Original Research
Airway Management in Severe Combat Maxillofacial Trauma Matthew W. Keller, MD1, Peggy P. Han, MPH2, Michael R. Galarneau, MS2, and Matthew T. Brigger, MD, MPH1
Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.
Abstract Objectives. Airway stabilization is critical in combat maxillofacial injury as normal anatomical landmarks can be obscured. The study objective was to characterize the epidemiology of airway management in maxillofacial trauma. Study Design. Retrospective database analysis. Setting. Military treatment facilities in Iraq and Afghanistan and stateside tertiary care centers. Subjects. In total, 1345 military personnel with combat-related maxillofacial injuries sustained March 2004 to August 2010 were identified from the Expeditionary Medical Encounter Database using International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes. Methods. Descriptive statistics, including basic demographics, injury severity, associated injuries, and airway interventions, were collected. A logistic regression was performed to determine factors associated with the need for tracheostomy. Results. A total of 239 severe maxillofacial injuries were identified. The most common mechanism of injury was improvised explosive devices (66%), followed by gunshot wounds (8%), mortars (5%), and landmines (4%). Of the subjects, 51.4% required intubation on their initial presentation. Of tracheostomies, 30.4% were performed on initial presentation. Of those who underwent bronchoscopy, 65.2% had airway inhalation injury. There was a significant relationship between the presence of head and neck burn and association with airway inhalation injury (P \ .0001). There was also a significant relationship between the severity of facial injury and the need for intubation (P = .002), as well as the presence of maxillofacial fracture and the need for tracheostomy (P = .0001). Conclusions. There is a high incidence of airway injury in combat maxillofacial trauma, which may be underestimated. Airway management in this population requires a high degree of suspicion and low threshold for airway stabilization. Keywords tracheostomy, airway trauma, intubation, facial trauma, inhalation injury
Otolaryngology– Head and Neck Surgery 1–6 Ó American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0194599815576916 http://otojournal.org
Received October 23, 2014; revised February 5, 2015; accepted February 19, 2015.
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mergent airway stabilization is essential in patients with combat head and neck trauma, as a significant portion of potentially survivable wounds can be managed with appropriate airway techniques.1-3 Overall, the incidence of penetrating head and neck trauma is increasing in modern combat. The currently employed body armor effectively protects the chest and abdomen but leaves the face and neck exposed, resulting in a shift toward increased head and neck injuries.4-6 Penetrating neck trauma can cause immediate life-threatening airway issues, and severe maxillofacial injury can further exacerbate the difficulty of these emergent airway challenges. Military trauma is characterized by highvelocity penetrating and blunt injury, often delivered by large fragmentation creating massive tissue avulsion, a characteristic not experienced in motor vehicle accidents or other civilian settings. With blast-induced trauma, there is a high potential for associated upper airway injury. The mortality from blast injury can be caused by hemorrhage from nearby vascular structures or due to airway compromise.7 Specifically, the extensive neck trauma (vascular and airway) from high-velocity 1- to 3-mm improvised explosive device (IED) projectiles led Brennan et al3 to coin the phrase ‘‘small holes equals big pathology.’’ In addition, the association of inhalation injury with head and neck burn has been documented and is associated with increased injury mortality.8 Life-saving battlefield interventions such as intubation and
1 Department of Otolaryngology/Head and Neck Surgery, Naval Medical Center San Diego, San Diego, California, USA 2 Naval Health Research Center, San Diego, California, USA
This article was presented at the 2014 AAO-HNSF Annual Meeting & OTO EXPO; September 21-24, 2014; Orlando, Florida. The views expressed herein are our own and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, or the US government. Corresponding Author: Matthew Keller, MD, Department of Otolaryngology/Head and Neck Surgery, Naval Medical Center San Diego, 34800 Bob Wilson Drive, Bldg. 2, 2nd Deck, San Diego, CA 92134, USA. Email: [email protected]
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surgical airway control are pivotal in improving mortality from potentially survivable airway injuries. The objectives of this study were to document the types of airway management in service members presenting with combat maxillofacial trauma.
Methods Study Population The study was approved by the Naval Health Research Center Institutional Review Board (NHRC.2009.0023). A total of 5934 US military personnel with combat injuries were identified from the Expeditionary Medical Encounter Database (EMED) using a database query that ran from March 2004 to August 2010. The EMED, formerly known as the Navy-Marine Corps Combat Trauma Registry, is maintained by the Naval Health Research Center in San Diego, California.9 The EMED contains information abstracted from clinical records of US military personnel that are completed by providers at forward-deployed NavyMarine Corps treatment facilities in the combat zone and throughout the continuum of care.9 All records are reviewed by certified nurse coders and assigned codes from the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), Abbreviated Injury Scale (AIS) 2005, and Injury Severity Score (ISS) coding systems.10-13 (A complete list of ICD-9-CM and AIS diagnostic codes is available at www.otojournal.org.) Of the personnel identified, 1345 were treated for a maxillofacial injury, and of these, 239 had the presence of maxillofacial injury and an overall ISS 16, indicating the presence of significant combat trauma. The ISS is an overall score for patients with multiple traumatic injuries and is derived from the AIS,12,13 which is a scoring system that consists of 6 regions of the body: head and neck, face, chest, abdomen, extremity, and external. Each injury is assigned an AIS code based on the body region and injury specifics, and a severity score of 1 (minor) to 6 (unsurvivable) is assigned. To calculate the ISS, the AIS scores of the 3 most severely injured body regions are each squared and added together. The ISS has a maximum of 75, and a patient is automatically assigned an ISS of 75 if any regional AIS score is 6. The ISS has been demonstrated to correlate linearly with mortality, morbidity, and length of hospital stay.13 Injuries were classified into their primary mechanism of injury (ie, IED, gunshot wound [GSW], mortar, or landmine). The characteristics of the individuals that were recorded from the database included sex, age, rank, branch of service, type of injuries, and location injured (Afghanistan/Iraq). Specific variables associated with head and neck injuries included surface burns, inhalation injury, maxillofacial fractures, the need for intubation, and the timing of surgical airway interventions.
Statistical Analysis Frequency, percentile mean, and standard deviation (SD) were assessed as descriptive statistics of severe maxillofacial patients. Differences in demographic, military, and injury characteristics were examined with the Wilcoxon-Mann-
Table 1. Naval Health Research Center EMED Maxillofacial Injuries: Demographics and Clinical Indicators. Clinical Characteristic Total casualties Maxillofacial casualties Total No. of maxillofacial injuries Mean maxillofacial injuries/casualty Male sex Age, mean, y ISS 16 Military rank (enlisted) Intubated TBI
No.
%
5934 1345 2248 1.7 1284 23.4 239 207 123 153
100 22.7 — — 98.5 — 18.3 95.8 51.6 64
Abbreviations: EMED, Expeditionary Medical Encounters Database; ISS, Injury Severity Score; TBI, traumatic brain injury; —, not applicable.
