|ORIGINAL CONTRIBUTION - CLINICS IN ANESTHESIOLOGY
|Year : 2017 | Volume
| Issue : 3 | Page : 169-173
Airway Management in Maxillofacial Injuries: Identifying Clinical Determinants requiring Non-Conventional Strategies
Habib Md Reazaul Karim1, Md Yunus2
1 Department of Anesthesiology, Andaman and Nicobar Islands Institute of Medical Sciences and GB Pant Hospital, Port Blair, India
2 Department of Anesthesiology, Critical Care and Pain Medicine, North Eastern Indira Gandhi Regional Institute of Medical and Health Sciences, Shillong, India
|Date of Web Publication||30-Jan-2018|
Habib Md Reazaul Karim
Department of Anesthesiology, Andaman and Nicobar Islands Institute of Medical Sciences and GB Pant Hospital, Port Blair
Source of Support: None, Conflict of Interest: None
Aim: Airway management in maxillofacial injuries is challenging. Conventionally, the method of securing the airway is using Macintosh laryngoscope to intubate the patients. Knowing the clinical variables associated with the need for nonconventional (nonMacintosh) laryngoscopy will aid in better airway management. The present analysis was aimed to identifying the clinical variables associated with nonconventional tracheal intubation in patients with maxillofacial injury. Materials and Methods: Medical records of maxillofacial injury patients with at least one facial bone fracture who needed tracheal intubation from January 2009 to June 2016 in a teaching institute were screened for data collection. The clinicodemographic parameters, techniques, and instruments used for tracheal intubation were noted. The INSTAT software was used for statistical analysis, and P < 0.05 was considered significant. Results: Seventy-three patients (mean age 27.47 ± 9.92 years; 94.52% male) were analyzed. A total of 61.64% of tracheal intubations required nonconventional techniques [i.e. video laryngoscope (27.4%), fiberoptic bronchoscope (26.03%), tracheostomy (6.85%), and 1.37% retrograde intubation]. Video laryngoscopy was preferred over Macintosh in patients with confirmed/suspected C-spine injury. Mouth opening <2 cm [odds ratio (OR): 7.33], multiple facial bone fracture (OR: 4.80), and concomitant mandible and maxilla fractures (OR: 6.50) were associated with tracheal intubation by nonconventional laryngoscopy (P = 0.01). Conclusion: Multiple facial bone fractures, concomitant mandible and maxilla fracture, and mouth opening <2 cm need tracheal intubation using a technique other than Macintosh laryngoscopy.
Keywords: Airway devices, airway management, craniomaxillofacial injury, intubation, laryngoscopy/instrumentation, trauma
|How to cite this article:|
Karim HM, Yunus M. Airway Management in Maxillofacial Injuries: Identifying Clinical Determinants requiring Non-Conventional Strategies. Astrocyte 2017;4:169-73
|How to cite this URL:|
Karim HM, Yunus M. Airway Management in Maxillofacial Injuries: Identifying Clinical Determinants requiring Non-Conventional Strategies. Astrocyte [serial online] 2017 [cited 2020 Mar 28];4:169-73. Available from: http://www.astrocyte.in/text.asp?2017/4/3/169/224190
| Introduction|| |
Airway management forms the first step of advanced trauma life support as hypoxia is an urgent and serious threat to life. Conventional management includes chin lift, bag-mask ventilation with 100% oxygen, followed by endotracheal intubation using Macintosh direct laryngoscope. However, in patients with maxillofacial injuries,, the presence of mandibular and/or maxillary fractures, restricted mouth opening, bleeding in the naso-oropharynx, edema, associated cervical spine injury, and the agitated state of the patient (due to hypoxia/head injury/intoxication, etc.) make conventional airway management a daunting task even for experienced anesthesiologists. In many such patients, there may be a need for alternative nonconventional methods, e.g. bougies, LMAs, video laryngoscopes (VL), fiberoptic bronchoscope (FOB), and occasionally a surgical airway, e.g. cricothyroidotomy/tracheostomy.
Such patients may be seen at odd hours in the emergency when both the necessary special airway management equipment (e.g. VL, FOB etc.) and skilled experts may not be available. And occasionally, even after a careful airway assessment, the anesthesiologist/intensivist may encounter an unanticipated difficult airway., Thus, looking for the clinical variables associated with the need for nonconventional airway management techniques should help the emergency teams in making the necessary arrangements for equipment and expertise to avoid potentially life threatening situations.
