34.4.1 What Airway Management Techniques Are Appropriate in PNI?
Airway management of the patient with penetrating neck trauma is intimidating and can be challenging even for the most skilled practitioners due to the coexistence of a potentially difficult airway and the need for rapid action.1,22,55 In addition, the rarity of PNI means that the experience of any one practitioner in the management of this injury can be limited.59 The need for airway control must be determined and the time available to achieve that control must be estimated. There must be a willingness to act quickly despite incomplete information as a delay in intervention can be hazardous,22 and there must be an ability to improvise and change plans under rapidly changing circumstances.27 Airway management decisions must be based on the patient's specific injuries, existing signs of airway compromise, the anticipated clinical course and risk of deterioration, the need for transport, and the patient's overall condition and level of cooperation, as well as planned diagnostic and therapeutic interventions.3,22 On examination, evidence of injury to an air-containing structure in the neck (SC emphysema, stridor, dysphagia, odynophagia, respiratory distress), vascular injury (hematoma, active bleeding, shock, palpable thrill, carotid bruit, absent or diminished pulses), and spinal cord injury (motor and sensory deficit) must be evaluated. The likelihood of difficult direct laryngoscopy must also be assessed. Emergency airway management may be necessary to secure a patent airway, in preparation for operative intervention, or as a part of airway evaluation in selective management of PNI.3 Emergency airway control is indicated in the presence of airway obstruction, respiratory failure, inability to protect the airway from aspiration, hemodynamic instability,3 and hard signs of vascular injury that mandate emergency surgical intervention.7,29 Edema, SC emphysema, or hematoma can produce sudden airway obstruction following a period of relative quiescence, and anatomic distortion can make intubation or a surgical airway more difficult to perform.22 The decision to observe a patient for impending airway compromise or to secure the airway to avoid a difficult intubation in the presence of anatomic distortion is a matter of clinical judgement.22,55 This decision must be based on the evidence on clinical examination of significant vascular, aerodigestive tract, and neurologic injury, and it must be recognized that if one choses to observe, airway obstruction may be sudden, complete, and irreversible. If there is evidence of injury to an air-containing structure in the neck (larynx, trachea, pharynx, esophagus), positive-pressure bag-mask-ventilation may be hazardous and can produce increased anatomic distortion and airway obstruction.2 Orotracheal intubation in the presence of laryngotracheal injury risks cannulation of a false passage, further disruption of damaged mucosa, and increased airway compromise.8,44,60 If there is evidence of significant vascular injury, airway management is indicated.22 A hematoma can expand in the deep tissue planes of the neck22 and airway compromise may proceed insidiously only to be followed by rapid and catastrophic deterioration.22
The timing, place, and method of airway control depend on the type of neck injury, the cardio-respiratory condition of the patient, the available resources, and the experience and skills of the resuscitation team.2,5
Several investigators have reported experience with airway management in PNI. Shearer et al reviewed the records of 107 patients who required an artificial airway from a series of 282 patients admitted with PNI.35 A surgical airway was the primary choice in 6%, RSI in 83%, awake bronchoscopic intubation in 7%, and blind nasal intubation in 4%. The success rates for these various techniques were: primary surgical, 100%; RSI, 98%; awake bronchoscopic, 100%; and blind nasal, 75%. Eight of the 107 patients had laryngotracheal injuries (8%) and 38 patients had vascular injuries (35.5%). RSI failed in two patients (2%) and a surgical airway was required. One blind nasal attempt failed (25%) and was followed by loss of the airway and death during attempted cricothyrotomy. Tracheotomy was performed as the primary airway in three of the eight patients with laryngotracheal injury. Of the nine patients who were hemodynamically unstable, five underwent a tracheotomy or cricothyrotomy in the ED. The authors concluded that airway control can be achieved in most patients with a penetrating neck injury by RSI or a surgical airway, and that a surgical airway should be strongly considered in patients who have wounds in proximity to the larynx who have stridor, dyspnea, hemoptysis, and SC emphysema.35