Whitney t test for continuous data and with the x2 tests for categorical data. A comparison was made between the presence of maxillofacial fracture and the need for tracheostomy. Furthermore, we also explored the relationships between the overall severity of facial trauma (Facial AIS) as well as the presence of traumatic brain injury (TBI) and the need for tracheostomy. Additional comparison was made between the presence of head and neck burn and association with airway inhalation injury. The Cochran-Armitage Trend Test was performed to assess the trend association between the total body surface area (TBSA) burn percentage and inhalation injury. Univariate and multiple logistic regressions were conducted to evaluate the association between intubation and all covariates. Results were analyzed using a x2 test with a P value \.05 considered significant. Fisher’s exact test was used for any comparisons with a small variable sample size (n \ 10). Data management and statistical analyses were conducted with SAS Statistical Packages, version 9.3 (SAS Institute, Inc, Cary, North Carolina).
Results Complete patient demographics are listed in Table 1. When stratified according to the need for intubation, age, sex, military rank, mechanism of injury, TBI, and facial fracture injury did not differ between the groups. The most common mechanism of injury was IED (66%), followed by GSW (8%), mortar (5%), and landmines (4%). Most individuals were male (99.2%), and the mean age was 23 years. The service distribution of the severely injured service members was Marine Corps (69.8%), followed by Army (21.6%) and Navy (8.6%). Overall mean ISS (total body) was 26 (16 considered severe).14 As shown in Table 2, 51.4% (123/239) of the subjects required intubation on their initial presentation to level I/II triage facilities (field hospitals). Of all the intubations, 2 were done with field Combitubes, of which one was successfully placed. There was a significant relationship between the
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Table 2. Association of Intubation Status with Demographic Characteristics and Clinical Indicators of Severe Maxillofacial Trauma in Operation Iraqi Freedom/Operation Enduring Freedom, 2004-2010 (n = 239).a Characteristic Age, mean 6 SD, y Sex Male Female Service Marine Corps Army Navy Military rankb Enlisted Officer/warrant officer Mechanism of injury Blast GSW Other ISS, mean 6 SD AIS for face injury Severe (2) Moderate (1) TBI Yes No Tracheostomy Yes No Days to tracheostomyc Not performed 0-2 3-5 6-8 9 Inhalation injury Yes No Burn Yes No Facial fracture Yes No
Intubation (n = 123)
No Intubation (n = 116)
24.6 6 5.5
25 6 6.4
122 (51.5) 1 (50)
115 (48.5) 1 (50)
91 (56.5) 22 (35.5) 10 (62.5)
70 (43.5) 40 (64.5) 6 (37.5)
116 (51.3) 6 (50.0)
110 (48.7) 6 (50.0)
P Value .91 .96
.01
.93
.76 97 12 14 28
(50.5) (60.0) (51.8) 6 10
95 8 13 24.6
(49.5) (40.0) (48.2) 6 8.7
71 (61.2) 52 (42.3)
45 (38.8) 71 (57.7)
81 (53.0) 42 (48.8)
72 (47.0) 44 (51.2)
32 (69.6) 91 (47.2)
14 (30.4) 102 (52.8)
91 (47.2) 10 (52.6) 5 (71.4) 2 (50.0) 15 (93.8)
102 9 2 2 1
35 (76.1) 88 (45.6)
11 (23.9) 105 (54.4)
40 (67.8) 83 (46.1)
19 (32.2) 97 (53.9)
60 (55.0) 63 (48.5)
49 (45.0) 67 (51.5)
.003 .003
.54
.006
.002 (52.8) (47.4) (28.6) (50.0) (6.2) \.001
.004
.31
Abbreviations: AIS, Abbreviated Injury Scale; GSW, gunshot wound; ISS, Injury Severity Score; TBI, traumatic brain injury. a Values are presented as number (%) unless otherwise indicated. b Missing = 1. c Tracheostomy patients = 46. P = .04.
severity of facial injury and the need for intubation (AIS score 1, 42.3% intubated vs AIS score 2, 61.2% intubated; P = .00327, 2-sided). Intubations were performed more often
on patients with inhalation and head and neck burn injuries. Tracheostomies were also more likely to be performed on subjects who were intubated. With regard to surgical airway stabilization, 46 of 239 (19.3%) service members underwent tracheostomy. The distribution of the timing of the tracheostomy with regard to the number of days postinjury is shown in Table 2. Of the service members who underwent tracheostomies, 4 had an initial cricothyrotomy attempted in the field by a medic or corpsmen, of which 3 were successful. There was no correlation between the presence of TBI and need for tracheostomy. Among the service members, 46 of 239 (19.3%) underwent bronchoscopy, and of these, 30 were diagnosed with inhalation injury. All inhalation injuries were associated with a blast mechanism of injury. Furthermore, 58 of 239 (24.3%) of the service members sustained a burn to the head or neck region. The distribution of burn injury severity was first degree, 24.1% (14/58); second degree, 44.8% (26/ 58); and third degree, 31% (18/58). There was a significant relationship between the presence of head and neck burn and association with airway inhalation injury: burn (33/58 [56.9%] had inhalation injury) vs no burn (13/181 [7.2%] had inhalation injury) (P \ .0001, x2). When further subanalyzed, there was a significant effect of the severity of head and neck burn on the presence of airway inhalation injury (P = .02, Fisher’s exact test). The distribution of total body surface area (TBSA) burned was \20% = 29 of 58, 20% to 40% = 17 of 58, 40% to 60% = 8 of 58; and .60% = 4 of 58. There was an association between increasing TBSA and inhalation injury (trend test, P \ .0001). A subset of service members, 14 of 239 (5.9%), sustained injury to the cervical aerodigestive tract. The various types of injuries were thyroid/trachea (6), cricoid (3), vocal cords (3), supraglottis/arytenoids (1), and esophagus (1). Among the study population, 11.7% (28/239) underwent a neck exploration, and additional 2.5% (6/239) of the service members had a negative computed tomography angiogram (CTA) that precluded the need to perform neck exploration. In terms of maxillofacial injury, 45.6% (109/239) had at least 1 facial bone fracture. Table 3 shows the association of various maxillofacial injury characteristics with the need for tracheostomy. In univariate analysis, of those with maxillofacial fracture, 34% (37/109) underwent tracheostomy compared with 6.9% (9/130) who did not have a maxillofacial fracture (P \ .0001, 2-sided x2). When the severity of maxillofacial injury was compared with the need for tracheostomy, the results also reached significance (AIS 1, 8.1% had tracheostomy vs AIS 2, 31% had tracheostomy; P \ .0001, 2-sided). A comparison between mechanisms of injury (blast vs GSW) showed that GSW was associated with an increased need for tracheostomy (P = .03, 2-sided). Multiple logistic regression was conducted to assess the combined effects of the presence of tracheostomy and significant injury covariates. After adjusting for facial fracture, injury severity, and mechanism of injury, military personnel with facial fracture had higher odds of undergoing tracheostomy (odds ratio [OR], 4.1; 95% confidence interval
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Table 3. Percentage and ORs of Undergoing Tracheostomy for Severe Combat-Related Maxillofacial Trauma in Operation Iraqi Freedom/ Operation Enduring Freedom, 2004-2010. Tracheostomy Procedure, OR (95% CI) Variable Facial fracture No Yes Injury severity Moderate Severe Inhalation injury No Yes Burn No Yes Mechanism Blast GSW
Total (N = 239)
%
Unadjusted
Adjusteda
130 109
6.9 34.0
1.0 (6.9 (3.15-14.1)
1.0 (4.2 (1.3-13.2)
123 116
8.1 31
1.0 (5.1 (2.4-10.8)
1.0 (2.0 (0.6 - 6)
193 46
20.7 13.0
1.0 (0.6 (0.2-1.4)
—
180 59
21.7 11.9
1.0 (0.5 (0.2-1.2)
—
192 20
19.3 40
1.0 (2.8 (1.1-7.3)
1.0 (2.7 (0.9-8)
Abbreviations: CI, confidence interval; GSW, gunshot wound; OR, odds ratio; —, not applicable. a In multiple logistic regression, ORs were adjusted for facial fracture, injury severity, and mechanism of injury.
