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Definitive airway management after prehospital supraglottic rescue airway in pediatric trauma
Journal of Pediatric Surgery 53 (2018) 352–356
Contents lists available at ScienceDirect
Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Definitive airway management after prehospital supraglottic rescue airway in pediatric trauma☆ Matthew C. Hernandez b, Ryan M. Antiel a, Karthik Balakrishnan c, Martin D. Zielinski b, Denise B. Klinkner a,⁎ a b c
Department of Pediatric Surgery, Mayo Clinic, Rochester, MN Department of Trauma, Critical Care and General Surgery, Mayo Clinic, Rochester, MN Department of Otolaryngology, Mayo Clinic, Rochester, MN
a r t i c l e
i n f o
Article history: Received 3 October 2017 Accepted 4 October 2017 Key words: Supraglottic airway Trauma Pediatric Prehospital ATLS
a b s t r a c t Introduction: Supraglottic airway (SGA) use and outcomes in pediatric trauma are poorly understood. We compared outcomes between patients receiving prehospital SGA versus bag mask ventilation (BVM). Methods: We reviewed pediatric multisystem trauma patients (2005–2016), comparing SGA and BVM. Primary outcome was adequacy of oxygenation and ventilation. Additional measures included tracheostomy, mortality and abbreviated injury scores (AIS). Results: Ninety patients were included (SGA, n = 17 and BVM, n = 73). SGA patients displayed increased median head AIS (5 [4–5] vs 2 [0–4], p = 0.001) and facial AIS (1 [0–2] vs 0 [0–0], p = 0.03). SGA indications were multiple failed intubation attempts (n = 12) and multiple failed attempts with poor visualization (n = 5). Median intubation attempts were 2 [1–3] whereas BVM patients had none. Compared to BVM, SGA patients demonstrated inadequate oxygenation/ventilation (75% vs 41%), increased tracheostomy rates (31% vs 8.1%), and increased 24-h (38% vs 10.8%) and overall mortality (75% vs 14%) (all p b 0.05). Conclusions: Escalating intubation attempts and severe facial AIS were associated with tracheostomy. Inadequacy of oxygenation/ventilation was more frequent in SGA compared to BVM patients. SGA patients demonstrate poor clinical outcomes; however, SGAs may be necessary in increased craniofacial injury patterns. These factors may be incorporated into a management algorithm to improve definitive airway management after SGA. © 2017 Elsevier Inc. All rights reserved.
Inadequate airway management may lead to cardiovascular arrest and complicate subsequent life-saving interventions in the injured patient [1]. Several airway control devices and techniques are available to assist prehospital providers in order to maintain ventilation and oxygenation. These include bag valve mask (BVM) ventilation, direct laryngoscopy with endotracheal intubation (ETI) and adjunct supraglottic airway devices such as the laryngeal mask airway, Combitube, and King Airway Device (King LT-D; King Systems, Noblesville, IN) [2]. Despite the variety of options available to secure the airway, there is a paucity of data evaluating the outcomes of supraglottic rescue airway devices, especially in pediatric trauma. In the pediatric population, prehospital airway interventions may not be superior to BVM ventilation. Previous work has demonstrated moderate prehospital ETI failure rates with subsequent tube malposition [7–11]. These studies concluded that prehospital pediatric ☆ The authors have no financial conflicts for the generation of this work. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. ⁎ Corresponding author at: Mayo Clinic, 200 First Street SW, Rochester, MN 55905. E-mail addresses: [email protected] (M.C. Hernandez), [email protected] (R.M. Antiel), [email protected] (K. Balakrishnan), [email protected] (M.D. Zielinski), [email protected] (D.B. Klinkner). https://doi.org/10.1016/j.jpedsurg.2017.10.004 0022-3468/© 2017 Elsevier Inc. All rights reserved.
