Blunt laryngeal fracture: another airbag injury

Systematic review of the anaesthetic management of non-iatrogenic acute adult airway trauma

INTRODUCTION

Non-iatrogenic trauma to the airway is rare and presents a significant challenge to the anaesthetist. Although guidelines for the management of the unanticipated difficult airway have been published, these do not make provision for the 'anticipated' difficult airway. This systematic review aims to inform best practice and suggest management options for different injury patterns.

METHODS

A literature search was conducted using Embase, Medline, and Google Scholar for papers after the year 2000 reporting on the acute airway management of adult patients who suffered airway trauma. Our protocol and search strategy are registered with and published by PROSPERO (http://www.crd.york.ac.uk/PROSPERO, ID: CRD42016032763).

RESULTS

A systematic literature search yielded 578 articles, of which a total of 148 full-text papers were reviewed. We present our results categorized by mechanism of injury: blunt, penetrating, blast, and burns.

CONCLUSIONS

The hallmark of airway management with trauma to the airway is the maintenance of spontaneous ventilation, intubation under direct vision to avoid the creation of a false passage, and the avoidance of both intermittent positive pressure ventilation and cricoid pressure (the latter for laryngotracheal trauma only) during a rapid sequence induction. Management depends on available resources and time to perform airway assessment, investigations, and intervention (patients will be classified into one of three categories: no time, some time, or adequate time). Human factors, particularly the development of a shared mental model amongst the trauma team, are vital to mitigate risk and improve patient safety.

Transglottic high frequency jet ventilation for management of laryngeal fracture associated with air bag deployment injury

Blunt laryngeal trauma is an uncommon injury associated with high prehospital mortality. Conventional airway management consists of awake tracheostomy. A case of laryngeal trauma associated with air bag deployment managed with tubeless suspension laryngoscopy with high frequency transglottic jet ventilation is presented. The advantages of this technique in the management of patients who are not good candidates for awake tracheostomy are discussed.

Upper airway injury and its management

Injuries to the upper airways are rare, but carry a significant morbidity and mortality. The degree of injury and presentation varies; thus recognition often requires a high index of suspicion based on mechanism. Effective management of laryngotracheal injuries begins with immediate control of the airway whether by orotracheal and surgical route. Definitive management of upper airway injuries relies on an understanding of the anatomy of the larynx, trachea and surrounding structures. Associated injuries are common and must be addressed concomitantly. Postoperative complications are frequent, requiring perioperative vigilance and long-term follow-up to ensure best outcome.

Management of laryngo-tracheal injuries associated with craniomaxillofacial trauma

PURPOSE

Laryngeal fractures can occur in association with maxillofacial injuries and may lead to life-threatening airway obstruction. Because of a low incidence and a paucity of peer-reviewed information, there is no universally accepted treatment protocol and few clinicians have extensive experience with complex laryngo-tracheal trauma. The purpose of this retrospective analysis is to validate a treatment protocol for the management of laryngo-tracheal injuries occurring in severely injured patients by assessing the outcome of a consecutive series of patients who were treated by the same surgeons over a 12-year period.

PATIENTS AND METHODS

All patients with laryngeal fractures admitted to the trauma service at Legacy Emanuel Hospital and Health Center (LEHHC; Portland, OR) from 1992 to 2004 were managed by the same surgeons, using a standard protocol based on the stability of the airway, and were retrospectively identified using the LEHHC Trauma Registry. Using information from the Trauma Registry and individual physician chart notes, a database was created for the purpose of assessing outcome. The following data were collected: age, gender, mechanism of injury, number of associated injuries and the Injury Severity Score, Glasgow Coma Scale on admission, initial hematocrit, airway management techniques, length of hospital stay, LEHHC laryngeal injury classification, treatment modality, disposition, and any available follow-up. Descriptive statistics were used to describe demographics, treatment, and outcome. Outcome measures were defined as complications, airway patency, speech, and deglutition.

RESULTS

A total of 16,465 patients were identified from the Trauma Registry as having sustained head, neck, or facial injuries, of which 37 patients were diagnosed with laryngeal fractures. Complete patient records were available for 27 patients (mean age, 35.5 +/- 15.3 years; range, 8 to 80 years; 23 males, 4 females) who were classified according to the LEHHC laryngeal injury classification scheme. Most patients sustained injuries as the result of blunt trauma (n = 23; 85.1%) and almost all of them had concomitant maxillofacial injuries (n = 26; 96.3%). Twenty patients (74.1%) required advanced airway intervention (tracheostomy, 14; endotracheal intubation, 5; emergent cricothyrotomy, 1), of which 13 patients underwent neck exploration. Eight of these patients required open reduction and internal fixation with titanium plates and screws, and 2 patients required the addition of an endolaryngeal stent. There was a general trend toward poorer outcome with increased LEHHC laryngeal injury classification. However, all patients were successfully decannulated, maintained patent airways, and ate a normal diet. Hoarseness was common in patients who underwent surgical exploration; however, long-term perioperative complications were rare and included infection requiring hardware removal (n = 1), unilateral vocal cord paralysis (n = 1), and subjective dysphagia.

CONCLUSION

Fractures of the larynx are uncommon injuries that are frequently associated with maxillofacial trauma and are potentially associated with significant morbidity. Management of laryngo-tracheal injuries using a protocol based on airway status as described in this report results in airway patency, functional vocal quality, and normal deglutition for almost all patients.