[CI], 1.3-13.2) compared with those without facial fracture (Table 3).
Discussion Historically, airway compromise is the third leading cause of potentially survivable combat deaths, behind hemorrhage and tension pneumothorax.1,2 Holcomb et al2 found that 8% of potentially survivable deaths among Special Operations Forces in Iraq and Afghanistan were caused by airway compromise. Kelly et al15 further demonstrated that airway compromise accounted for 15% of potentially survivable combat-related deaths in 2003-2004 and 10% in 2006. In their review of traumatic airway management in Operation Iraqi Freedom, Brennan et al3 reported that 68% of their patients with high-velocity penetrating face and neck trauma had potentially life-threatening airway injuries secured by the head and neck surgical team. This clearly demonstrates a need for timely and expert care in the management of the traumatic airway. In their aforementioned study, Brennan et al3 reviewed the operative records of deployed military head and neck surgeons in Iraq dealing with traumatic airways. On the basis of their experience over a 30-month period at a busy combat support hospital in Iraq, they established an algorithm for management of the traumatic airway. The algorithm is divided into urgency of airway management (red, 5 minutes; yellow, within 12 hours; green, .12 hours) and makes recommendations for intubation vs tracheotomy. Furthermore, on the basis of their surgical experience with high-velocity penetrating neck trauma (HVPNT), they advocated for the use of a selective neck exploration protocol. Symptomatic patients underwent immediate neck exploration following emergent airway control.
Asymptomatic HVPNT patients underwent a diagnostic workup with CTA and, if indicated, panendoscopy. If the diagnostic workup was negative, these HVPNT patients were observed. No HVPNT patients were managed by examination and observation only, which sometimes occurs in civilian lowvelocity penetrating neck trauma protocols.16,17 In Brennan’s experience,18 neck exploration for penetrating trauma was the third most common procedure performed by deployed head and neck surgeons, comprising 10.5% of their operative procedures. Among the neck explorations caused by HVPNT, 69% had intraoperative findings requiring surgical repair. It is interesting to note the frequency at which neck explorations were performed (11.7%) in our severe trauma population. Military surgeons deployed to austere settings can be confronted with mass casualty situations where they are forced to decide whether to rapidly stabilize and transport patients to a higher level of care or perform emergent neck exploration and delay progression through the trauma system. Notably, the most recent conflict provided the ability to perform advanced imaging (CTA) in forward-deployed combat support hospitals. Of service members in our study with penetrating neck trauma, 17.6% (6/34) avoided the need for neck exploration based on an asymptomatic clinical presentation and negative CTA. As we did not determine the effect of neck exploration on morbidity and mortality, no conclusions can be drawn regarding the success of the HVPNT protocol.19 In cases of disrupted airway anatomy, endotracheal intubation may not be the optimal choice for airway stabilization since it can lead to further destabilization.20-22 Likewise, in austere conditions where intubation would most likely occur without the presence of sedation or in the setting of massive
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airway hemorrhage, placement of a surgical airway could be more effective.20 Common indications for surgical airway intervention are oropharyngeal hemorrhage, glottic edema (as seen with anaphylaxis or inhalation injury), facial trauma, anatomic abnormalities, severe trismus, and inability to intubate/ ventilate.23 It is important to note that combat first responders may not have been able to reach the patient quickly due to enemy fire, and failed field cricothyrotomies do not imply that inadequate care was provided. Correct identification of anatomical landmarks is also more difficult in austere environments owing to limitations of sensory perception, poor lighting, lack of equipment, and environmental stressors.23 A recent review of airway management in 20 patients by medics at the point of injury showed that the most frequently used intervention was placement of an esophageal-tracheal airway.21 Three (15%) service members in their study underwent a surgical cricothyrotomy. In 2 separate analyses of battlefield cricothyrotomy in Iraq and Afghanistan from military trauma databases, the procedure was documented as successful in 67% and 68% of the cases, a similar figure to our study (75% success rate).22,23 Mabry et al1 documented a 0 of 5 rate of success with field cricothyrotomy during their review of autopsy records from casualties with documented potentially survivable airway injuries. A prospective, multicenter trial evaluating prehospital combat cricothyrotomy demonstrated an 82% procedural success rate and also noted that unsuccessful endotracheal intubation preceded 15% of cricothyrotomies.24 The correct establishment of a field airway is critical in improving success in potentially survivable combat head and neck injuries.1,22 The presence of inhalation injury was frequently noted (14.8%) and was exclusively associated with a blast mechanism of injury. Notably, only 19.2% of the individuals in the severe trauma subset had bronchoscopic examinations performed, and thus the incidence of airway inhalation injury may be much higher. Among the service members with head and neck burn injury, only 56.9% (33/58) underwent bronchoscopy. Whether this was due to a lack of equipment, training, or a reticence by the examining physician is unknown. Deployed providers should have the ability to perform flexible fiberoptic laryngoscopy to recognize early signs of inhalation injury and have a low threshold for referring patients for formal bronchoscopy, particularly in cases with head and neck burn injury. Standardized diagnostic and treatment guidelines for inhalation injury need to be established. Johnson et al8 recently reported on the therapeutic challenges commonly encountered when treating combat facial burns based on analysis of the US Army Institute of Surgical Research Burn database. Inhalation injury was frequently seen (61%), and of all the military burn injuries contained in the database, 67.1% involved the face. Earlier diagnosis of inhalation injury may lead to improved outcomes by initiating early treatment such as steroid medication and therapeutic debridement of soot and tracheal mucosal pseudomembranes that form commonly in inhalation injury.25,26 We attempted to determine if there was any mortality benefit of performing
bronchoscopic examinations in our study population, but due to a low overall mortality rate (2.1%), we were unable to draw any conclusions. Garner et al26 presented 2 novel technologies (tissue turgor measurement and spectrophotometric analysis of the intraoral mucosa) as potentially suitable battlefield airway assessment tools for forward deployed use as predictors of which burn injury patients will develop airway obstruction and which can be managed by observation alone. Similar to the findings in our study that GSW injuries led to more tracheostomies, the Brennan et al3 report on the management of patients with airway compromise also found that penetrating facial trauma was more commonly associated with a need for emergent airway control compared with blast injuries. Although they did not comment on the frequency of inhalation injuries, their most common indications for airway intervention were respiratory failure/ventilator dependence (12%), followed by closed head injury (7%), burns (1.5%), chest GSW (1.5%), and prior failed airway attempts (1%).3 In our study, facial fractures were associated with an increased frequency of tracheostomy but not an increased frequency of intubation. This may have been due to the fact that tracheostomies were performed instead of intubation in severe cases. Our study found that 30.4% of all tracheostomies were done at initial presentation on the day of injury without prior intubation, for reasons such as oropharyngeal bleeding, to facilitate completion of a complex pan-facial fracture repair or due to an inability to secure the airway by less invasive means. The remainder were performed after a variable period of observation, with the delayed procedures most likely associated with a prolonged anticipated need for or inability to wean from ventilatory support. The strengths of this study included the selection of high-acuity patients, the ability to confirm the information with radiologic and operative records, and the effective categorization of injury mechanisms by credentialed coders. Study weaknesses included lack of complete data on postinjury complications, such as pneumonia and sepsis, and incomplete information on the use of head and neck protective body armor, which precluded our ability to determine its effectiveness in injury prevention.