advanced airway interventions may not be necessary to achieve adequate ventilation/oxygenation while also recognizing that a proportion of patients may require advanced airway control maneuvers, including supraglottic rescue airway insertion. Supraglottic rescue airway devices may provide an alternative method to achieve airway control. Currently, no studies (1) describe supraglottic rescue airway utilization in pediatric trauma patients or (2) compare this adjunct to the standard of care (BVM). This makes it difficult to estimate how these devices might affect airway and trauma outcomes [12]. Supraglottic rescue airways provide more facile airway control for difficult airway patients. However, they are not without risk and may have size limitations in smaller pediatric patients [2,13–15]. Complications from insertion range from malposition to dislodgement [16–18]. Furthermore, the optimal method for safe transition to a definitive airway and the most appropriate definitive airway type have yet to be determined [19,20]. Therefore, the objective of this study is to compare outcomes, specifically adequacy of oxygenation and/or ventilation at time of admission among pediatric patients who received prehospital supraglottic airways versus BVM ventilation. We hypothesize that patients with increased craniofacial injury patterns and difficult airways in the prehospital setting would be more likely to require advanced airway techniques, including surgical tracheostomy, as a definitive airway.
M.C. Hernandez et al. / Journal of Pediatric Surgery 53 (2018) 352–356
1. Methods 1.1. Patient identification This study was approved by the Mayo Clinic Institutional Review Board. We performed a single center retrospective study that examined patients who were ≤18 years old and incurred multisystem trauma during 2005–2016. Multisystem trauma was defined as an Injury Severity Score of ≥9. Patients were identified from the Mayo Clinic Trauma Center database for (1) insertion of a supraglottic rescue airway (King Airway Device, King LT-D, Noblesville, IN) or (2) prehospital bag valve mask ventilation (BVM) with subsequent endotracheal intubation (ETI) in the resuscitation bay after airway evaluation. Patients who received endotracheal intubation in the prehospital setting, received a supraglottic rescue airway device other than a King LT-D, refused consent to research, and who did not display multisystem trauma (ISS b9) were excluded. 1.2. Institutional prehospital airway care Patients were transported by rotor wing or via ground transportation. Patients that were transported by rotor wing received care from critical care trained flight nurses. Patients that were transported via ground transportation received care from paramedics. At our institution, injured patients that require advanced prehospital airway management meet criteria for our highest level trauma team activation. Emergency Medicine, Surgery, and Anesthesia physicians are present in the trauma resuscitation bay at patient arrival. For patients ≤ 14 years of age, the pediatric surgeon responds within 15 min, and the pediatric critical care physician also responds. Each prehospital airway intervention is reviewed in detail by the directors of Medical Transportation, Emergency Medicine, Trauma Surgery, and Anesthesia. A prehospital advanced airway control algorithm has been defined and implemented by this group for standardized practice and safe patient care. See Fig. 1. 1.3. Primary outcome and secondary predictors Primary outcome was adequacy of oxygenation and ventilation at the time of hospital arrival. Inadequate oxygenation saturation was defined as (b 92%) using pulse oximetry or a partial pressure of carbon dioxide (PCO2) of (N 45 mmHg) using arterial blood gas. Secondary outcomes included need for tracheostomy, mortality and abbreviated injury scores (AIS). Patient demographics, transportation method and duration, traumatic mechanism, trauma severity (ISS and abbreviated injury scores (AIS)), admission vital signs (heart rate, respiratory rate, systolic and diastolic blood pressure and oxygen saturation), Glasgow Coma Score (GCS), 24 h and overall mortality, frequency and type of prehospital airway complications, and number of prehospital airway attempts, durations of intensive care, mechanical ventilation and overall hospital stay were abstracted from the electronic record. 1.4. Statistical analyses Summary statistical and univariate analyses were performed. Continuous variables were described using means with standard deviations (SD) if normally distributed and medians with interquartile ranges [IQR] for non-normally distributed data. Two-tailed t-tests were performed between prehospital airway groups (supraglottic rescue airway versus BVM with subsequent inpatient ETI). In order to assess which factors were associated with an increased need for surgical definitive airway (open tracheostomy), logistic nominal regression was applied to statistically significant and clinically important variables. Categorical variables were summarized as proportions, and differences were evaluated using chi-square analysis. Statistical inferences were based on 2tailed tests with significance set at P b 0.05. All patients meeting