Mandavia et al conducted a retrospective study of ED intubations in patients presenting with PNI at a level I trauma unit over a 3-year period.61 During the study period, 748 patients with PNI were evaluated in the ED, of whom 82 (11%) required immediate airway management. Twenty-four of these 82 patients were excluded due to pre-hospital cardiac arrest or intubation. In the remaining 58 patients (45 GSWs, 12 SWs, 1 MVA), 39 underwent RSI with a 100% success rate. Thirty-three patients required one attempt, four patients required two attempts, and two required three attempts. Oxygen desaturation (<90%) occurred in two patients. Five unconscious patients were intubated orally without paralysis, and two underwent emergency tracheotomy. Flexible bronchoscopic intubation was attempted in 12 patients and was successful in 9. The three remaining patients were successfully intubated by RSI, although one patient required two attempts and experienced oxygen desaturation to 79%. Both patients who underwent emergency tracheotomy had GSWs and were unable to phonate properly. One of these patients had a laryngeal injury confirmed by endoscopic laryngoscopy prior to tracheotomy. Oral endotracheal intubation was the definitive technique in 47 of the 58 patients and was successful 100% of the time it was employed. The authors concluded that RSI was safe and effective in all of the cases in which it was attempted, and that practitioners with airway expertise should consider using RSI in the setting of PNI.61
Eggen and Jorden reviewed the charts of 114 patients with penetrating injury that breeched the platysma.30 The mechanism of injury was GSW in 59, SW in 39, shotgun wound (SGW) in 7, and miscellaneous in 9 patients. Sixty-nine patients required intubation, of whom 26 were intubated urgently. Urgent airway control was considered necessary in the presence of acute airway distress, airway compromise from blood or secretions, extensive SC emphysema, tracheal shift, or severe alteration of mental status. Eight of the 26 urgent intubations were initially unsuccessful, and six of these required an alternative technique. Four of these were failed oral intubation, three of whom were subsequently managed via the open wound, and one via a tracheotomy. Two of the six were failed nasotracheal intubations both of whom required emergency tracheotomy. Of the 26 patients who required urgent airway control, 9 required a tracheotomy and 5 of these patients had diffuse SC emphysema. Of the 98 patients with zone II injury, 22% required urgent airway control whereas all 3 patients with zone I injury and 5 of 13 (38%) with zone III injury required urgent airway control. The authors noted that a variety of approaches to airway management have been documented to be successful, and that no approach should be dismissed unless specific circumstances contraindicate it or make it technically impossible.30 It should be noted that these cases occurred and that this study was published at a time when RSI was not widely practiced by emergency physicians.
Bell et al performed a retrospective analysis of 134 patients with PNI, of whom sixty-five sustained wounds that violated the platysma.7 There were 31 patients with GSWs, 63 SWs, 13 flying glass injuries, and 15 who were impaled. Eight patients did not require airway management, except for the purpose of general anesthesia. Of the 59 patients who required emergency airway management, 48 were successfully intubated orally in the field. There were two failed intubations that required emergency tracheotomy on arrival, and seven additional tracheotomies were performed for airway compromise.7
Tallon et al performed a retrospective review of the airway management of PNI in a Canadian tertiary care center.62 Nineteen patients were identified over the 11-year period of the study. Three patients were not intubated. Of the remaining 16, 5 were intubated in the pre-hospital setting, 6 in the ED, and 5 in the OR. Eight patients were intubated awake and eight others underwent RSI. No adverse airway-related outcomes were identified in either group.62
Thoma et al performed a prospective observational study of 203 patients with PNI who presented to Groote Schuur Hospital in Cape Town between July 2004 and July 2005.6 Of these, 159 patients presented with stab wounds and 42 with low-velocity gunshot wounds. A vascular injury was identified in 27 patients, pharyngoesophageal injury in 18, and an upper airway injury in 8. Four patients had a laryngeal injury and four had tracheal injuries. Twenty-five patients required surgical intervention, and eight additional patients had endovascular procedures. Six patients underwent tracheotomy, four of whom had airway compromise associated with oropharyngeal injury. One of the patients with laryngeal injury required tracheotomy and one patient with a complete C4 spinal cord injury required long-term ventilation. Patients with airway compromise and hemodynamic stability were intubated either by oral endotracheal intubation or if that failed, emergency cricothyrotomy. However, there were no failed intubations requiring a surgical airway. The details of the technique of intubation were not provided.6
Grewal et al retrospectively analyzed the records of all patients admitted to a level I trauma center who required operative management for penetrating laryngotracheal injury over a 15-year period.25 Of the 57 patients with penetrating laryngotracheal injury, 32 had sustained GSWs and 25 had sustained SWs. Five patients were hemodynamically unstable on arrival. Emergency airway management was required in 32 of the 57 patients. Oral endotracheal intubation was performed in 14, cricothyrotomy in 3, and tracheotomy in 15. Eight of the emergency tracheotomies were performed in the ED. Forty-four patients underwent tracheotomy in the course of their resuscitation and management. The authors concluded that endotracheal intubation can be safely accomplished in selected patients with penetrating laryngotracheal injuries.25 They suggested that patients with minor to moderate laryngotracheal injury can be safely intubated whereas patients with major laryngeal injuries required individualized management. If the expertise required to perform tracheotomy in the emergency department is limited, then cricothyrotomy was felt to be the safest alternative.25
