Comprehensive airway management of patients with maxillofacial trauma

Midface Including Le Fort Level Injuries

Le Fort fractures occur at uniform weak areas in the midface often due to blunt impact to the face. Sporting injuries are a common cause of facial trauma; however, use of protective equipment has reduced the number of sports-related injuries. All patients with traumatic injuries should be evaluated using Advanced Trauma Life Support protocol. Le Fort fractures can contribute to airway obstruction, and urgent intubation may be indicated. Surgery is indicated for most displaced Le Fort fractures to restore function and facial harmony. To facilitate reduction, the original occlusive relationship should be restored by placing the patient in MMF.

Airway management in maxillofacial trauma

Airway management of patients with maxillofacial trauma remains a challenging task for an anesthesiologist in the emergency and perioperative settings due to anatomical distortion. Detailed knowledge of maxillofacial and airway anatomy is desired for the correct diagnosis of extent and severity of the injury. Basic principles of advanced trauma life support protocols should be followed while managing such patients. Establishing unobstructed airway remains the top priority while maintaining C-spine immobilization and preventing aspiration. Although multiple options exist for securing the airway, a universal technique of airway management may not be applicable to all the patients. Hence, a high index of suspicion along with timely and skillful management is warranted. In this brief review, issues affecting the airway management in cases of maxillofacial trauma are addressed with the possible uses of a wide range of airway management devices available in emergency and elective scenarios.

Securing the Airway in Maxillofacial Trauma Patients: A Systematic Review of Techniques

Study Design

The present study is a systematic review of the literature.

Objective

The goal of this study is to review our experience and the current literature on airway management techniques in maxillofacial trauma.

Methods

Independent searches of the PubMed and MEDLINE databases were performed from January 1, 2019 to February 1, 2019. Articles from the period of 2008 to 2018 were collected. All studies which described both airway management and maxillofacial trauma using the Boolean method and relevant search term combinations, including "maxillofacial," "trauma," and "airway," were considered.

Results

A total of 452 relevant articles in total were identified. Articles meeting inclusion criteria by abstract review included 68 total articles, of which 16 articles were focused on airway management techniques for maxillofacial trauma in the general population and were deemed appropriate for inclusion in the literature review.

Conclusions

Establishing an effective and stable airway in patients with maxillofacial trauma is of paramount concern. In both the acute setting and during delayed reconstruction, special considerations must be taken when securing a reliable airway in this patient population. The present article provides techniques for securing the airway and algorithms for utilization of these techniques, including both during the initial evaluation and the definitive operative management.

Anesthetic Considerations for Oral, Maxillofacial, and Neck Trauma

Blunt, penetrating trauma to the ear, nose, and throat, and related structures are striking. Injuries may range from simple soft tissue wounds to complex injuries of the face, neck, and brain. Proximity of the cervical spine and airway complicate anesthetic management. A multidisciplinary approach is required. Airway control has highest priority in initial care. Management of airway, breathing, and circulation need to be tailored to the patient. Decisions regarding airway management, ventilation strategies, monitoring, and fluid and blood administration should be based on the patient's condition, clinical setting, and the available personnel, expertise, and equipment.

Vertically unstable fractured mandibular segment with attached genial tubercles as a parameter for difficulty during intubation for general anaesthesia-substantiation with computed tomographic (CT) scan evidence

PURPOSE

To study and evaluate the anatomic alterations in the suprahyoid musculature, the hyoid bone, and the laryngeal inlet in patients with vertically unstable fractured mandibular segment with attached genial tubercles using computer tomography for substantiation of the clinical evidence and hypothesis of difficulty during intubation for general anaesthesia.

MATERIALS AND METHOD

Random sampling methodology was used to enrol patients with mandibular bilateral parasymphysis fracture qualifying for the classification of vertically unstable fractured mandibular segment with attached genial tubercles for group A patients. Patients with unilateral parasymphysis fracture with vertically stable mandibular segment were included in group B. Forty patients with parasymphysis fracture and no other associated facial fracture/injury were evaluated prospectively by comparing their pre-operative computer tomography (CT) images with post-operative CT images taken after the reduction of the fracture. Parameters evaluated were variation in the radiologic anatomy of the laryngeal inlet shape and alteration in the suprahyoid musculature after open reduction and internal fixation of the fracture when compared with pre-operative CT images.