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inclusion criteria were included in the analysis; a priori power analysis was not performed owing to lack of data to suggest an appropriate effect size for the primary outcome of tracheostomy. Data were analyzed with JMP (SAS Institute, Inc. Cary NC). We utilized GraphPad Prism (GraphPad Software, Inc. La Jolla CA) for all visual graphics. 2. Results 2.1. Patient characteristics The study population consisted of 90 patients with multisystem trauma. Of these, 17 patients received prehospital supraglottic rescue airway insertion and 73 BVM with subsequent inpatient ETI. Inadequate oxygenation and ventilation were demonstrated more frequently in patients that required supraglottic rescue airway (75%) compared to BVM (41%), p = 0.01. Table 1 presents patient demographics, admission vital signs, and measures of trauma severity between the supraglottic rescue airway and BVM groups. Sixty percent of patients were male. Between prehospital airway groups, patients that received a supraglottic rescue airway demonstrated increased head AIS scores compared to those receiving BVM (median [IQR]: 5 [4-5] versus 2 [0–4]. p = 0.001). Similarly, facial AIS scores were increased in patients receiving supraglottic rescue airways (median [IQR]: 1 [0–2]) compared to those with BVM (0 [0–0]), p = 0.03). Finally, patients that received BVM demonstrated increased rates of tachycardia compared to those managed with prehospital supraglottic rescue airways (p = 0.01). There were no significant differences between prehospital airway groups for patient sex, age, blunt traumatic mechanism, transport duration, cervical AIS, oxygen saturation at admission, respiratory rate, systolic or diastolic blood pressure. a. Prehospital airway outcomes Among the 17 patients, the indications for supraglottic rescue airway were multiple failed intubation attempts (n = 12) and multiple failed attempts with poor visualization (n = 5). Two cases of craniofacial trauma and three cases oropharyngeal trauma specifically affected airway visualization and thus prevented the successful placement of an endotracheal tube, leading to the insertion of a supraglottic airway device. In patients that received a prehospital supraglottic rescue airway, the overall median number of prehospital attempts at endotracheal intubation was 2 [1-3]. There was a significant increase in the median number of prehospital attempts at endotracheal intubation in patients who received surgical tracheostomy compared to endotracheal tube intubation (3 versus 2, p = 0.01). Conversely, no patient receiving BVM (n = 73) had an attempt at ETI; none of these patients experienced a prehospital airway related complication. At admission to the trauma resuscitation bay, the indications for ETI were copious vomiting in 3 patients and decreased Glasgow coma score (b 8) in the remaining 70 patients. 2.2. Definitive airway and overall outcomes After prehospital transport, all patients were evaluated by a multidisciplinary trauma team in the resuscitation bay per our institutional protocol (Fig. 1). The rate of tracheostomy was increased in patients with prehospital supraglottic rescue airway compared to those with BVM and inpatient ETI (31% versus 8%, p = 0.02). The patients that required tracheostomy after BVM and inpatient ETI (n = 3) were because of prolonged ventilator requirements. The twenty-four hour mortality was increased in patients with supraglottic rescue airways compared to BVM (38% versus 10.8%, p = 0.01). The overall mortality rate was dramatically increased in patients receiving prehospital supraglottic rescue airway (75%) compared to BVM (14%) p = 0.0001, Table 2. The causes of mortality between prehospital airway groups are outlined in Table 3. There were three cases of subglottic narrowing diagnosed via laryngoscopy in patients that received BVM and subsequent inpatient ETI. There
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M.C. Hernandez et al. / Journal of Pediatric Surgery 53 (2018) 352–356
Fig. 1. Institutional prehospital transport airway management algorithm (after first failed attempt).