Conclusion Surgeons should be aware of the high potential for associated upper airway injury in combat maxillofacial trauma. The incidence of inhalation injury may be underestimated in cases of head and neck burn injury following blast trauma, and accordingly, the threshold for performing bronchoscopy should be lower in these situations. Gunshot wounds were associated with an increased need for tracheostomy compared with blast injury. Training should attempt to maximize exposure to the operative management of laryngotracheal trauma for surgeons and improve proficiency in cricothyrotomy for first-responder medics. In the words of Mabry et al,1 to improve survival from airway compromise on the battlefield, we need to ‘‘ensure that the right person, with the right equipment and training, is present at the right time.’’
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Acknowledgments The primary investigator, Dr Matthew Keller, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. We are military service members. This work was prepared as part of our official duties. Title 17, USC, §105 provides that ‘‘copyright protection under this title is not available for any work of the United States Government.’’ Title 17, USC, §101 defines a US government work as a work prepared by a military service member or employee of the US government as part of that person’s official duties.
Author Contributions Matthew W. Keller, study design, acquisition, analysis, interpretation, drafting, revising; Peggy P. Han, acquisition, analysis, interpretation, drafting, revising; Michael R. Galarneau, study design, interpretation, revising; Matthew T. Brigger, study design, analysis, interpretation, revising.
Disclosures Competing interests: None. Sponsorships: US Navy Bureau of Medicine and Surgery. Funding source: Wounded, Ill, and Injured/Psychological Health/ Traumatic Brain Injury Program under work unit no. 60808.
Supplemental Material Additional supporting information may be found at http://otojournal .org/supplemental.
References 1. Mabry RL, Edens JW, Pearse L, Kelly JF, Harke H. Fatal airway injuries during Operation Enduring Freedom and Operation Iraqi Freedom. Prehosp Emerg Care. 2010;14:272277. 2. Holcomb JB, McMullin NR, Pearse L, et al. Causes of death in U.S. Special Operations Forces in the global war on terrorism: 2001-2004. Ann Surg. 2007;245:986-991. 3. Brennan J, Gibbons MD, Lopez M, et al. Traumatic airway management in Operation Iraqi Freedom. Otolaryngol Head Neck Surg. 2011;144:376-380. 4. Rustemeyer J, Kranz V, Bremerich A. Injuries in combat from 1982-2005 with particular reference to those to the head and neck: a review. Br J Oral Maxillofac Surg. 2007;45:556-560. 5. Xydakis MS, Fravell MD, Nasser KE, Casler JD. Analysis of battlefield head and neck injuries in Iraq and Afghanistan. Otolaryngol Head Neck Surg. 2005;133:497-504. 6. Owens BD, Kragh JF Jr, Wenke JC, Macaitis J, Wade CE, Holcomb JB. Combat wounds in Operation Iraqi Freedom and Operation Enduring Freedom. J Trauma. 2008;64:295-299. 7. Clouse WD, Rasmussen TE, Peck MA, et al. In-theater management of vascular injury: 2 years of the Balad Vascular Registry. J Am Coll Surg. 2007;204:625-632. 8. Johnson BW, Madson AQ, Bong-Thakur, et al. Combat-related facial burns: analysis of strategic pitfalls. J Oral Maxillofac Surg. 2015;73:106-111.
9. Galarneau MR, Hancock WC, Konoske P, et al. The NavyMarine Corps Combat Trauma Registry. Mil Med. 2006;171: 691-697. 10. Wodzon TGE. The Abbreviated Injury Scale—2005. Des Plaines, IL: Association for the Advancement of Automotive Medicine; 2005. 11. American Medical Association. American Medical Association Hospital International Classification of Diseases, 9th Revision, Clinical Modification 2005. Chicago, IL: American Medical Association; 2005. 12. Baker SP, O’Neill B. The injury severity score: an update. J Trauma. 1976;16:882-885. 13. Baker SP, O’Neill B, Haddon W Jr, Long WB. The Injury Severity Score: a method for describing patients with multiple injuries and evaluating emergency care. J Trauma. 1974;14:187-196. 14. Copes WS, Champion HR, Sacco WJ, Lawnick MM, Keast SL, Bain LW. The Injury Severity Score revisited. J Trauma. 1988;28:69-77. 15. Kelly JF, Ritenour AE, McLaughlin DF, et al. Injury severity and causes of death from Operation Iraqi Freedom and Operation Enduring Freedom: 2003-2004 versus 2006. J Trauma. 2008;64:S21-S26. 16. Biffl WL, Moore EE, Rehse DH, Offner PJ, Franciose RJ, Burch JM. Selective management of penetrating neck trauma based on cervical level of injury. Am J Surg. 1997;174:678-682. 17. Brennan JA, Meyers AD, Jafek BW. Penetrating neck trauma: a 5-year review of the literature, 1983 to 1988. Am J Otolaryngol. 1990;11:191-197. 18. Brennan J. Experience of first deployed otolaryngology team in Operation Iraqi Freedom: the changing face of combat injuries. Otolaryngol Head Neck Surg. 2006;134:100-105. 19. Brennan J, Lopez M, Gibbons MD, et al. Penetrating neck trauma in Operation Iraqi Freedom. Otolaryngol Head Neck Surg. 2011;144:180-185. 20. Lockey D, Davies G, Coats T. Survival of trauma patients who have prehospital tracheal intubation without anaesthesia or muscle relaxants: observational study. BMJ. 2001;323:141. 21. Mabry RL, Frankfurt A. Advanced airway management in combat casualties by medics at the point of injury: a sub-group analysis of the reach study. J Spec Oper Med. 2011;11:16-19. 22. Mabry RL. An analysis of battlefield cricothyrotomy in Iraq and Afghanistan. J Spec Oper Med. 2012;12:17-23. 23. Hessert MJ, Bennett BL. Optimizing emergent surgical cricothyrotomy for use in austere environments. Wilderness Environ Med. 2013;24:53-66. 24. Barnard E, Ervin A, Mabry R, Bebarta V. Prehospital and en route cricothyrotomy performed in the combat setting: a prospective, multicenter, observational study. J Spec Oper Med. 2014;14:35-39. 25. Bai C, Huang H, Yao X, et al. Application of flexible bronchoscopy in inhalation lung injury. Diagn Pathol. 2013;8:174 26. Garner J, Jenner J, Parkhouse D. Prediction of upper airway closure in inhalational injury. Mil Med. 2005;170:677.