RESULTS

The following were the results/observations from this study among group A patients: (1) The distance between the genial tubercles and the hyoid was found to be reduced. (2) Dorsal bodily movement of the hyoid was observed suggesting loss of anterior hyoid support. (3) The posttraumatic changes in the shape of the laryngeal inlet were observed in cases with vertically unstable bilateral parasymphysis fracture. (4) Restoration of morphology of the laryngeal inlet and anterior-posterior distance between genium and hyoid after reduction.

CONCLUSION

Computer tomographic findings confirm that the displacement of fractured mandible and resultant displacement of the genial musculature have their effect on the laryngeal morphology. These posttraumatic changes in cases with dorsally displaced vertically unstable fractured mandibular segment with attached genial tubercles should be considered as a vital parameter for assessing difficulty during intubation.

Submental Intubation

Acquisition of a secure airway is an essential element of the operative management of maxillofacial trauma. Of the options available, submental intubation is an alternative to tracheostomy. The access should be accomplished via a midline approach rather than lateral through the mylohyoid, an armored endotracheal tube utilized to prevent kinking, and the passage facilitated by use of wound dilators obtained from a percutaneous tracheostomy set.

Management of the airway in maxillofacial surgery: part 1

In part 1 of this review of management of the airway in maxillofacial surgery we discuss preoperative assessment of the airway, and the practical means to deal with difficulties. We review the evidence for videolaryngoscopy and flexible indirect laryngoscopy, together with surgical access to the airway including tracheostomy, cricothyroidotomy, and submental intubation.

Flail Mandible and Immediate Airway Management: Traumatic Detachment of Mandibular Lingual Cortex Results in Obstructive Dyspnea and Severe Odynophagia

Isolated mandibular fractures usually represent themselves as non-life-threatening injuries and are not treated in emergency setting. However, some rare patterns of them may result in airway obstruction as a result of displacement of bony fragments. The authors report a patient of an open comminuted fracture of mandibular symphysis which exhibited an uncommon split pattern with retrogression of lingual cortical plate, and thereby induced glossoptosis, painful deglutition, and obstruction of the upper airway within a few hours. The patient underwent immediate intubation for establishing a definitive airway, followed by open reduction and internal fixation of fracture. Surgical airway management was not needed. Anatomic reduction of the fracture was achieved, by reestablishing the patency of upper airway and resolving the painful deglutition. Patient's occlusion and mouth opening returned to the preinjury status. Timely osteosynthesis surgery offered early relief of patient's signs and symptoms, prevented airway complications and development of traumatic mandibular osteomyelitis, as well as obviated the potential need for surgical airway management. The appropriate management of mandibular fractures placing the airway at risk requires immediate diagnosis based on knowledge of specific clinical and radiographic findings. This case emphasizes that emergency clinicians should be able to distinguish those patients who will need airway securing techniques in emergent or prophylactic context, due to an uncommon fracture pattern of facial skeleton. Moreover, emergency clinicians should be conversant with wiring techniques to achieve stabilization of the mandibular framework and to control the pain, hemorrhage, and airway patency.

Neurosurgical Considerations in Craniofacial Trauma

Spinal and traumatic brain injuries (TBIs) often accompany craniofacial trauma. Neurosurgical considerations can range from initial emergent surgery to conservative management of closed head injuries in patients with craniofacial injuries. This article discusses the most common disorders managed by neurosurgeons in the setting of craniofacial trauma, and reviews the usual timing and setting for various treatments that patients with TBI encounter throughout the course of treatment. It also highlights the consequences of TBI on the timing and planning of craniofacial repairs and the importance of multidisciplinary cooperation to provide comprehensive care to survivors of trauma.

Anterior Submandibular Approach for Transmylohyoid Endotracheal Intubation: A Reappraisal with Prospective Study in 206 Cases of Craniomaxillofacial Fractures