were no significant differences in intensive care duration of stay or ventilator days between prehospital airway groups, Table 2. There was, however, an increased duration of total stay in patients that received BVM with subsequent inpatient ETI compared to prehospital supraglottic rescue airway insertion (median [IQR]: 6 [3–14] versus 4 [1–6], p = 0.01), which is expected given the lower mortality rate for this group. Table 4 reports independent risk factors for requiring surgical tracheostomy after prehospital airway interventions. Placement of a supraglottic rescue airway, increased number of attempts at ETI in the
prehospital setting, and an elevated (≥ 3) facial AIS were all independently associated with the use of surgical tracheostomy as a definitive airway (p b 0.05). When combined, this group of predictors produced an R2 of 0.73, explaining 73% of the variation in tracheostomy risk. 3. Discussion This study represents the first comparison of prehospital supraglottic rescue airways and bag valve mask ventilation among pediatric trauma
M.C. Hernandez et al. / Journal of Pediatric Surgery 53 (2018) 352–356
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Table 1 Patient characteristics in those receiving prehospital airway interventions; values are reported as medians with [interquartile range] unless specified. Variable
All (n = 90)
Supraglottic (n = 17)
BVM (n = 73)
P value
Sex, female, n (%) Age Blunt n (%) Transport duration (minutes) ISS Head AIS Face AIS Cervical AIS Glasgow Coma Score Oxygen Saturation Partial Pressure Carbon Dioxide RR HR SBP DBP
36 (40) 14 [4–17] 79 (88) 26 [15–41] 26 [19–34] 3 [0–5] 0 [0–1] 0 [0–0] 4 [3–7] 99 [90–100] 42 [36–49] 22 [18–26] 111 [88–129] 113 [93–132] 69 [58–83]
3 (18) 16 [10–17] 12 (75) 24 [12–33] 28 [25–44] 5 [4–5] 1 [0–2] 0 [0–0] 3 [3–3] 93 [71–93] 46 [42–50] 19 [16–26] 90 [48–114] 98 [72–121] 68 [25–73]
32 (43) 13 [4–17] 67 (91) 27 [17–42] 26 [17–34] 2 [0–4] 0 [0–0] 0 [0–0] 3 [3–5] 99 [94–100] 41 [36–48] 23 [19–26] 112 [91–130] 115 [97–134] 71 [58–84]
0.06 0.4 0.2 0.4 0.1 0.001 0.03 0.5 0.1 0.1 0.3 0.1 0.01 0.1 0.2
patients. We highlight the specific challenges, potential prehospital airway complications, and important clinical outcomes among patients receiving supraglottic airway insertion. While both groups in this study displayed similar overall injury patterns, the need for tracheostomy was increased in patients with increased craniofacial injury patterns. Specifically, increased craniofacial injury scores reflected by AIS N 3 in the head, face, and neck; the number of attempts at endotracheal intubation prior to supraglottic airway deployment; and utilization of a supraglottic rescue airway all predicted definitive airway management using surgical tracheostomy. The combination of these factors explained nearly three fourths of the variation in subsequent tracheostomy placement. Moreover, both prehospital BVM ventilation and supraglottic rescue airway demonstrate inadequate oxygenation or ventilation at time of admission (40%–75%). This was increased in patients that received supraglottic rescue airways compared to BVM ventilation. Beyond these results, this analysis provides an initial exploratory query into the role of adjunct airways, the complication profile, and subsequent definitive airway management in the pediatric trauma population. Airway assessment and control are a primary objective during trauma resuscitation [21]. In the setting of a supraglottic airway and trauma, minimal evidence exists to guide definitive airway management for children and adolescents [12,22]. One recent analysis evaluating adults with supraglottic airways found that an overwhelming majority of patients had their supraglottic airway exchanged for an endotracheal tube [23]. However, the majority of these patients underwent medical resuscitations, not necessarily trauma. The mixture of trauma and medical resuscitation patients complicates the identification of optimal methods for definitive airways after supraglottic airway utilization. A strength of this analysis is that our cohort is restricted to multisystem pediatric trauma patients. Our findings will play an important role guiding prehospital transport, the goal of which is preventing further injury and expediting transport to definitive care [24]. Airway adjuncts, such as the King LT™, provide temporary restoration of oxygenation and ventilation for
