She complains of headache, nausea, facial pain around the nose and left eye, left-sided chest pain and left hip pain.
She doesn’t complain of neck pain.
- L: Look externally (high risk: large tongue, facial trauma, large incisors)
- E: Evaluate 3-3-2 rule (incisor distance <3, hyoid/mental distance <3, thyroid/hyoid distance <2)
- M: Mallampati score >3
- O: Obstruction in airway
- N: Neck mobility (ie, limited neck mobility).
Systematic review and meta-analysis from 2012 (Glidescope® video-laryngoscopy versus direct laryngoscopy for endotracheal intubation: a systematic review and meta-analysis. Griesdale DE, Liu D, McKinney J, Choi PT. Can J Anaesth. 2012 Jan;59(1)41-52):
- Reviewed RCTs of DL vs VL among “expert” and “non-expert” intubators
- Better visualization, higher first attempt success with VL over DL, benefit seen in “non-expert” group
- Better visualization, higher success with VL, particularly in predicted difficult airways
- Authors state the following:
- “Thus, potential benefits of Glidescope video-laryngoscopy may lie with: 1) use in patients with clinical features indicating difficult laryngoscopy; 2) it being used as a rescue method following failed direct laryngoscopy; or 3) it being used by nonexpert providers”
Non-RCT looking at Difficult Airways in particular (J Emerg Med. 2012 Jun;42(6):629-34. Difficult airway management in the emergency department: GlideScope videolaryngoscopy compared to direct laryngoscopy. Mosier JM, Stolz U, Chiu S, Sakles JC.):
- Evaluation of 772 consecutive ED intubations
- Difficult Airway Predictors (DAPs):
- cervical immobility, obesity, small mandible, large tongue, short neck, blood/vomit in airway, tracheal edema, secretions, facial/neck trauma.
- Primary outcome: 1st-attempt success
- 1st-attempt success rate DL 68%, GVL 78%.
- After controlling for DAPs, GVL more likely to succeed (OR 3.07)
- Presence of blood, small mandible, obesity, large tongue:
- decreasing odds of success with DL
- increasing odds of success of GVL
- DL/intubation unlikely to cause clinically significant movement
- MILS may not immobilize completely anyway
- MILS degrades view
- may cause hypoxia, worsen outcomes in TBI pts
- Pts intubated in ED w/ suspected c-spine injury often have TBI
- but incidence of unstable cervical lesions in this group is low
- Some flex/ext of head unlikely to cause secondary injury, may facilitate prompt intubation in difficult cases
- Trauma patients with confirmed absence of C-spine injury, neck movement measured during MILS
- During intubation under general anesthesia with neuromuscular blockade and manual in-line stabilization, the use of GVL:
- produced better glottic visualization
- but did not significantly decrease movement of the nonpathologic C-spine compared with DL
This 2011 article from Can J Anesth (Robitaille, A. Airway management in the patient with potential cervical spine instability: Continuing Professional Development. Can J. Anesth. (2011) 58:1125-1139)
has a handy chart showing the pros/cons of various airway techniques in the patient with C-spine precautions (though trach light generally not routinely available).
Any recommended guidelines for DL vs VL in a difficult airway with MILS?
There is variability in practice. A lot of DL vs VL selection is personal, based on comfort levels.
The Shock Trauma algorithm, from this article (Stephens CT, Kahntroff S, Dutton RP. The success of emergency endotracheal intubation in trauma patients: a 10-year experience at a major adult trauma referral center. Anesth Analg. 2009 Sep;109(3):866-72.) is as follows:
What Would PHARM Do?
Whenever one is faced with a challenging airway, one should always take into consideration the primacy of oxygenation. In this case where the patient has a high BMI (bariatric), they are at risk for rapid desaturation with respiratory depression/apnea and loss of airway tone. They are also at risk for being difficult to bag-valve-mask ventilate especially with a bloody airway.
Optimal positioning of the airway is limited where there is concern for cervical spine injury. Although manual in line stabilization is the standard practice it is important that anatomic alignment is achieved and De Lorenzo et al (Annals of Emergency Medicine – Volume 28, Issue 3 (1996)) found in an MRI study of healthy adults, that slight flexion equivalent to 2 cm of occiput elevation maximized the spinal canal space at levels C5 and C6, a region of frequent unstable spine injuries while maintaining optimal spinal canal dimensions at other levels. One could theorize that small amounts of neck movement (e.g. +/-4cm occipital elevation in the De Lorenzo study) results in minimal change in spinal canal diameter and is minor compared to the forces and range of movement that would have originally produced any c-spine instability and cord damage. However, even modest neck movement to optimize laryngoscopy is difficult to justify given the lack of evidence of benefit/harm and given safer alternatives such as VL and emergency surgical airway.
Reverse trendelenburg positioning should be used as this will improve the functional residual capacity in the bariatric patient by displacing the weight of the anterior chest wall soft tissues off the thoracic cavity and the intraabdominal contents off the diaphragm.
Ensuring airway patency with nasopharyngeal airways and jaw thrust during induction will assist in the effectiveness of apneic oxygenation by nasal cannulae. Another option might be to insert an endotracheal tube into the hypopharynx as long as there is no concern for intracranial placement! Patients with severe craniofacial injuries or basal skull fractures would make one very cautious about the insertion of any nasal tubes.