Despite a paradigm shift in anesthesia and trauma airway management, the craniomaxillofacial fracture (CMF) patients continue to pose a challenge. A prospective study was planned between April 2007 and March 2015 to investigate the safety, efficacy, utility, and complications of anterior submandibular approach for transmylohyoid intubation (TMI) in CMFs using an armored endotracheal tube (ETT). Out of 1,207 maxillofacial trauma cases reported, this study recruited 206 patients (152 males and 54 females) aged between 21 and 60 years. No episode of oxygen desaturation was noted intraoperatively. Mean time to perform TMI was 6 ± 2 minutes. The mean transmylohyoid ETT withdrawal time/disconnection time from ventilator was approximately 1.5 minutes. Accidental partial extubation of ETT was noted in two patients (0.97%), and three patients (1.45%) developed abscess formations at anterior submandibular site which were managed by incision and drainage. The anterior submandibular approach for TMI was successfully used and provided stable airway in all elective CMF surgery cases, where oral or nasal intubations were not indicated/feasible and long-term ventilation support was not required. It permitted simultaneous dental occlusion-guided reduction and fixation of all the facial fractures without interference from the tube during the surgery with unhindered maintenance of the anesthesia and airway. The advantages include easy, swift, efficient, and reliable approach with a small learning curve.

Flared sign of flail mandible on computed tomography: an unstable fracture associated with a compromised airway

A mandibular fracture alone rarely causes a life-threatening injury. The aim of this paper was to emphasise the importance of prompt identification of the radiological signs of a flail mandible in a patient with maxillofacial trauma who eventually needed definitive management of her airway.

Management of High-Velocity Injuries of the Head and Neck

Trauma centers must prepare to manage high-velocity injuries resulting from a mass casualty incidents as global terrorism becomes a greater concern and an increasing risk. The most recent conflicts in Iraq and Afghanistan have significantly improved understanding of battlefield trauma and how to appropriately address these injures. This article applies combat surgery experience to civilian situations, outlines the physiology and kinetics of high-velocity injuries, and reviews applicable triage and management strategies.

Can Submandibular Tracheal Intubation Be an Alternative to Tracheotomy During Surgery for Major Maxillofacial Fractures?

PURPOSE

During surgery for major maxillofacial fractures, orotracheal intubation can interfere with some surgical procedures and nasal intubation can be contraindicated or impossible. That is why tracheotomy is presented as a solution, although it carries a relatively high incidence of complications. In this study, the use of submandibular tracheal intubation is basically evaluated as an alternative to tracheotomy in such circumstances.

MATERIALS AND METHODS

This prospective study was performed in patients undergoing surgery for major maxillofacial fractures in which oral intubation and/or nasal intubation have been unsuitable, impossible, or contraindicated. The technique of submandibular intubation was assessed intraoperatively and in the postoperative period. The outcomes and complications are presented.

RESULTS

The study included 26 patients aged between 14 and 57 years. All patients had mandibular fractures, with 19 midface fractures (73.1%), 11 nasal bone fractures (42.3%), 10 zygomatic bone fractures (38.5%), 9 naso-orbito-ethmoidal fractures (34.6%), and 9 frontobasilar fractures (34.6%). The procedure time ranged from 5 to 12 minutes (mean, 7 minutes 4.6 seconds). Delayed extubation was performed in 15 cases (57.7%) in which the tube was left in place for a period ranging from 8 to 50 hours (mean, 30 hours 24 minutes). The technique has proved to be straightforward and satisfactory. A postoperative superficial infection occurred in 2 patients, whereas hypertrophic scars occurred in another 2 patients.

CONCLUSIONS

Submandibular endotracheal intubation is straightforward, safe, and quick to carry out. It can be an alternative to tracheotomy as it allows operative techniques and postoperative airway protection without the risks and side effects of tracheotomy.

Management of Battlefield Injuries to the Skull Base

High velocity skull base injuries on the battlefield are unique in comparison to most civilian sector trauma. With more than 43,000 United States military personnel injuries during Operations Iraqi Freedom (OIF) and Enduring Freedom (OEF), the most recent conflicts in Iraq and Afghanistan have significantly expanded the understanding of the physiology of modern battlefield trauma and how to appropriately address these injuries. The acute care principles of effective triage, airway management, and hemorrhage control in these injuries can be life saving and are reviewed here. Specific injury patterns and battlefield examples are reviewed as well, with a review of some of the lessons learned while providing care in a deployed setting. Utilization of the knowledge learned in Iraq and Afghanistan, which have improved casualty care of deployed service members, can be used both in future military conflicts and in civilian trauma care.

Management and reconstruction of blast wounds of the head and neck

PURPOSE OF REVIEW

The purpose of this review is to highlight recent literature related to the initial management and reconstruction of blast injuries to the head and neck.