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Airway Management in Severe Combat Maxillofacial Trauma Matthew W. Keller, MD1, Peggy P. Han, MPH2, Michael R. Galarneau, MS2, and Matthew T. Brigger, MD, MPH1
Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.
Abstract Objectives. Airway stabilization is critical in combat maxillofacial injury as normal anatomical landmarks can be obscured. The study objective was to characterize the epidemiology of airway management in maxillofacial trauma. Study Design. Retrospective database analysis. Setting. Military treatment facilities in Iraq and Afghanistan and stateside tertiary care centers. Subjects. In total, 1345 military personnel with combat-related maxillofacial injuries sustained March 2004 to August 2010 were identified from the Expeditionary Medical Encounter Database using International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes. Methods. Descriptive statistics, including basic demographics, injury severity, associated injuries, and airway interventions, were collected. A logistic regression was performed to determine factors associated with the need for tracheostomy. Results. A total of 239 severe maxillofacial injuries were identified. The most common mechanism of injury was improvised explosive devices (66%), followed by gunshot wounds (8%), mortars (5%), and landmines (4%). Of the subjects, 51.4% required intubation on their initial presentation. Of tracheostomies, 30.4% were performed on initial presentation. Of those who underwent bronchoscopy, 65.2% had airway inhalation injury. There was a significant relationship between the presence of head and neck burn and association with airway inhalation injury (P \ .0001). There was also a significant relationship between the severity of facial injury and the need for intubation (P = .002), as well as the presence of maxillofacial fracture and the need for tracheostomy (P = .0001). Conclusions. There is a high incidence of airway injury in combat maxillofacial trauma, which may be underestimated. Airway management in this population requires a high degree of suspicion and low threshold for airway stabilization. Keywords tracheostomy, airway trauma, intubation, facial trauma, inhalation injury
Otolaryngology– Head and Neck Surgery 1–6 Ó American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015 Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/0194599815576916 http://otojournal.org
Received October 23, 2014; revised February 5, 2015; accepted February 19, 2015.
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mergent airway stabilization is essential in patients with combat head and neck trauma, as a significant portion of potentially survivable wounds can be managed with appropriate airway techniques.1-3 Overall, the incidence of penetrating head and neck trauma is increasing in modern combat. The currently employed body armor effectively protects the chest and abdomen but leaves the face and neck exposed, resulting in a shift toward increased head and neck injuries.4-6 Penetrating neck trauma can cause immediate life-threatening airway issues, and severe maxillofacial injury can further exacerbate the difficulty of these emergent airway challenges. Military trauma is characterized by highvelocity penetrating and blunt injury, often delivered by large fragmentation creating massive tissue avulsion, a characteristic not experienced in motor vehicle accidents or other civilian settings. With blast-induced trauma, there is a high potential for associated upper airway injury. The mortality from blast injury can be caused by hemorrhage from nearby vascular structures or due to airway compromise.7 Specifically, the extensive neck trauma (vascular and airway) from high-velocity 1- to 3-mm improvised explosive device (IED) projectiles led Brennan et al3 to coin the phrase ‘‘small holes equals big pathology.’’ In addition, the association of inhalation injury with head and neck burn has been documented and is associated with increased injury mortality.8 Life-saving battlefield interventions such as intubation and
1 Department of Otolaryngology/Head and Neck Surgery, Naval Medical Center San Diego, San Diego, California, USA 2 Naval Health Research Center, San Diego, California, USA
This article was presented at the 2014 AAO-HNSF Annual Meeting & OTO EXPO; September 21-24, 2014; Orlando, Florida. The views expressed herein are our own and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, or the US government. Corresponding Author: Matthew Keller, MD, Department of Otolaryngology/Head and Neck Surgery, Naval Medical Center San Diego, 34800 Bob Wilson Drive, Bldg. 2, 2nd Deck, San Diego, CA 92134, USA. Email: [email protected]
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surgical airway control are pivotal in improving mortality from potentially survivable airway injuries. The objectives of this study were to document the types of airway management in service members presenting with combat maxillofacial trauma.
Methods Study Population The study was approved by the Naval Health Research Center Institutional Review Board (NHRC.2009.0023). A total of 5934 US military personnel with combat injuries were identified from the Expeditionary Medical Encounter Database (EMED) using a database query that ran from March 2004 to August 2010. The EMED, formerly known as the Navy-Marine Corps Combat Trauma Registry, is maintained by the Naval Health Research Center in San Diego, California.9 The EMED contains information abstracted from clinical records of US military personnel that are completed by providers at forward-deployed NavyMarine Corps treatment facilities in the combat zone and throughout the continuum of care.9 All records are reviewed by certified nurse coders and assigned codes from the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), Abbreviated Injury Scale (AIS) 2005, and Injury Severity Score (ISS) coding systems.10-13 (A complete list of ICD-9-CM and AIS diagnostic codes is available at www.otojournal.org.) Of the personnel identified, 1345 were treated for a maxillofacial injury, and of these, 239 had the presence of maxillofacial injury and an overall ISS 16, indicating the presence of significant combat trauma. The ISS is an overall score for patients with multiple traumatic injuries and is derived from the AIS,12,13 which is a scoring system that consists of 6 regions of the body: head and neck, face, chest, abdomen, extremity, and external. Each injury is assigned an AIS code based on the body region and injury specifics, and a severity score of 1 (minor) to 6 (unsurvivable) is assigned. To calculate the ISS, the AIS scores of the 3 most severely injured body regions are each squared and added together. The ISS has a maximum of 75, and a patient is automatically assigned an ISS of 75 if any regional AIS score is 6. The ISS has been demonstrated to correlate linearly with mortality, morbidity, and length of hospital stay.13 Injuries were classified into their primary mechanism of injury (ie, IED, gunshot wound [GSW], mortar, or landmine). The characteristics of the individuals that were recorded from the database included sex, age, rank, branch of service, type of injuries, and location injured (Afghanistan/Iraq). Specific variables associated with head and neck injuries included surface burns, inhalation injury, maxillofacial fractures, the need for intubation, and the timing of surgical airway interventions.
Statistical Analysis Frequency, percentile mean, and standard deviation (SD) were assessed as descriptive statistics of severe maxillofacial patients. Differences in demographic, military, and injury characteristics were examined with the Wilcoxon-Mann-
Table 1. Naval Health Research Center EMED Maxillofacial Injuries: Demographics and Clinical Indicators. Clinical Characteristic Total casualties Maxillofacial casualties Total No. of maxillofacial injuries Mean maxillofacial injuries/casualty Male sex Age, mean, y ISS 16 Military rank (enlisted) Intubated TBI
No.
%
5934 1345 2248 1.7 1284 23.4 239 207 123 153
100 22.7 — — 98.5 — 18.3 95.8 51.6 64
Abbreviations: EMED, Expeditionary Medical Encounters Database; ISS, Injury Severity Score; TBI, traumatic brain injury; —, not applicable.
