening. When the tip enters the glottic opening, a bright circumscribed glow is seen in below the thyroid prominence. At this point, the endotracheal tube cuff should be deflated to allow the advancement of ETT-TL further into the trachea. Following the inflation of the cuff, endotracheal tube placement should be confirmed using auscultation and the presence of end-tidal CO2.

17.4.3 Would Your Approach to Airway Management Change for a Patient Who Is Wearing a Football Helmet or Hockey Helmet?

The approach to a patient who is wearing a different type of protective helmet is similar. Sports helmets can be open-face, full-face, and can have various styles of face shields. Many of these face shields can be easily removed with simple tools, such as a screwdriver. For example, the cage of a football helmet can be easily removed using a cage removal tool that can instantly convert a caged and unmanageable airway into an accessible airway. Current recommendations suggest that injured athletes requiring emergency medical care should have their face shields removed and their helmets left in place for airway management.14,15 This highlights the fact that sports helmets have face shields or cages that are easily removed and takes heed of research suggesting that cervical spine motion is lessened when the helmet is left in place.

Airway management in patients wearing a helmet can present a major challenge to practitioners. The principles of airway management remain the same regardless of whether or not the patient is wearing a helmet; however the type of helmet can significantly impact the options available to practitioners. It is worth remembering that almost all patients wearing a helmet are trauma patients, and so the usual considerations of full stomach, head injury, and cervical spine precautions are applicable. If a patient's airway can be managed with the helmet in place, this is often a safer option if an unstable cervical spine injury is suspected. Removing a helmet prior to airway management is often appropriate to optimize intubating conditions, but should be done carefully. Rarely, situations occur where a patient's helmet cannot be removed but oxygenation and ventilation must be provided, and practitioners must have a plan and the skills to deal with this challenging situation.