RECENT FINDINGS

An increasing percentage of combat-related injuries are caused by blast trauma. Management of blast trauma over the last 10 years has improved understanding of the unique nature of these injuries and the importance of thoughtful management and reconstruction. Blast trauma is associated with an increased need for definitive airway management. As a result, initial triage principles of airway management and hemorrhage control are extremely important in the acute setting. Blast trauma results in high-velocity injuries that can lead to extensive soft tissue damage, which has important implications for reconstruction. Staging reconstruction is an important consideration for more extensive injuries.

SUMMARY

Experience on the battlefield with blast injuries over the last decade has led to efficient triage with focus on hemorrhage and airway control. The lessons learned in Iraq and Afghanistan with the unique physiology of blast trauma have improved the casualty care of service members and can be used both in future military conflicts and in civilian trauma care.

Quest for an Ideal Route of Intubation for Oral and Maxillofacial Surgical Manoeuvres

PURPOSE

The optimal route of intubation that may be planned for different oral and maxillofacial surgical manoeuvres.

MATERIALS AND METHODS

A study was performed on patients who underwent nasal, oral or submental route of intubation for elective oral and maxillofacial surgery under general anaesthesia. The study variables were the anaesthetic and surgeon factors that should be taken into consideration before intubation and during surgery, and also algorithms for uneventful surgical procedures. The outcome variables were influence of the 'route of intubation' on 'surgical technique' and vice versa. Overall results were compiled, tabulated and analysed using SPSS version 14.0.

RESULTS

The study sample comprised of 634 patients. It was found that 35 % (204) nasal, 7.5 % (4) oral and 0 % submental route of intubation had statistically significant influence on oral and maxillofacial surgical procedures and vice versa (p < 0.001).

CONCLUSION

This present study concluded that the surgical access and visibility was immensely improved by following the anaesthetic and surgeon factors in conjunction with algorithms described for uneventful oral and maxillofacial surgical procedures. Further, this has also substantially minimized the influence of the 'route of intubation' on 'surgical technique' and vice versa.

Maxillofacial Injury-Not Always a Difficult Airway

The optimal method for securing the airway in injured patients is controversial. Maxillofacial injury has been shown to be a marker for difficult airway management; however, a delay in intubation may result in deterioration of intubating conditions due to further airway bleeding and swelling. Decisions on the timing and method of airway management depend on multiple factors, including patient characteristics, the skill set of the clinicians, and logistical considerations. This report describes the case of a multi-agency response to a motor-vehicle collision in a rural area in Ireland. One young male patient had sustained significant maxillofacial injuries, multiple limb injuries, and had a decreased level of consciousness. Further airway compromise occurred following extrication. Difficult intubation was predicted; however, abnormal jaw mobility from bilateral mandibular fractures enabled easy laryngoscopy and intubation. Although preparation must be made for difficult airway management in the setting of maxillofacial injury, appropriately trained and experienced practitioners should not be deterred from performing early intubation when indicated.

Facing the airway challenges in maxillofacial trauma: A retrospective review of 288 cases at a level i trauma center

BACKGROUND

Maxillofacial trauma is an apt example of a difficult airway. The anesthesiologist faces challenges in their management at every step from airway access to maintenance of anesthesia and extubation and postoperative care.

METHODS

A retrospective study was done of 288 patients undergoing surgery for maxillofacial trauma over a period of five years. Demographic data, detailed airway assessment and the method of airway access were noted. Trauma scores, mechanism of injury, duration of hospital stay, requirement of ventilator support were also recorded. Complications encountered during perioperative anaesthetic management were noted.

RESULTS

259 (89.93%) of the patients were male and 188 (62.85%) were in the 21-40 year range. 97.57% of the cases were operated electively. 206 (71.53%) patients were injured in motor vehicular accidents. 175 (60.76%) had other associated injuries. Mean Glasgow coma scale score (GCS), injury severity score (ISS) and revised trauma score (RTS) were 14.18, 14.8 and 12, respectively. Surgery was performed almost nine days following injury. The mean duration of hospitalization was 16 days. ICU admission was required in 22 patients with mean duration of ICU stay being two days. Majority of patients had difficult airway. 240 (83.33%) patients were intubated in the operating room and fibreoptic guided intubation was done in 159 (55.21%) patients. Submental intubation was done in 45 (14.93%) cases.