Whitney t test for continuous data and with the x2 tests for categorical data. A comparison was made between the presence of maxillofacial fracture and the need for tracheostomy. Furthermore, we also explored the relationships between the overall severity of facial trauma (Facial AIS) as well as the presence of traumatic brain injury (TBI) and the need for tracheostomy. Additional comparison was made between the presence of head and neck burn and association with airway inhalation injury. The Cochran-Armitage Trend Test was performed to assess the trend association between the total body surface area (TBSA) burn percentage and inhalation injury. Univariate and multiple logistic regressions were conducted to evaluate the association between intubation and all covariates. Results were analyzed using a x2 test with a P value \.05 considered significant. Fisher’s exact test was used for any comparisons with a small variable sample size (n \ 10). Data management and statistical analyses were conducted with SAS Statistical Packages, version 9.3 (SAS Institute, Inc, Cary, North Carolina).
Results Complete patient demographics are listed in Table 1. When stratified according to the need for intubation, age, sex, military rank, mechanism of injury, TBI, and facial fracture injury did not differ between the groups. The most common mechanism of injury was IED (66%), followed by GSW (8%), mortar (5%), and landmines (4%). Most individuals were male (99.2%), and the mean age was 23 years. The service distribution of the severely injured service members was Marine Corps (69.8%), followed by Army (21.6%) and Navy (8.6%). Overall mean ISS (total body) was 26 (16 considered severe).14 As shown in Table 2, 51.4% (123/239) of the subjects required intubation on their initial presentation to level I/II triage facilities (field hospitals). Of all the intubations, 2 were done with field Combitubes, of which one was successfully placed. There was a significant relationship between the
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Table 2. Association of Intubation Status with Demographic Characteristics and Clinical Indicators of Severe Maxillofacial Trauma in Operation Iraqi Freedom/Operation Enduring Freedom, 2004-2010 (n = 239).a Characteristic Age, mean 6 SD, y Sex Male Female Service Marine Corps Army Navy Military rankb Enlisted Officer/warrant officer Mechanism of injury Blast GSW Other ISS, mean 6 SD AIS for face injury Severe (2) Moderate (1) TBI Yes No Tracheostomy Yes No Days to tracheostomyc Not performed 0-2 3-5 6-8 9 Inhalation injury Yes No Burn Yes No Facial fracture Yes No
Intubation (n = 123)
No Intubation (n = 116)
24.6 6 5.5
25 6 6.4
122 (51.5) 1 (50)
115 (48.5) 1 (50)
91 (56.5) 22 (35.5) 10 (62.5)
70 (43.5) 40 (64.5) 6 (37.5)
116 (51.3) 6 (50.0)
110 (48.7) 6 (50.0)
P Value .91 .96
.01
.93
.76 97 12 14 28
(50.5) (60.0) (51.8) 6 10
95 8 13 24.6
(49.5) (40.0) (48.2) 6 8.7
71 (61.2) 52 (42.3)
45 (38.8) 71 (57.7)
81 (53.0) 42 (48.8)
72 (47.0) 44 (51.2)
32 (69.6) 91 (47.2)
14 (30.4) 102 (52.8)
91 (47.2) 10 (52.6) 5 (71.4) 2 (50.0) 15 (93.8)
102 9 2 2 1
35 (76.1) 88 (45.6)
11 (23.9) 105 (54.4)
40 (67.8) 83 (46.1)
19 (32.2) 97 (53.9)
60 (55.0) 63 (48.5)
49 (45.0) 67 (51.5)
.003 .003
.54
.006
.002 (52.8) (47.4) (28.6) (50.0) (6.2) \.001
.004
.31
Abbreviations: AIS, Abbreviated Injury Scale; GSW, gunshot wound; ISS, Injury Severity Score; TBI, traumatic brain injury. a Values are presented as number (%) unless otherwise indicated. b Missing = 1. c Tracheostomy patients = 46. P = .04.
severity of facial injury and the need for intubation (AIS score 1, 42.3% intubated vs AIS score 2, 61.2% intubated; P = .00327, 2-sided). Intubations were performed more often
on patients with inhalation and head and neck burn injuries. Tracheostomies were also more likely to be performed on subjects who were intubated. With regard to surgical airway stabilization, 46 of 239 (19.3%) service members underwent tracheostomy. The distribution of the timing of the tracheostomy with regard to the number of days postinjury is shown in Table 2. Of the service members who underwent tracheostomies, 4 had an initial cricothyrotomy attempted in the field by a medic or corpsmen, of which 3 were successful. There was no correlation between the presence of TBI and need for tracheostomy. Among the service members, 46 of 239 (19.3%) underwent bronchoscopy, and of these, 30 were diagnosed with inhalation injury. All inhalation injuries were associated with a blast mechanism of injury. Furthermore, 58 of 239 (24.3%) of the service members sustained a burn to the head or neck region. The distribution of burn injury severity was first degree, 24.1% (14/58); second degree, 44.8% (26/ 58); and third degree, 31% (18/58). There was a significant relationship between the presence of head and neck burn and association with airway inhalation injury: burn (33/58 [56.9%] had inhalation injury) vs no burn (13/181 [7.2%] had inhalation injury) (P \ .0001, x2). When further subanalyzed, there was a significant effect of the severity of head and neck burn on the presence of airway inhalation injury (P = .02, Fisher’s exact test). The distribution of total body surface area (TBSA) burned was \20% = 29 of 58, 20% to 40% = 17 of 58, 40% to 60% = 8 of 58; and .60% = 4 of 58. There was an association between increasing TBSA and inhalation injury (trend test, P \ .0001). A subset of service members, 14 of 239 (5.9%), sustained injury to the cervical aerodigestive tract. The various types of injuries were thyroid/trachea (6), cricoid (3), vocal cords (3), supraglottis/arytenoids (1), and esophagus (1). Among the study population, 11.7% (28/239) underwent a neck exploration, and additional 2.5% (6/239) of the service members had a negative computed tomography angiogram (CTA) that precluded the need to perform neck exploration. In terms of maxillofacial injury, 45.6% (109/239) had at least 1 facial bone fracture. Table 3 shows the association of various maxillofacial injury characteristics with the need for tracheostomy. In univariate analysis, of those with maxillofacial fracture, 34% (37/109) underwent tracheostomy compared with 6.9% (9/130) who did not have a maxillofacial fracture (P \ .0001, 2-sided x2). When the severity of maxillofacial injury was compared with the need for tracheostomy, the results also reached significance (AIS 1, 8.1% had tracheostomy vs AIS 2, 31% had tracheostomy; P \ .0001, 2-sided). A comparison between mechanisms of injury (blast vs GSW) showed that GSW was associated with an increased need for tracheostomy (P = .03, 2-sided). Multiple logistic regression was conducted to assess the combined effects of the presence of tracheostomy and significant injury covariates. After adjusting for facial fracture, injury severity, and mechanism of injury, military personnel with facial fracture had higher odds of undergoing tracheostomy (odds ratio [OR], 4.1; 95% confidence interval
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Table 3. Percentage and ORs of Undergoing Tracheostomy for Severe Combat-Related Maxillofacial Trauma in Operation Iraqi Freedom/ Operation Enduring Freedom, 2004-2010. Tracheostomy Procedure, OR (95% CI) Variable Facial fracture No Yes Injury severity Moderate Severe Inhalation injury No Yes Burn No Yes Mechanism Blast GSW
Total (N = 239)
%
Unadjusted
Adjusteda
130 109
6.9 34.0
1.0 (6.9 (3.15-14.1)
1.0 (4.2 (1.3-13.2)
123 116
8.1 31
1.0 (5.1 (2.4-10.8)
1.0 (2.0 (0.6 - 6)
193 46
20.7 13.0
1.0 (0.6 (0.2-1.4)
—
180 59
21.7 11.9
1.0 (0.5 (0.2-1.2)
—
192 20
19.3 40
1.0 (2.8 (1.1-7.3)
1.0 (2.7 (0.9-8)
Abbreviations: CI, confidence interval; GSW, gunshot wound; OR, odds ratio; —, not applicable. a In multiple logistic regression, ORs were adjusted for facial fracture, injury severity, and mechanism of injury.