Control of airway fluids is important and so early control of the epistaxis in this lady will help with the airway control. Balloon catheters are a rapid way to control bleeding if there is no concern for intracranial misplacement. Anterior packing may also considered.
In determining the approach to intubation, one should strongly consider the modality that one is most familiar with. For most practitioners in this day and age it will be direct laryngoscopy. In the future, this may change.
Direct laryngoscopy (DL) has the advantage where the optics are not inside the airway to become soiled and obscured. Right paraglossal straight blade technique offers the advantage of being able to access the anterior larynx better which is often the situation in c-spine immobilization. Video laryngoscopy offers the advantage of being able to look around the corner to see the glottic opening however soiled optics and tube delivery may be difficulties. Hyperangulated blades like the glidescope allow better view of the anterior airway with increased tube delivery challenges. VL on a direct traditional laryngoscopic blade allows both modalities to be done. Fiberoptic flexible scopes or optical stylets work better for awake intubations with cooperative patients which does not apply to this patient.
The published and anecdotal experience of several Prehospital and Retrieval services internationally in management of the predicted & unpredicted difficult airway in the trauma patient is that direct laryngoscopy with a bougie is the best overall approach for speed and success. The bougie is easier to pass through the cords rapidly if one only has limited time and space to see the glottis.
The bougie SHOULD be used as part of all first attempts and we recommend the bougie first direct laryngoscopy approach in this case.
Minh’s prehospital service in Queensland, Australia ( Royal Flying Doctor Service) has an additional difficult airway device of a Fastrach Intubating Laryngeal Mask and this has been used successfully for blind intubations of trauma patients with blood obscured airways. The French Prehospital airway study by Coombes et al (http://www.ncbi.nlm.nih.gov/pubmed/21169803) supports this approach as well of DL with bougie and Fastrach ILMA as a backup device. The LMA affords limited protection of the airway from fluids, as well as the ability to improve oxygenation/ventilation should hypoxia become a problem.
Other options for oral intubation include manual digital intubation in a completely comatose or relaxed patient where there is no chance of the patient biting the intubator.
In the very difficult traumatic airway where there is no time due to high risk of hypoxia or aspiration, one must achieve oxygenation and airway protection as rapidly as possible. The best method for this is a double setup approach. This is a double provider plan with best attempt of orotracheal intubation and supraglottic airway backup support plus a prepared best attempt via the neck with surgical airway equipment and dedicated scrubbed second provider. Minh discusses this double setup approach and traumatic airways in podcasts 1 and 2 of the Emergency Trauma Management Course podcast (http://etmcourse.com/blog/)
What would be a PHARM approach in this case?
Where there is no pathologic or disrupted airway and the only issue is fluid (blood and vomit), rapid sequence intubation affords your best chance of success with a fully relaxed patient. Reverse trendelenburg positioning and preoxygenation with denitrogenation, oxygenation to SpO2 >>95% and apneic oxygenation would be ongoing.
One would be prepared under double setup to rapidly achieve surgical airway if hypoxia occurs with failure of reoxygenation. Control of the bleeding is ideal but failing that, have two working suction yankauers available.
Using anatomic in line c-spine immobilization and the anterior part of the c-collar removed to allow maximal mouth opening, a DL blade would be used with suction epiglottoscopy and methodical progressive landmark exposure to identify the epiglottis. Once that is done, your best attempts to visualize the posterior cartilages would be done including jaw thrust, external laryngeal manipulation, lifting the epiglottis indirectly by engaging the valleculae and the hyoepiglottic ligament or directly by blade tip.
If unable to keep the airway cleared of blood to visualize, sometimes having your assistant press on the chest allows one to visualize air bubbles of the trachea. Be ready with the bougie in the hypopharynx to intubate.
Ultrasound at the neck may be used to directly see the bougie or tube intubation. Blind confirmation of tracheal intubation may be by tracheal ticks or hold up of the bougie.
Should SpO2 drop to a predetermined critical level (~92%) then the rescue reoxygenation plan should be implemented. For the bloody airway, this would be the intubating LMA approach with simultaneous surgical open cricothyroidotomy to establish a definitive airway by scalpel bougie technique.
Should oxygenation and ventilation be restored then the surgical airway can be on hold while a limited number of further attempts (no more than a total maximum of three) at oral intubation can be tried ensuring that something is done differently to address the encountered difficulties. At this point where you have bought yourself some time (Vortex Green Zone), one must think about the best set of skills, equipment, team, and environment that might be able to achieve definitive airway (e.g Anesthesia, OR, ENT). Hopefully your first DL attempt with suction may have cleared enough blood and fluid to allow VL. If doing VL have suction assistants help you and follow the laryngoscopy on screen.
Once there are three airway misses, the likelihood of success with further attempts is very low and the risk of airway trauma and worsening the ability to ventilate or intubate or disrupting the airway is too great. At this point, should definitive airway be required then an emergency surgical airway should be done.
This post was peer reviewed by Minh Le Cong and Yen Chow. Many thanks to their help/input/approach.
No reference list here – way too many in text to compile a list – see main text!