| Materials and Methods|| |
The present retrospective study was conducted after obtaining approval from the Institutional Research Board. Noncomatosed maxillofacial injury patients having at least one facial bone fracture and requiring tracheal intubation for anesthesia and critical care management during the period 2009–2016 were included. Patients with maxillofacial injury who were not having bony facial fractures or who did not require tracheal intubation were excluded. Age, sex, number and site of facial bony fractures, degree of mouth opening, associated cervical injuries, and techniques and instruments used for intubation were noted. Severe trismus was noted when mouth opening was <2 cm. The use/nonuse of muscle relaxant before intubation was also noted. Demographic, airway related, and fracture pattern data were recorded on the number and percentage scale. Association between variables and the need of tracheal intubation by nonconventional laryngoscopy was done by Fisher's exact test using INSTAT software (GraphPad Software Inc., La Jolla, CA, USA), and a P value of <0.05 was considered significant.
| Results|| |
Seventy-eight maxillofacial injury patients met the eligibility criteria. Tracheal intubations for most of the simple mandible fracture cases were tried by conventional Macintosh laryngoscope. In case of failure of the conventional technique, video laryngoscopy was used. However, most of the awake fiberoptic intubations were chosen directly as a predefined airway technique of choice. Out of 78 cases, 5 were excluded as advanced airway management techniques were used for teaching/learning purpose and 73 were analyzed for the study. The mean ± standard deviation (SD) [95% confidence interval (CI)] age of patients was 27.47 ± 9.92 (25.16–29.79) years. Only 4 (5.48%) patients were females, giving a male/female ratio of 17.25:1.
Trachea was intubated using conventional Macintosh laryngoscope in 28 (38.36%) cases, and 61.64% cases required nonconventional laryngoscopy techniques. Video laryngoscopy (27.40%) followed by awake fiberoptic intubation (26.03%) were the two most common nonconventional laryngoscopy techniques [Table 1]. Video laryngoscopy (C-MAC) was preferred over Macintosh laryngoscopy in patients with confirmed or suspected C-spine injury and those having mouth opening <2 cm as a predefined technique; however, the association was not statistically significant [Table 2]. Forty-five (61.64%) of the tracheal intubations were done by nonconventional laryngoscopy techniques [Table 1]. The mean age of the patients who required tracheal intubation by video laryngoscopy was higher than those whose trachea was intubated by Macintosh laryngoscopy (30.2 ± 10.38 versus 23.78 ± 9.67 years, P= 0.033).
|Table 1: Distribution of major facial bone fracture and tracheal intubation-related parameters|
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|Table 2: Results of Fisher's exact test: association between variables and the need of video laryngoscopy over conventional Macintosh laryngoscopy|
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Neither male nor female gender was found to be significantly associated with tracheal intubation by nonconventional laryngoscopy (P = 0.154). Out of the variables assessed as an indication for nonconventional tracheal intubation, statistically significant association (OR) was seen with mouth opening <2 cm (OR: 7.33), multiple facial bone fractures (OR: 4.80), and concomitant mandible and maxilla fractures (OR: 6.50) only [Table 3].
|Table 3: Analysis of variables with Fisher's exact test: Association between variables and the need of non-conventional tracheal intubation|
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While mouth opening <2 cm was inversely correlated with tracheal intubation by conventional Macintosh laryngoscopy and use of muscle relaxants, it was directly related to tracheal intubation by awake fiberoptic bronchoscopy and tracheostomy [Table 4]. On comparing laryngoscopy of any kind with awake fiberoptic as a predefined technique, mouth opening <2 cm, multiple facial bone fractures, and concomitant mandible and maxilla fractures were found to be significantly associated with awake fiberoptic intubation [Table 5].
|Table 4: Association between mouth opening and tracheal intubation technique and muscle relaxant use analyzed by Fisher's exact test|
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|Table 5: Analysis of variables with Fisher's exact test: Association between variables and the need of tracheal intubation by awake fiberoptic versus laryngoscopy|
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| Discussion|| |
Advanced Trauma Life Support (ATLS) of American College of Surgeons gives airway management the first priority in the management of trauma patients. Airway assessment for anticipated difficulty in mask ventilation, tracheal intubation, or both is an integral and unavoidable part for any airway management strategy. Airway management plan, selection of the drugs, equipment, and tracheal intubation techniques depend on the airway assessment findings. The Eastern Association for the Surgery of Trauma (EAST) in its practice management guidelines for emergency tracheal intubation immediately following trauma recommends application of a structured assessment tool (e.g. LEMON Law: Look externally, Evaluate the 3-3-2 rule, Mallampati, Obstruction, Neck mobility) for the purpose, which has been shown to reliably predict difficult airway in the emergency department., Craniomaxillofacial injury/fracture is likely to affect almost all the parameters of LEMON Law, and thus, the possibility of overestimating difficulty and misleading a relatively inexperienced or overenthusiastic anesthetist or emergency physician is possible. Mallampati score/class have also been considered to be invaluable in predicting difficult tracheal intubation in emergency settings. However, as craniomaxillofacial injury and fracture leads to trismus, edema, and even altered mental status and uncooperative patients, it is likely to overestimate difficulty. These in turn may lead to unnecessary invasive or noninvasive interventions and even referrals and delay in management of such patients.