Table 2 Comparison of outcomes by prehospital airway type; values are reported as medians with [interquartile range] unless specified. Variable Overall Duration of Stay (d) Mechanical Ventilation (d) ICU duration of stay (d) 24 h mortality n (%) Overall mortality n (%) Tracheostomy n (%) Subglottic/tracheal stenosis n (%)
Supraglottic airway (n = 17) 4 [1–6] 2 [1–4] 3 [1–5] 6 (38) 12 (75) 5 (31) 1 (5.9)
BVM ventilation (n = 73) 6 [3–14] 2 [1–2] 2 [1–7] 8 (10.8) 10 (14) 6 (8.1) 3 (4.1)
P value 0.01 0.4 0.4 0.01 0.0001 0.01 0.08
difficult airway patients [3–6,25,26]. Previous work demonstrates inferior outcomes of endotracheal intubation compared to bag valve mask oxygenation in pediatric patients [27–30]. These findings were further confirmed demonstrating that patients with intubation did not display superior outcomes compared to BVM patients [7]. Despite this literature, some patients will require advanced airway care in the prehospital setting [1]. Our study confirms that for some multisystem pediatric trauma patients, the standard of care (BVM) may not safely provide airway control, necessitating placement of a supraglottic device. While the prehospital setting provides airway control and triaged interventions, definitive care and focused management according the Advanced Trauma Life Support protocols are the critical next step. An actionable definitive airway plan must be defined and executed amidst multiple organ system priorities. Since definitive airway management is poorly understood, especially in pediatric trauma patients, this current investigation provides useful preliminary data to suggest further analyses. This comparison of similarly injured patients with airway control provided by prehospital BVM versus supraglottic airway insertion found that increased craniofacial injury, prehospital ETI attempts, and need for supraglottic rescue airway were all independently associated with later surgical tracheostomy as a definitive airway. This analysis provides evidence to suggest that a prospective analysis of appropriate pediatric definitive airway management after supraglottic device insertion is needed. Recognition of patients who require advanced airway management and definitive airway control with a surgical airway may prevent unnecessary placement of tracheostomy and permit more individualized decision-making for patients requiring supraglottic rescue airways [31]. There are several limitations to this study. This is a retrospective single institutional study focusing on small but specific subset of pediatric patients. Only one device, the King LT, was used and may not be equivalent to a laryngeal mask airway. Anecdotally, the EMS practice has shifted to use of the i-Gel (Intersurgical, East Syracuse, New York) with no attempts at ETI, which may decrease the additional trauma to the airway (verbal communication). Review of these other devices and comparison of different supraglottic devices in this clinical context would add to our understanding of best practices for pediatric airway management in the trauma patient and may change institutional prehospital algorithms. Future research is necessary to confirm these findings through a more controlled analysis. Despite these limitations, Table 3 Causes of mortality between prehospital airway intervention groups. Variable
Supraglottic airway
BVM ventilation
Traumatic Brain Injury Hemorrhagic Shock/Exsanguination Respiratory Failure owing to Pneumonia
7 4 1
7 3 0
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M.C. Hernandez et al. / Journal of Pediatric Surgery 53 (2018) 352–356
Table 4 Risk factors independently associated with need for surgical tracheostomy after prehospital airway interventions.
Number of prehospital failed endotracheal intubation attempts Cervical AIS ≥3 Facial AIS ≥3 Head AIS ≥3 Supraglottic Rescue Airway Insertion
OR
95% CI
p-value
McFadden's R2
1.2
1.1, 1.5
0.03
0.73
1.8 2.2 1.4 1.4
0.9, 4.1 1.5, 3.6 0.8,1.9 1.1,1.8
0.30 0.02 0.60 0.02
Abbreviations: CI, Confidence Interval; AIS, Abbreviated Injury Score OR, Odds Ratio.