CONCLUSIONS

Maxillofacial injuries present a complex challenge to the anaesthesiologist. The fibreoptic bronchoscope is the main weapon available in our arsenal. The submental technique scores over the time-honored tracheostomy. Communication between the anaesthesiologist and the surgeon must be given paramount importance.

Intra-Operative Airway Management in Patients with Maxillofacial Trauma having Reduction and Immobilization of Facial Fractures

BACKGROUND

Despite advancements in airway management, treatment of fractures in the maxillofacial region under general anesthesia remains a unique anesthetic challenge. We reviewed the pattern of airway management in patients with maxillofacial fractures and assessed those challenges associated with the different airway management techniques employed.

MATERIALS AND METHODS

The anesthetic chart, theatre and maxillofacial operations records of patients who had reduction and immobilization of various maxillofacial fractures over a 2-year period were reviewed. Information obtained included the patient demographics, mechanisms of injury, types of fractures and details about airway management. Statistical Package for Social Sciences, SPSS version 17.0 was utilized for all data analysis.

RESULTS

Fifty-one patients were recruited during the 2-year study period. Mask ventilation was easy in 80-90% of the patients, 80% had Mallampati three or four, while 4 (7.8%) had laryngoscopy grading of 4. There was no statistically significant difference between the fracture groups in terms of the laryngoscopy grading (P = 0.153) but there was statistical significant difference in the technique of airway management (P = 0.0001). Nasal intubation following direct laryngoscopy was employed in 64.7% of the patients, fiber-optic guided nasal intubation was utilized in only 7.8%. None of the patients had tracheostomy either before or during operative management.

CONCLUSION

Laryngoscopic grading and not adequacy of mouth opening predicted difficult intubation in this group of patients in the immediate preoperative period. Despite the distortions in the anatomy of the upper airway that may result from maxillofacial fractures, nasal intubation following direct laryngoscopy may be possible in many patients with maxillofacial fractures.

Vertically unstable fractured mandibular segment with attached genial tubercles as a parameter for difficulty during intubation for general anaesthesia

PURPOSE

It remains vital for the trauma management team including the anaesthetist and the operating surgeon to assess and evaluate the anticipated difficulty in intubation to secure airway and for administration of anaesthesia. This study assesses the difficulty in intubating patients with vertically unstable mandibular parasymphysis fracture with attached genial tubercles and associated musculature to the fractured segment.

METHODS

Randomized sampling was done from the cases with maxillofacial trauma planned for a surgical procedure under general anaesthesia. The inclusion criteria was to prospectively identify ten patients each of unilateral unfavourable mandibular parasymphysis fracture with genial tubercle attached to the displaced segment, with bilateral unfavourable mandibular parasymphysis fracture with genial tubercle attached to the displaced segment and with unilateral favourable mandibular parasymphysis fracture with genial tubercle attached to the un-displaced segment. All the patients were intubated by a single anaesthetist, who documented the difficulty in nasoendotracheal intubation using Intubation Difficulty Scale.

RESULTS

Nasoendotracheal intubation was found relatively easy in the study group with unilateral favourable mandibular parasymphysis fracture with genial tubercle attached to the un-displaced segment. Clinical difficulty in intubating the patients was maximum in the study group with bilateral unfavourable mandibular parasymphysis fracture with genial tubercle attached to the displaced segment.

CONCLUSION

Displacement of fractured mandible and resultant displacement of the genial musculature should be considered as a vital parameter for assessing difficulty during intubation.

Craniomaxillofacial trauma: synopsis of 14,654 cases with 35,129 injuries in 15 years