As a perfect airway assessment tool does not exist and unanticipated difficulty is still occasionally encountered, using multiple tests to predict a difficult airway is considered a better predictor than any single test used in isolation. Over the last few years, there have been newer innovations and improvements in the airway management devices and techniques; yet, it has not obviated the apprehensions and difficulties in the tracheal intubation in craniomaxillofacial injury patients. Moreover, which equipment and technique needs to be used and when is also not well defined. Therefore, knowing the clinical variables that predict the need for nonconventional laryngoscopy will be helpful in planning the drugs, equipment, and techniques to be used in these patients, especially in emergency situations.
The present study evaluated gender, fracture, and airway-related variables as a predictor of the need for nonconventional laryngoscopy. Although video laryngoscopy was preferred in patients with mouth opening of <2 cm over conventional Macintosh laryngoscopy, it was not statistically significant (P = 0.794). However, mouth opening <2 cm was strongly associated with tracheal intubation by awake fiberoptic bronchoscopy, tracheostomy, and avoiding use of muscle relaxants. Other significant variables associated with tracheal intubation by nonconventional laryngoscopy were multiple facial bone fractures and combined mandible and maxillary fractures. The present study also underlines the important role of video laryngoscopy in patients with suspected C-spine injury.
Reviewing the quality improvement database of prehospital failed intubation cases, Gaither et al. identified that C-spine immobility, blood or vomitus in the airway, airway edema, facial or neck injury, and obesity are predictors of difficult endotracheal intubation. Our findings are similar with regards to facial injury, edema, multiple facial bone fracture, and limited mouth opening as a predictor of difficult intubation, which in turn favored advanced tracheal intubation techniques. However, we did not find C-spine immobility as a predictor. This difference may be because of the differences in the management scenario (prehospital versus in-hospital) and study objectives (predictors of difficult intubation versus predictors of tracheal intubation by nonconventional laryngoscopy). Moreover, a relatively smaller sample size may also affect this finding.
In the airway management of a craniomaxillofacial injury patient, there is always a fear of losing the airway even with moderate sedation. This fear is more after use of muscle relaxant because it may further exacerbate the fall of tongue, especially in bilateral mandible fracture and with edematous oropharyngeal inlet. EAST practice management guidelines recommend that, when significant difficulty is anticipated, neuromuscular blockade should be used with caution, and airway rescue devices, including surgical airway equipment, should be immediately available. The present study also found similar practice where neuromuscular blocking drugs were rarely used in patients with mouth opening of <2 cm.
The challenge in performing intubation with conventional Macintosh laryngoscopy arises mainly from limited mouth opening, difficulty in visualizing the vocal cords, and confirmed or suspected C-spine injury. These problems are reduced with video laryngoscopy, which explains its increasing use in tracheal intubation of such patients. C-MAC video laryngoscope has been shown to achieve higher success rates for tracheal intubation on the first attempt in patients with predicted difficult airways compared to conventional direct laryngoscopy even in skilled hands. Awake fiberoptic intubation also has its limitations, such as inability to use in situ ations of active oozing of blood, by untrained person, in uncooperative patient and its high cost, and limited availability. These factors lead to video laryngoscopes being preferred over fiberoptic as the first option for tracheal intubation in such patients. However, the fiberoptic bronchoscope is flexible, has integrated suction port, and can be used even in patients with no mouth opening. In the present study, awake fiberoptic intubation was used in 26.03% of the cases, which is similar to the findings of Raval et al., but significantly higher than the findings of Saraswat.,
The limitations of the present study include retrospective data collection and lacking multivariate analysis of risk variables. It was also not possible to analyze the number of attempts required for tracheal intubation by conventional Macintosh and C-MAC video laryngoscope, exact number of failures and switchover to advanced techniques, and Cormack–Lehane views due to the retrospective nature of this study which would have given more insight into the matter. Future large, prospective studies could address these problems.
| Conclusion|| |
Single-site mandible fracture is not a major risk for difficult tracheal intubation but concomitant mandible and maxilla fracture is. Mouth opening <2 cm and multiple facial bone fractures in patients with craniomaxillofacial injury are likely to require nonconventional laryngoscopy. Mouth opening <2 cm is also associated with nonuse of muscle relaxant/preservation of spontaneous ventilation. Knowledge of these variables as predictors for the requirement of nonconventional means of laryngoscopy (video laryngoscopy, awake fibreoptic intubation, tracheostomy, etc.) can lead to better airway management and avoid potential disasters in patients with maxillofacial injuries.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]