Residency · Residency · Oral Maxillofacial Surgery
Airway Management and the Difficult Airway in OMFS
Introduction
Airway management is arguably the most critical skill for the oral and maxillofacial surgeon. OMFS practitioners routinely encounter patients with anatomic distortion from trauma, pathology, congenital anomalies, and infection that can make airway management extraordinarily challenging. A systematic approach to airway assessment and a well-rehearsed difficult airway algorithm are essential.
Airway Assessment
History
Key historical elements include previous intubation difficulties or failed intubations, history of obstructive sleep apnea, snoring, or CPAP use, cervical spine pathology or limited neck mobility, prior head and neck surgery or radiation therapy, and presence of maxillofacial trauma or infection.
Physical Examination
The Mallampati classification (Class I through IV) assesses oropharyngeal visualization, with Class III and IV predicting difficult laryngoscopy. A thyromental distance of less than 6 cm suggests difficult intubation. An inter-incisor distance of less than 3 cm (approximately 2 finger breadths) indicates restricted mouth opening. Limited neck extension reduces the laryngoscopic view. The upper lip bite test, in which inability to bite the upper lip with the lower incisors suggests difficulty, provides additional information. A BMI greater than 35, short thick neck, and large tongue all increase difficulty.
Predictive Tools
The LEMON mnemonic provides a systematic approach: Look externally, Evaluate the 3-3-2 rule, Mallampati, Obstruction, and Neck mobility. No single test reliably predicts a difficult airway, so a combination of assessments should be used.
Basic Airway Management Techniques
Basic techniques include head tilt-chin lift and jaw thrust maneuvers, oropharyngeal airway (OPA) and nasopharyngeal airway (NPA) placement, and bag-valve-mask (BVM) ventilation, with a two-person technique recommended for difficult cases. Supraglottic airway devices (SGA) such as the laryngeal mask airway (LMA) and i-gel serve as rescue devices and conduits for intubation.
Advanced Airway Techniques
| Technique | Primary Indication | Advantages | Limitations |
|---|---|---|---|
| Direct laryngoscopy | Standard intubation | Fast, familiar, widely available | Requires line-of-sight; difficult in anterior airways |
| Video laryngoscopy | Anticipated/unanticipated difficult airway | Improved glottic view (99%), reduced C-spine motion | Requires stylet technique practice; fogging |
| Fiberoptic intubation | Anticipated difficult airway (gold standard) | Awake technique; nasal route for OMFS | Requires cooperation; contraindicated with hemorrhage |
| Submental intubation | Panfacial fractures (nasal + oral contraindicated) | Avoids tracheostomy | Requires floor-of-mouth dissection |
| Cricothyrotomy | Cannot intubate, cannot oxygenate (CICO) | Life-saving; rapid | Emergency only; convert to tracheostomy in 24-72 hr |
| Tracheostomy | Prolonged ventilation, major ablative surgery | Definitive surgical airway | Requires OR; complications (stenosis, hemorrhage) |
Direct Laryngoscopy
The Macintosh blade (curved) is placed in the vallecula and lifts the epiglottis indirectly. The Miller blade (straight) directly lifts the epiglottis and is useful in anterior airways. The Cormack-Lehane grading system (Grade I through IV) documents the laryngoscopic view for future providers.
Video Laryngoscopy
Devices such as the GlideScope, McGrath, and C-MAC provide improved glottic visualization in up to 99% of cases. Video laryngoscopy reduces cervical spine motion compared to direct laryngoscopy but requires practice with the stylet-guided tube delivery technique. It is now considered standard of care for anticipated difficult airways.
Fiberoptic Intubation
Fiberoptic intubation is the gold standard for the anticipated difficult airway. It can be performed awake with topical anesthesia and mild sedation. The nasal route is preferred in OMFS due to surgical access needs. It requires patient cooperation and operator experience and is contraindicated in significant midface hemorrhage or nasal obstruction.
Submental Intubation
Submental intubation is a technique specific to OMFS in which the endotracheal tube is passed through a submental skin incision and floor of mouth. It is indicated when both nasal and oral routes are contraindicated, as in panfacial fractures with skull base involvement, and avoids tracheostomy in select cases.
The Difficult Airway Algorithm
The approach is based on the ASA Difficult Airway Algorithm (updated 2022). Step 1 assesses the likelihood of difficulty with ventilation, intubation, and surgical airway. Step 2 formulates a primary plan (Plan A) and backup plans (Plans B, C, D). Step 3 considers awake intubation if difficulty is predicted. Step 4 follows the cannot-intubate algorithm if unanticipated difficulty arises after induction. Step 5 addresses the cannot intubate, cannot oxygenate (CICO) scenario with an emergency surgical airway (cricothyrotomy).
Surgical Airway
Cricothyrotomy
Cricothyrotomy is an emergency procedure for CICO situations. The cricothyroid membrane between the thyroid and cricoid cartilages is identified. A vertical skin incision is made followed by a horizontal membrane incision. A 6.0 cuffed tracheostomy or endotracheal tube is inserted. The procedure is converted to a formal tracheostomy within 24 to 72 hours.
Tracheostomy
Tracheostomy is an elective surgical airway for prolonged ventilation, severe maxillofacial trauma, or major ablative surgery. It is performed between tracheal rings 2-3 or 3-4. Complications include hemorrhage, pneumothorax, tracheal stenosis, and decannulation.
OMFS-Specific Airway Challenges
Maxillofacial trauma with edema, hemorrhage, and anatomic distortion complicates all airway techniques. Ludwig angina and deep space infections with floor of mouth swelling may preclude oral intubation, making awake fiberoptic intubation or tracheostomy preferred. Pathologic masses of the tongue base, oropharynx, or larynx may cause airway obstruction. Post-orthognathic surgery patients with intermaxillary fixation have limited emergency airway access, requiring wire cutters at the bedside. Pediatric craniofacial patients with conditions such as Treacher Collins and Pierre Robin present with small airways and limited mouth opening.
Clinical Pearls
A thorough airway assessment should be performed before every anesthetic, and a normal airway should never be assumed. Video laryngoscopy has become first-line for many OMFS airway scenarios and should be immediately available. The decision to secure the airway while the patient is awake is the most important decision in difficult airway management. Every OMFS practitioner must be proficient in surgical airway access, as it is the final common pathway in CICO. A dedicated difficult airway cart with a fiberoptic scope, SGAs, bougie, and cricothyrotomy kit should be maintained.
References
- Apfelbaum JL, et al. "2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway." Anesthesiology. 2022;136(1):31-81.
- Krausz AA, El-Naaj IA, Bhatt YM. "Airway Management in Oral and Maxillofacial Surgery." In: Miloro M, et al., eds. Peterson's Principles of Oral and Maxillofacial Surgery. 4th ed. Springer; 2022.
- Law JA, et al. "Canadian Airway Focus Group Updated Consensus-Based Recommendations for Management of the Difficult Airway." Canadian Journal of Anesthesia. 2021;68(3):293-310.
- Hernandez Altamirano F, et al. "Submental Intubation: Indications, Technique, and Outcomes in Maxillofacial Surgery." Journal of Oral and Maxillofacial Surgery. 2020;78(9):1547-1555.