these findings serve as preliminary data for future analyses and provide the first structured information specific to supraglottic airway use in injured children. At our institution, older adolescents (15–17 year olds) are managed by the adult trauma team, which has developed a practice of early tracheostomy in patients presenting with supraglottic devices. These cases are reviewed and decisions about exchange versus tracheostomy are made in a collaborative fashion in the trauma bay. This number was too small to merit a separate analysis. Thus, our data for this subgroup demonstrate selection bias based on clinical judgment — patients with perceived risk factors for difficult airways were managed more frequently with surgical airways. However, a prospective, randomized comparison of surgical airway and ETT exchange is unlikely to ever be performed. 4. Conclusion Patients that received supraglottic rescue airways more frequently demonstrated inadequate oxygenation and/or ventilation at the time of admission compared to BVM as well as increased rates of mortality and definitive airway control with tracheostomy. Conversely, none of the BVM patients suffered from a prehospital airway complication. Nevertheless, our study confirms that for some multisystem pediatric trauma patients, the standard of care (BVM) may not safely provide airway control, necessitating placement of a supraglottic device. Patients who require prehospital supraglottic rescue airways represent a unique decision-making challenge during the initial trauma resuscitation. Patient factors such as distorted or injured anatomy, as well as EMS factors such as number of previous intubation attempts, should influence the route of definitive airway management after supraglottic device use. Acknowledgments This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Author contributions: Study Design: MCH, RMA, KB, DBK. Data acquisition, analysis, or interpretation: MCH, RMA, MDZ, KB, DBK. Drafting: MCH, RMA, KB, DBK. Final approval: MCH, RMA, MDZ, KB, DBK. References [1] Article S. 2005 American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care (ECC) of pediatric and neonatal patients: neonatal resuscitation guidelines. Pediatrics 2006;117(5):e1029-8. [2] Mitchell MS, Lee White M, King WD, et al. Paramedic king laryngeal tube airway insertion versus endotracheal intubation in simulated pediatric respiratory arrest. Prehosp Emerg Care 2012;16(2):284–8.
[3] Guyette FX, Wang H, Cole JS. King airway use by air medical providers. Prehosp Emerg Care 2007;11(4):473–6. [4] Frascone RJ, Wewerka SS, Griffith KR, et al. Use of the King LTS-D during medicationassisted airway management. Prehosp Emerg Care 2009;13(4):541–5. [5] Hubble MW, Brown L, Wilfong DA, et al. A meta-analysis of pre-hospital airway control techniques part I: orotracheal and nasotracheal intubation success rates. Prehosp Emerg Care 2010;14(3):377–401. [6] Link MS, Berkow LC, Kudenchuk PJ, et al. Part 7: adult advanced cardiovascular life support: 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation 2015;132(18): S444–64. [7] Gausche M, Lewis RJ, Stratton SJ, et al. Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome. JAMA 2000;283(6):783. [8] Davis DP, Hoyt DB, Ochs M, et al. The effect of paramedic rapid sequence intubation on outcome in patients with severe traumatic brain injury. J Trauma 2003;54(3): 444–53. [9] Ehrlich PF, Seidman PS, Atallah O, et al. Endotracheal intubations in rural pediatric trauma patients. J Pediatr Surg 2004;39(9):1376–80. [10] DiRusso SM, Sullivan T, Risucci D, et al. Intubation of pediatric trauma patients in the field: predictor of negative outcome despite risk stratification. J Trauma 2005;59(1): 84–91. [11] Sokol KK, Black GE, Azarow KS, et al. Pre-hospital interventions in severely injured pediatric patients. J Trauma Acute Care Surg 2015;79(6):983–90. [12] Prekker ME, Delgado F, Shin J, et al. Pediatric intubation by paramedics in a large emergency medical services system: process, challenges, and outcomes. Ann Emerg Med 2016;67(1):20–9. [13] Wamg HE, Kupas DF, Greenwood MJ, et al. An algorithmic approach to pre-hospital airway management. Prehosp Emerg Care 2005;9(2):145–55. [14] Warner KJ, Sharar SR, Copass MK, et al. Pre-hospital management of the difficult