[CI], 1.3-13.2) compared with those without facial fracture (Table 3).
Discussion Historically, airway compromise is the third leading cause of potentially survivable combat deaths, behind hemorrhage and tension pneumothorax.1,2 Holcomb et al2 found that 8% of potentially survivable deaths among Special Operations Forces in Iraq and Afghanistan were caused by airway compromise. Kelly et al15 further demonstrated that airway compromise accounted for 15% of potentially survivable combat-related deaths in 2003-2004 and 10% in 2006. In their review of traumatic airway management in Operation Iraqi Freedom, Brennan et al3 reported that 68% of their patients with high-velocity penetrating face and neck trauma had potentially life-threatening airway injuries secured by the head and neck surgical team. This clearly demonstrates a need for timely and expert care in the management of the traumatic airway. In their aforementioned study, Brennan et al3 reviewed the operative records of deployed military head and neck surgeons in Iraq dealing with traumatic airways. On the basis of their experience over a 30-month period at a busy combat support hospital in Iraq, they established an algorithm for management of the traumatic airway. The algorithm is divided into urgency of airway management (red, 5 minutes; yellow, within 12 hours; green, .12 hours) and makes recommendations for intubation vs tracheotomy. Furthermore, on the basis of their surgical experience with high-velocity penetrating neck trauma (HVPNT), they advocated for the use of a selective neck exploration protocol. Symptomatic patients underwent immediate neck exploration following emergent airway control.
Asymptomatic HVPNT patients underwent a diagnostic workup with CTA and, if indicated, panendoscopy. If the diagnostic workup was negative, these HVPNT patients were observed. No HVPNT patients were managed by examination and observation only, which sometimes occurs in civilian lowvelocity penetrating neck trauma protocols.16,17 In Brennan’s experience,18 neck exploration for penetrating trauma was the third most common procedure performed by deployed head and neck surgeons, comprising 10.5% of their operative procedures. Among the neck explorations caused by HVPNT, 69% had intraoperative findings requiring surgical repair. It is interesting to note the frequency at which neck explorations were performed (11.7%) in our severe trauma population. Military surgeons deployed to austere settings can be confronted with mass casualty situations where they are forced to decide whether to rapidly stabilize and transport patients to a higher level of care or perform emergent neck exploration and delay progression through the trauma system. Notably, the most recent conflict provided the ability to perform advanced imaging (CTA) in forward-deployed combat support hospitals. Of service members in our study with penetrating neck trauma, 17.6% (6/34) avoided the need for neck exploration based on an asymptomatic clinical presentation and negative CTA. As we did not determine the effect of neck exploration on morbidity and mortality, no conclusions can be drawn regarding the success of the HVPNT protocol.19 In cases of disrupted airway anatomy, endotracheal intubation may not be the optimal choice for airway stabilization since it can lead to further destabilization.20-22 Likewise, in austere conditions where intubation would most likely occur without the presence of sedation or in the setting of massive
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airway hemorrhage, placement of a surgical airway could be more effective.20 Common indications for surgical airway intervention are oropharyngeal hemorrhage, glottic edema (as seen with anaphylaxis or inhalation injury), facial trauma, anatomic abnormalities, severe trismus, and inability to intubate/ ventilate.23 It is important to note that combat first responders may not have been able to reach the patient quickly due to enemy fire, and failed field cricothyrotomies do not imply that inadequate care was provided. Correct identification of anatomical landmarks is also more difficult in austere environments owing to limitations of sensory perception, poor lighting, lack of equipment, and environmental stressors.23 A recent review of airway management in 20 patients by medics at the point of injury showed that the most frequently used intervention was placement of an esophageal-tracheal airway.21 Three (15%) service members in their study underwent a surgical cricothyrotomy. In 2 separate analyses of battlefield cricothyrotomy in Iraq and Afghanistan from military trauma databases, the procedure was documented as successful in 67% and 68% of the cases, a similar figure to our study (75% success rate).22,23 Mabry et al1 documented a 0 of 5 rate of success with field cricothyrotomy during their review of autopsy records from casualties with documented potentially survivable airway injuries. A prospective, multicenter trial evaluating prehospital combat cricothyrotomy demonstrated an 82% procedural success rate and also noted that unsuccessful endotracheal intubation preceded 15% of cricothyrotomies.24 The correct establishment of a field airway is critical in improving success in potentially survivable combat head and neck injuries.1,22 The presence of inhalation injury was frequently noted (14.8%) and was exclusively associated with a blast mechanism of injury. Notably, only 19.2% of the individuals in the severe trauma subset had bronchoscopic examinations performed, and thus the incidence of airway inhalation injury may be much higher. Among the service members with head and neck burn injury, only 56.9% (33/58) underwent bronchoscopy. Whether this was due to a lack of equipment, training, or a reticence by the examining physician is unknown. Deployed providers should have the ability to perform flexible fiberoptic laryngoscopy to recognize early signs of inhalation injury and have a low threshold for referring patients for formal bronchoscopy, particularly in cases with head and neck burn injury. Standardized diagnostic and treatment guidelines for inhalation injury need to be established. Johnson et al8 recently reported on the therapeutic challenges commonly encountered when treating combat facial burns based on analysis of the US Army Institute of Surgical Research Burn database. Inhalation injury was frequently seen (61%), and of all the military burn injuries contained in the database, 67.1% involved the face. Earlier diagnosis of inhalation injury may lead to improved outcomes by initiating early treatment such as steroid medication and therapeutic debridement of soot and tracheal mucosal pseudomembranes that form commonly in inhalation injury.25,26 We attempted to determine if there was any mortality benefit of performing
bronchoscopic examinations in our study population, but due to a low overall mortality rate (2.1%), we were unable to draw any conclusions. Garner et al26 presented 2 novel technologies (tissue turgor measurement and spectrophotometric analysis of the intraoral mucosa) as potentially suitable battlefield airway assessment tools for forward deployed use as predictors of which burn injury patients will develop airway obstruction and which can be managed by observation alone. Similar to the findings in our study that GSW injuries led to more tracheostomies, the Brennan et al3 report on the management of patients with airway compromise also found that penetrating facial trauma was more commonly associated with a need for emergent airway control compared with blast injuries. Although they did not comment on the frequency of inhalation injuries, their most common indications for airway intervention were respiratory failure/ventilator dependence (12%), followed by closed head injury (7%), burns (1.5%), chest GSW (1.5%), and prior failed airway attempts (1%).3 In our study, facial fractures were associated with an increased frequency of tracheostomy but not an increased frequency of intubation. This may have been due to the fact that tracheostomies were performed instead of intubation in severe cases. Our study found that 30.4% of all tracheostomies were done at initial presentation on the day of injury without prior intubation, for reasons such as oropharyngeal bleeding, to facilitate completion of a complex pan-facial fracture repair or due to an inability to secure the airway by less invasive means. The remainder were performed after a variable period of observation, with the delayed procedures most likely associated with a prolonged anticipated need for or inability to wean from ventilatory support. The strengths of this study included the selection of high-acuity patients, the ability to confirm the information with radiologic and operative records, and the effective categorization of injury mechanisms by credentialed coders. Study weaknesses included lack of complete data on postinjury complications, such as pneumonia and sepsis, and incomplete information on the use of head and neck protective body armor, which precluded our ability to determine its effectiveness in injury prevention.
