This includes either ETI or a surgical airway. Indications for definitive airway strategy include the following:[10
- Presence of apnoea.
- Need for airway protection form aspiration: vomitus, bleeding.
- Unconsciousness: Glasgow Coma Scale <8.
- Severe faciomaxillary fractures.
- Risk for obstruction: neck haematoma, laryngeal/tracheal injury.
- Impending or potential airway compromise: inhalation injury.
- Inability to maintain SpO2> 90% by facemask oxygenation.
Options for achieving ETI may include any one of the following airway aids depending on the situation, device availability and presence of operator with necessary expertise.
- Direct laryngoscopy and tracheal intubation.
- Video laryngoscopy and intubation.
- Fibreoptic tracheal intubation.
- Lightwand-guided tracheal intubation.
- Intubating LMA/C-Trach™-aided tracheal intubation.
- Bullard™-, UpsherScope™- or WuScope™-aided intubation.
- Retrograde technique of tracheal intubation.
- Blind nasal intubation.
Direct rigid laryngoscopy using a straight or a curved blade laryngoscope is still the most successful aid in performing ETI in patients with trauma. This is because we have vast experience with its daily use; vision is not hampered in the presence of blood/secretion/vomitus, and it is robust enough while dealing with an uncooperative/combative patient. It has been erroneously believed that direct conventional laryngoscopy is associated with significant movement of the cervical spine. Cadaveric and studies done on live trauma patients have failed to support this assumption. Today, there is enough evidence that a gentle direct laryngoscopy with MILS is not associated with any aggravation of spinal cord injury.[12
Video laryngoscopes such as GlideScope™
(Verathon, Bothell, Washington), TruviewPCD™
(Truphatek, Israel), McGrath™
Aircraft Medical Ltd., Edinburgh, UK) and others give the ability to view the images on a monitor, thereby providing immediate feedback to an assistant applying external laryngeal manipulation.[14
] In addition, videolaryngoscopic techniques also have a great potential for teaching the art of airway management in trauma patients. But these techniques have their share of disadvantages such as blurring of view in presence of blood and secretions besides being expensive.
Fibre optic tracheal intubation is considered to be the preferred method for intubating a patient with an unstable cervical spine. Least cervical spine movement is associated with fibreoptic tracheal intubation.[15
] In the emergency department, the success rate of this airway aid ranges between 50 and 90%.[16
] However, one should remember that it is most likely to fail in the presence of blood, secretion and vomitus or in an uncooperative, combative patient.
: Laerdal Medical Corp., Wappingers Falls, New York) is a safe, effective, rapid and inexpensive intubating device. Lightwand tracheal intubation is a suitable airway aid in trauma patients where intubation is to be done in the neutral position or with minimal head extension. Its second major advantage is that its success is not significantly impacted by the presence of blood and secretion. However, since this method of intubation is a blind approach, it should be avoided in patients with expanding neck masses or laryngopharyngeal trauma.[14
-aided tracheal intubation has been used in trauma patients for achieving tracheal intubation. They require minimal head and neck movement while placing them into the patient's oropharynx and facilitate ETI as the patient is being simultaneously ventilated. However, Brimacombe et al
. have demonstrated that its use may be associated with significant displacement of the unstable cervical vertebra.[15
] Intubating laryngeal mask airway (LMA) has been noted to cause greater cervical vertebra displacement as compared with conventional orotracheal intubation.[19
] Hence, one should be cautious in its use in patients with cervical injury.
(Circon Corp., Stamford, Connecticut), UpsherScope™
(Mercury Medical, Clearwater, Florida) or WuScope™
(Achi Corp., San Jose, California)-aided tracheal intubation have the advantage of conventional fibreoptic scope. In addition, they are more robust and need less intensive training.[20
] Because of their anatomically curved shape, they are especially suited for patients with cervical spine injury as no head and neck movement is necessary for their use. Cricoid pressure and inline stabilisation of the head and neck does not seem to interfere with the utility of Bullard™
] Like any other fibreoptic laryngoscopes, these are handicapped by their inability to aid visualisation of the larynx in the presence of blood, vomitus or secretions. However, WuScope™ is partly protected from this handicap as its optical system is relatively protected in its tubular blade.[14
Blind nasotracheal intubation, though still a part of ATLS,[10
] has very few indications in trauma patients. One such indication may be limited mouth opening as all other devices detailed above require a mouth opening of at least 2 cm for orotracheal intubation. In such situation, nasotracheal intubation may be attempted if surgical airway is not immediately indicated. One should remember that it should be undertaken only by expert personnel. Contraindications to nasotracheal intubation are significant midface trauma and coagulopathy.[14
Once tracheal intubation has been achieved, it is essential to confirm correct tracheal tube placement. This is done by either visualising the tracheal tube pass through the vocal cords or using other methods such as watching the chest move and auscultating 5 points on the patient's chest; CO2 detector and a chest X-ray. Capnography (continuous CO2 detection with a waveform) is the recommended method now. Only when it is not available, capnometry (single measurement of CO2) should be resorted. Once correctly placed, do not forget to secure the endotracheal tube lest it gets displaced.
Gum elastic bougie is an underutilised airway aid in the setting of trauma airway management. Its advantage lies not only in making a difficult intubation possible when only a portion of laryngeal inlet or epiglottis alone is visualised, but its use is also not affected by the presence of blood and secretion.[10
] All trauma care operators should be satisfied with a Cormack and Lehane's class 2 or 3 view and use a bougie to aid tracheal intubation rather than use force to obtain class 1 view and aggravate cervical injury.
Surgical airway should be resorted when there is severe glottis oedema and/or oropharyngeal haemorrhage, fracture of the larynx and when endotracheal tube fails to be passed through the vocal cords. 1% of trauma patients requiring intubation require a surgical airway.[24
] Surgical airway techniques include cricothyrotomy.[10
] Cricothyrotomy can be performed using the following three techniques:
- A needle using a 12-14 gauge cannula. The cannula, after withdrawing the needle, is connected to 40-50 psi source delivering oxygen at 15 l/minute. Intermittent insufflation, 1 second on and 4 second off, can provide satisfactory jet insufflation.
- A needle airway procedure as above, but where the ventilation is provided by low pressure ventilation.
- “Surgical Airway” where a cuffed tube is inserted into the trachea through the cricothyroid membrane and ventilation is performed through a self-inflating bag or other ventilating technique.
Percutaneous tracheostomy (PCT) is not recommended in the trauma setting.[10
] This is essentially because for performing PCT, one needs to hyperextend the patient's neck. This can have disastrous consequences if the patient has a cervical injury. This procedure can be dangerous and is time-consuming and hence not advocated.