In a retrospective review of laryngotracheal trauma at two major hospitals between 1996 and 2004, Bhojani et al identified 52 patients who had sustained penetrating laryngotracheal injury.24 There were 26 GSWs and 24 SWs; 24 of the 52 patients required an emergency airway. Endotracheal intubation was performed in 20, tracheotomy in 3, and cricothyrotomy in 1. One patient, who was previously intubated, subsequently required emergency cricothyrotomy in the OR. Twelve of the patients who were intubated or who underwent cricothyrotomy required revision to tracheotomy. An additional seven patients required operative tracheotomy. The authors concluded that either routine intubation or a tracheotomy can be used to secure the airway.24
In a retrospective study of aerodigestive injuries of the neck, Vassiliu et al reviewed 1562 patients with neck trauma and identified 998 patients who had sustained penetrating injury.9 There were 432 GSWs and 524 SWs during the 5-year study period. Blunt trauma produced aerodigestive injury in 7 patients, GSWs in 44, and SWs in 25. Forty-two patients with other penetrating mechanisms did not sustain aerodigestive injury. Forty of the seventy-six patients with aerodigestive injury required an emergency airway in the ED, one of whom had sustained blunt trauma. Orotracheal intubation was successful in 28 patients. In nine patients orotracheal intubation failed, and a cricothyrotomy was performed. Flexible endoscopic intubation was performed in three patients. Of the 38 patients with laryngotracheal trauma, 20 required an emergency airway in the ED. Flexible endoscopic nasotracheal intubation was performed in one patient. Of the remaining patients, RSI failed in five and a cricothyrotomy was performed. The failure rate for RSI was 23% in the GSW group and 20% in the SW group. Twenty-five of 49 patients with isolated pharyngoesophageal injuries required an emergency airway, 16 due to airway compromise secondary to pharyngeal hematoma, and 9 due to shock. RSI was successful in 17 of these 25 patients. A flexible endoscopic intubation was performed in three patients and a cricothyrotomy in five. The authors concluded that RSI is the easiest technique in most cases of aerodigestive injury. However, in the presence of large hematomas, RSI can be difficult and potentially dangerous.9 If an RSI is undertaken, an experienced practitioner should be ready to perform a surgical airway, should the orotracheal intubation fail. In 22.5% of attempted RSI in this study, the airway was lost and a cricothyrotomy was necessary, highlighting the importance of the concept of a double set-up. The authors suggest that flexible endoscopic nasotracheal intubation is the safest approach provided that the patient has adequate cardiovascular stability.9
Bumpous et al performed a retrospective review of 16 patients with penetrating injury to the visceral compartment of the neck who were treated in a level I trauma center over an 8-year period.28 There were nine handgun injuries, one shotgun injury, five stab wounds, one razor slash, and two victims of penetrating trauma associated with a motor vehicle accident. Three patients sustained zone I injury, eleven zone II injury, and two patients, zone III injury. Eleven patients sustained tracheal injury, six esophageal injury, and five laryngeal injury. Multiple sites of aerodigestive tract injury occurred in 13 patients. Tracheotomy was required in 12 of the 16 patients.
Gussack et al reported a series of 117 patients with PNI of whom 8 had penetrating laryngotracheal injury.63 Of these eight patients with penetrating laryngotracheal injury, six underwent orotracheal intubation and two were intubated through the wound.63 Four of those who underwent orotracheal intubation subsequently required tracheotomy. Both patients intubated through the wound required tracheotomy. No untoward effect occurred related to the orotracheal intubation.63 The authors also reviewed an additional 392 cases of laryngotracheal trauma from 12 published series which included 123 cases of penetrating trauma. Seventy-three percent of the 392 cases required a tracheotomy. Gussack et al also reported a series of 12 patients with penetrating trauma to the laryngotracheal complex.59 The mechanism of injury was GSW in five patients and SW in seven. Nine of the patients with penetrating laryngotracheal injury required active airway control and were orally intubated. Three required an emergency tracheotomy, two with SWs and one patient with a GSW. No intubation failures were reported. The authors felt that intubation is the primary method of airway control, and is generally more expeditious than tracheotomy in the majority of patients. However, they went on to state that the operator should move quickly to tracheotomy if intubation is difficult.59 Cricothyrotomy was said to be relatively contraindicated if laryngeal trauma is suspected59 although it is not clear that this is an evidence based position.