Conclusion Surgeons should be aware of the high potential for associated upper airway injury in combat maxillofacial trauma. The incidence of inhalation injury may be underestimated in cases of head and neck burn injury following blast trauma, and accordingly, the threshold for performing bronchoscopy should be lower in these situations. Gunshot wounds were associated with an increased need for tracheostomy compared with blast injury. Training should attempt to maximize exposure to the operative management of laryngotracheal trauma for surgeons and improve proficiency in cricothyrotomy for first-responder medics. In the words of Mabry et al,1 to improve survival from airway compromise on the battlefield, we need to ‘‘ensure that the right person, with the right equipment and training, is present at the right time.’’
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Acknowledgments The primary investigator, Dr Matthew Keller, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. We are military service members. This work was prepared as part of our official duties. Title 17, USC, §105 provides that ‘‘copyright protection under this title is not available for any work of the United States Government.’’ Title 17, USC, §101 defines a US government work as a work prepared by a military service member or employee of the US government as part of that person’s official duties.
Author Contributions Matthew W. Keller, study design, acquisition, analysis, interpretation, drafting, revising; Peggy P. Han, acquisition, analysis, interpretation, drafting, revising; Michael R. Galarneau, study design, interpretation, revising; Matthew T. Brigger, study design, analysis, interpretation, revising.
Disclosures Competing interests: None. Sponsorships: US Navy Bureau of Medicine and Surgery. Funding source: Wounded, Ill, and Injured/Psychological Health/ Traumatic Brain Injury Program under work unit no. 60808.
Supplemental Material Additional supporting information may be found at http://otojournal .org/supplemental.
References 1. Mabry RL, Edens JW, Pearse L, Kelly JF, Harke H. Fatal airway injuries during Operation Enduring Freedom and Operation Iraqi Freedom. Prehosp Emerg Care. 2010;14:272277. 2. Holcomb JB, McMullin NR, Pearse L, et al. Causes of death in U.S. Special Operations Forces in the global war on terrorism: 2001-2004. Ann Surg. 2007;245:986-991. 3. Brennan J, Gibbons MD, Lopez M, et al. Traumatic airway management in Operation Iraqi Freedom. Otolaryngol Head Neck Surg. 2011;144:376-380. 4. Rustemeyer J, Kranz V, Bremerich A. Injuries in combat from 1982-2005 with particular reference to those to the head and neck: a review. Br J Oral Maxillofac Surg. 2007;45:556-560. 5. Xydakis MS, Fravell MD, Nasser KE, Casler JD. Analysis of battlefield head and neck injuries in Iraq and Afghanistan. Otolaryngol Head Neck Surg. 2005;133:497-504. 6. Owens BD, Kragh JF Jr, Wenke JC, Macaitis J, Wade CE, Holcomb JB. Combat wounds in Operation Iraqi Freedom and Operation Enduring Freedom. J Trauma. 2008;64:295-299. 7. Clouse WD, Rasmussen TE, Peck MA, et al. In-theater management of vascular injury: 2 years of the Balad Vascular Registry. J Am Coll Surg. 2007;204:625-632. 8. Johnson BW, Madson AQ, Bong-Thakur, et al. Combat-related facial burns: analysis of strategic pitfalls. J Oral Maxillofac Surg. 2015;73:106-111.
9. Galarneau MR, Hancock WC, Konoske P, et al. The NavyMarine Corps Combat Trauma Registry. Mil Med. 2006;171: 691-697. 10. Wodzon TGE. The Abbreviated Injury Scale—2005. Des Plaines, IL: Association for the Advancement of Automotive Medicine; 2005. 11. American Medical Association. American Medical Association Hospital International Classification of Diseases, 9th Revision, Clinical Modification 2005. Chicago, IL: American Medical Association; 2005. 12. Baker SP, O’Neill B. The injury severity score: an update. J Trauma. 1976;16:882-885. 13. Baker SP, O’Neill B, Haddon W Jr, Long WB. The Injury Severity Score: a method for describing patients with multiple injuries and evaluating emergency care. J Trauma. 1974;14:187-196. 14. Copes WS, Champion HR, Sacco WJ, Lawnick MM, Keast SL, Bain LW. The Injury Severity Score revisited. J Trauma. 1988;28:69-77. 15. Kelly JF, Ritenour AE, McLaughlin DF, et al. Injury severity and causes of death from Operation Iraqi Freedom and Operation Enduring Freedom: 2003-2004 versus 2006. J Trauma. 2008;64:S21-S26. 16. Biffl WL, Moore EE, Rehse DH, Offner PJ, Franciose RJ, Burch JM. Selective management of penetrating neck trauma based on cervical level of injury. Am J Surg. 1997;174:678-682. 17. Brennan JA, Meyers AD, Jafek BW. Penetrating neck trauma: a 5-year review of the literature, 1983 to 1988. Am J Otolaryngol. 1990;11:191-197. 18. Brennan J. Experience of first deployed otolaryngology team in Operation Iraqi Freedom: the changing face of combat injuries. Otolaryngol Head Neck Surg. 2006;134:100-105. 19. Brennan J, Lopez M, Gibbons MD, et al. Penetrating neck trauma in Operation Iraqi Freedom. Otolaryngol Head Neck Surg. 2011;144:180-185. 20. Lockey D, Davies G, Coats T. Survival of trauma patients who have prehospital tracheal intubation without anaesthesia or muscle relaxants: observational study. BMJ. 2001;323:141. 21. Mabry RL, Frankfurt A. Advanced airway management in combat casualties by medics at the point of injury: a sub-group analysis of the reach study. J Spec Oper Med. 2011;11:16-19. 22. Mabry RL. An analysis of battlefield cricothyrotomy in Iraq and Afghanistan. J Spec Oper Med. 2012;12:17-23. 23. Hessert MJ, Bennett BL. Optimizing emergent surgical cricothyrotomy for use in austere environments. Wilderness Environ Med. 2013;24:53-66. 24. Barnard E, Ervin A, Mabry R, Bebarta V. Prehospital and en route cricothyrotomy performed in the combat setting: a prospective, multicenter, observational study. J Spec Oper Med. 2014;14:35-39. 25. Bai C, Huang H, Yao X, et al. Application of flexible bronchoscopy in inhalation lung injury. Diagn Pathol. 2013;8:174 26. Garner J, Jenner J, Parkhouse D. Prediction of upper airway closure in inhalational injury. Mil Med. 2005;170:677.
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