Craniomaxillofacial (CMF) trauma occurs in isolation or in combination with other serious injuries, including intracranial, spinal, and upper- and lower-body injuries. It is a major cause of expensive treatment and rehabilitation requirements, temporary or lifelong morbidity, and loss of human productivity. The aim of this study was to evaluate patterns of CMF trauma in a large patient sample within a 15-year time frame. Between 1991 and 2005, CMF trauma data were collected from 14,654 patients with 35,129 injuries at the Department of Cranio-Maxillofacial and Oral Surgery in Innsbruck, assessing a plethora of parameters such as injury type and mechanism as well as age and gender distribution over time. Three main groups of CMF trauma were evaluated: facial bone fractures, dentoalveolar trauma, and soft tissue injuries. Statistical comparisons were carried out using a chi-square test. This was followed by a logistic regression analysis to determine the impact of the five main causes for CMF injury. Older people were more prone to soft tissue lesions with a rising risk of 2.1% per year older, showing no significant difference between male and female patients. Younger patients were at higher risk of suffering from dentoalveolar trauma with an increase of 4.4% per year younger. This number was even higher (by 19.6%) for female patients. The risk of sustaining facial bone fractures increased each year by 4.6%. Male patients had a 66.4% times higher risk of suffering from this type of injury. In addition, 2550 patients (17.4%) suffered from 3834 concomitant injuries of other body parts. In summary, we observed changing patterns of CMF trauma over the last 15 years, paralleled by advances in refined treatment and management options for rehabilitation and reconstruction of patients suffering from CMF trauma.

An Unusual Case of Sudden Collapse in the Immediate Postoperative Period in a Young Healthy Female with Myxofibroma of the Maxilla

Benign myxofibromas of heart are well known to cause systemic inflammatory mediator release causing multiple complications ranging from fever and widespread effusions to DIC and shock. We report that in a particular case of maxillary myxofibroma, a shock-like state and widespread serous cavities effusion presented in the immediate postoperative period. The occurrence was possibly due to release of inflammatory mediators by the tumour, disseminated during tumour resection causing diffuse capillary leak, precipitated by fluid resuscitation, leading to decrease in plasma oncotic pressure.

Current perspectives in intra operative airway management in maxillofacial trauma

OBJECTIVE

Maxillofacial trauma presents a complex problem due to the disruption of normal anatomy. In such cases, we anticipate a difficult oral intubation that may hinder intraoperative IMF. Nasal and skull base fractures do not advocate use of nasotracheal intubation. Hence, other anesthetic techniques should be considered in management of maxillofacial trauma patients with occlusal derangement and nasal deformity. This study evaluates the indications and outcomes of anesthetic management by retromolar, nasal, submental intubation and tracheostomy.

METHODOLOGY

Of the 49 maxillofacial trauma cases reviewed, that required intraoperative IMF, 32 underwent nasal intubation, 9 patients had tracheostomy, 5 patients utilized submental approach and 3 underwent retromolar intubation.

RESULTS

Among patients who underwent nasal intubation, eight cases needed fiberoptic assistance. In retromolar approach, though no complication was encountered, constant monitoring was mandatory to avoid risk of tube displacement. Consequently, submental intubation required a surgical procedure which could result in a cosmetically acceptable scar. Though invasive, tracheostomy has its benefits for long term ventilation.

CONCLUSION

Intubation of any form performed in a maxillofacial trauma patient is complex and requires both sound judgement and considerable experience.

Traumatic airway management in Operation Iraqi Freedom

OBJECTIVES

To examine the role of head and neck surgeons in traumatic airway management in Operation Iraqi Freedom and to understand the lessons learned in traumatic airway management to include a simple airway triage classification that will guide surgical management.

STUDY DESIGN

Case series with chart review.

SETTING

Air Force Theater Hospital at Balad Air Base, Iraq.

SUBJECTS AND METHODS

The traumatic airway experience of 6 otolaryngologists/head and neck surgeons deployed over a 30-month period in Iraq was retrospectively reviewed.

RESULTS

One hundred and ninety-six patients presented with airway compromise necessitating either intubation or placement of a surgical airway over the 30-month timeframe. Penetrating face trauma (46%) and penetrating neck trauma (31%) were the most common mechanisms of injury necessitating airway control. The traumatic airways performed include 183 tracheotomies, 3 cricothyroidotomies, 9 complicated intubations, and 1 stoma placement. Red or emergent airways were performed in 10% of patients, yellow or delayed airways in 58% of patients, and green or elective airways in 32% of patients. Lastly, surgical repair of the laryngotracheal complex was performed in 25 patients with 16 thyroid cartilage repairs, 4 cricoid repairs, and 8 tracheal repairs.

CONCLUSIONS

The role of the deployed otolaryngologist in traumatic airway management was crucial. Potentially lifesaving airways (red/yellow airways) were placed in 68% of the patients. The authors' recommended treatment classification should optimize future traumatic airway management by stratifying traumatic airways into red (airway less than 5 minutes), yellow (airway less than 12 hours), or green categories (airway greater than 12 hours).