There is no uniform agreement on the airway management method of choice in penetrating neck injury.3 Controversy persists and management varies from institution to institution.2 The method chosen must depend on the practitioner's expertise with the various approaches2 and, in general, the technique with which the practitioner is most comfortable is utilized.55 However, familiarly with multiple approaches to secure the airway is required as success with any single technique is not guaranteed,55 and back up plans must be in place should the primary technique fail.22 In most cases, an orotracheal intubation is the easiest and most appropriate technique.1,2 The use of rapid-sequence intubation in PNI was reported by Shearer et al with a success rate of 98%35 and by Mandavia et al with a success rate of 100%.61 Bell et al reported 2 failed and 48 successful oral intubations in PNI.7 However, Eggen and Jorden reported 8 out of 26 initially unsuccessful intubations in PNI, 4 of which were failed oral intubation.30 Gussack et al reported successful orotracheal intubation in penetrating laryngotracheal injury.59,63 However, Vassiliu et al reported a failure rate of 22.5% with RSI in penetrating aerodigestive injury.9 Rapid-sequence intubation can be difficult and potentially dangerous in the presence of PNI and should only be undertaken if judged likely to be successful and the personnel and equipment necessary to establish a surgical airway must be immediately available should the intubation fail (ie, a double set-up).
Awake flexible endoscopic intubation has been advocated as the safest method for most patients with PNI and should be considered in all cooperative patients with suspected airway injury.3 However, this technique may only be feasible in stable patients who are not in severe respiratory distress, and is usually not possible in combative patients or when immediate airway control is required.3,8 The nasal route may require less patient cooperation. The flexible endoscopic technique has the advantage that airway injuries may be identified and the endotracheal tube can be passed distal to the injury. The flexible bronchoscope can also be used to perform the intubation as part of a rapid-sequence intubation technique.8 This variation of technique may be useful in combative patients who otherwise do not have predictors of difficult intubation.8 In the moribund or apneic patient, or in the presence of massive upper airway bleeding, awake orotracheal intubation may be the most expeditious approach.8
If an airway must be immediately established and endotracheal intubation fails, then cricothyrotomy is indicated.9,22,44,60 Conversion to tracheotomy can be performed as soon as the clinical situation permits.44 Cricothyrotomy has also been considered to be contraindicated if the exact location of the airway injury is unknown3 and tracheotomy had been advocated in this setting.3 In the presence of laryngotracheal injury, if uncertainty exists about the difficulty or safety of intubation, an awake tracheotomy under local anesthesia can be performed under controlled conditions if the patient's condition permits.2,44,60 However, an awake tracheotomy requires patient cooperation and the difficulties associated with the performance of a surgical airway in the presence of anatomic distortion in a restless hypoxic patient cannot be overemphasized.8 In extreme circumstances in which a surgical airway is immediately required, most practitioners would consider a cricothyrotomy to be the procedure of choice.30,39 and emergency tracheotomy is not considered an appropriate method to establish an emergency definitive airway.27 Blind nasal intubation has been reported in the management of PNI with a success rate of 90%.64 However, most authors agree that blind intubation techniques should not be used in PNI because of the risk of producing further injury and complete airway obstruction.3
34.4.2 How Was the Patient's Airway Managed?
The patient developed increasing respiratory distress following arrival in the ED. A surgeon, an anesthesiologist, and an emergency physician were at the bedside. Options for airway management were discussed. No bronchoscope was immediately available. The degree of respiratory distress rapidly increased and awake tracheotomy was not considered to be feasible. A rapid-sequence intubation (RSI) was initiated. The necessary equipment was opened and the surgeon was ready to perform a surgical airway should intubation fail.
On direct laryngoscopy a Grade 3 (epiglottis only) view was obtained with a #4 MacIntosh blade. The Eschmann tracheal introducer (bougie) was successfully passed on the first attempt and an 8.0-mm ID endotracheal tube (ETT) easily passed into the trachea over the bougie. Edema of the pharynx and larynx was noted. Endotracheal tube position was confirmed by colorimetric carbon dioxide analysis.