Laryngohyoid fractures after agonal falls: Not always a certain sign of strangulation

Haemorrhagic fractures of the thyroid cartilage and hyoid bone are frequently observed in cases of strangulation and often regarded as evidence for an assault against the neck. In contrast, two cases of laryngohyoid fractures after agonal falls in prone position are presented to draw attention to alternative causes of these injuries with special regard to practical medicolegal casework. A 45-year-old man collapsed at a fairground and died after unsuccessful resuscitation. He showed excoriations at his elbows and right knee, a crush injury at the mentum and his mandibular front teeth were knocked out. The upper parts of the chest and the head showed blue discolouration as a marked sign of congestion due to heart failure. The right coronary artery (RCA) was completely obturated by a 5 cm long post-stenotic thrombus with subsequent myocardial infarction of the lateral part of the left ventricle. Both superior horns of the thyroid cartilage were fractured with surrounding haemorrhage, the skin and muscles of the neck uninjured. In the second case, a 63-year-old woman with a mobility handicap had fallen from a 2m high lifting platform and was found in prone position with her wheelchair on her. Resuscitation efforts were not successful. Autopsy showed signs of blunt external force against head, neck, chest and limbs. Examination of the neck revealed haemorrhage of the right sternocleidomastoid muscle, both superior horns of the thyroid cartilage were fractured, as well as the hyoid bone, with slight haemorrhage of the surrounding soft tissue and mucosa. On the same level, the fifth intervertebral disk was ruptured, without any injury of the spinal cord. These cases demonstrate that laryngohyoid fractures should not be overestimated as unequivocal indication of neck compression and may well be caused by falls, even at ground level.

External laryngotracheal trauma

Differences in acute external injuries of the larynx and cervical trachea between peace-time and war trauma were studied. Twenty-six patients with peace-time injuries and 39 patients with war injuries were retrospectively analyzed. The incidence of peace-time laryngotracheal injuries was 0.91% of the total number of patients hospitalized for head and neck injuries. In the groups of wounded in action (WIA) and killed in action (KIA) with head and neck war injuries, the incidence of laryngotracheal injuries was 4.8 and 6.2%, respectively. According to the type of the wound, blunt injuries were most common among peace-time and penetrating wounds among war injuries. There was no difference between peace-time and war injuries according to the wound localization. War wounds were more severe, caused more extensive local tissue and organ defects, were associated with a greater number of lesions to the neck and other body regions and more often required reconstructive surgical procedures than peace-time injuries. The mortality of war laryngotracheal injuries was two times greater than that of peace-time lesions (9 vs. 3.8%).

Injuries caused by airbags: a review

With the number of vehicles on the road increasing, the safety aspects of motoring are becoming a progressively more important consideration in health care provision and policy. Airbags are a relatively new introduction into our vehicles. Unlike other mechanisms such as seat belts, they offer protection without the need for any action on the part of the occupant. However, the necessarily violent nature of their deployment has led to the emergence of patterns of injury as a direct result. Knowledge of the potential dangers posed by these systems is useful both for emergency department physicians in order to prevent important injuries being missed, and for car manufacturers using increas ingly modern technology to design more efficient mechanisms. We undertook a review of the current literature to ascertain the spectrum of injuries that have been attributed to the use of airbags, while putting this into the wider context of their protective contribution.

Laryngotracheal Injuries: Does Injury Mechanism Matter?

Laryngotracheal injuries are potentially lethal injuries whose diagnosis can be difficult. The purpose of this study was to delineate the effect of injury mechanism on the types of injury sustained and patient outcome. Patient records during a 7-year period were reviewed for injury mechanism, patient demographics, clinical presentation, patient evaluation, injury location, associated injuries, operative interventions, and outcome. Fifteen patients with laryngotracheal injuries were studied. Blunt injuries were more common (60%). Patient demographics, mortality, average length of stay, and Injury Severity Score were similar for both groups. Prevalent physical findings on examination included subcutaneous air (53%), hoarseness (47%), stridor (20%), and neck tenderness (27%). Diagnosis was confirmed by CT scan of the neck (66% blunt, 33% penetrating) or bronchoscopy (44% blunt, 66% penetrating). Injury location, patient disposition, and associated injures were the same for both groups. The most frequent operative intervention performed for both groups consisted of a primary airway repair via a collar incision within 8 hours of injury. Only patients with a laryngeal injury required concomitant tracheostomy regardless of mechanism. Blunt and penetrating neck injuries resulted in similar types of tracheal and laryngeal injuries. Anatomic location of the injury determined the need for tracheostomy. Regardless of mechanism, the overall outcome for patients with laryngotracheal injuries is good when injuries are recognized and treated expeditiously. A high level of suspicion must be maintained when evaluating all potential laryngotracheal injury patients irrespective of the mechanism of injury.

Air bag injuries--a literature review in consideration of demands in forensic autopsies

Air bags have been implicated in saving lives and reducing morbidity associated with motor vehicle crashes since their introduction in the mid-1970s. However, there is increasing evidence showing that air bags can be a source of injury and even death in certain circumstances. As the number of air bag-equipped vehicles increases, air bag-related injuries have occurred more frequently. Thus, a greater awareness of air bag-related injuries is required in forensic autopsies. Here, we review thoroughly the literature concerning air bag-related injuries with special regard to their nature and causative mechanisms, and summarize air bag-related injuries observed in adults, children and infants.