airway: a prospective cohort study. J Emerg Med 2009;36(3):257–65. [15] Gerber MA, Shulman ST, Byars DV, et al. Comparison of direct laryngoscopy to pediatric king LT-D in simulated airways. Pediatr Emerg Care 2012;28(8): 750–2. [16] Gaither JB, Matheson J, Eberhardt A, et al. Tongue engorgement associated with prolonged use of the king-LT laryngeal tube device. Ann Emerg Med 2010;55(4): 367–9. [17] Lutes M, Worman DJ. An unanticipated complication of a novel approach to airway management. J Emerg Med 2010;38(2):222–4. [18] Schalk R, Seeger FH, Mutlak H, et al. Complications associated with the pre-hospital use of laryngeal tubes—a systematic analysis of risk factors and strategies for prevention. Resuscitation 2014;85(11):1629–32. [19] Khaja SF, Chang KE. Airway algorithm for the management of patients with a King LT. Laryngoscope 2014;124(5):1123–7. 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Contents lists available at ScienceDirect
Journal of Pediatric Surgery journal homepage: www.elsevier.com/locate/jpedsurg
Definitive airway management after prehospital supraglottic rescue airway in pediatric trauma☆ Matthew C. Hernandez b, Ryan M. Antiel a, Karthik Balakrishnan c, Martin D. Zielinski b, Denise B. Klinkner a,⁎ a b c
Department of Pediatric Surgery, Mayo Clinic, Rochester, MN Department of Trauma, Critical Care and General Surgery, Mayo Clinic, Rochester, MN Department of Otolaryngology, Mayo Clinic, Rochester, MN
a r t i c l e
i n f o
Article history: Received 3 October 2017 Accepted 4 October 2017 Key words: Supraglottic airway Trauma Pediatric Prehospital ATLS
a b s t r a c t Introduction: Supraglottic airway (SGA) use and outcomes in pediatric trauma are poorly understood. We compared outcomes between patients receiving prehospital SGA versus bag mask ventilation (BVM). Methods: We reviewed pediatric multisystem trauma patients (2005–2016), comparing SGA and BVM. Primary outcome was adequacy of oxygenation and ventilation. Additional measures included tracheostomy, mortality and abbreviated injury scores (AIS). Results: Ninety patients were included (SGA, n = 17 and BVM, n = 73). SGA patients displayed increased median head AIS (5 [4–5] vs 2 [0–4], p = 0.001) and facial AIS (1 [0–2] vs 0 [0–0], p = 0.03). SGA indications were multiple failed intubation attempts (n = 12) and multiple failed attempts with poor visualization (n = 5). Median intubation attempts were 2 [1–3] whereas BVM patients had none. Compared to BVM, SGA patients demonstrated inadequate oxygenation/ventilation (75% vs 41%), increased tracheostomy rates (31% vs 8.1%), and increased 24-h (38% vs 10.8%) and overall mortality (75% vs 14%) (all p b 0.05). Conclusions: Escalating intubation attempts and severe facial AIS were associated with tracheostomy. Inadequacy of oxygenation/ventilation was more frequent in SGA compared to BVM patients. SGA patients demonstrate poor clinical outcomes; however, SGAs may be necessary in increased craniofacial injury patterns. These factors may be incorporated into a management algorithm to improve definitive airway management after SGA. © 2017 Elsevier Inc. All rights reserved.
Inadequate airway management may lead to cardiovascular arrest and complicate subsequent life-saving interventions in the injured patient [1]. Several airway control devices and techniques are available to assist prehospital providers in order to maintain ventilation and oxygenation. These include bag valve mask (BVM) ventilation, direct laryngoscopy with endotracheal intubation (ETI) and adjunct supraglottic airway devices such as the laryngeal mask airway, Combitube, and King Airway Device (King LT-D; King Systems, Noblesville, IN) [2]. Despite the variety of options available to secure the airway, there is a paucity of data evaluating the outcomes of supraglottic rescue airway devices, especially in pediatric trauma. In the pediatric population, prehospital airway interventions may not be superior to BVM ventilation. Previous work has demonstrated moderate prehospital ETI failure rates with subsequent tube malposition [7–11]. These studies concluded that prehospital pediatric ☆ The authors have no financial conflicts for the generation of this work. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. ⁎ Corresponding author at: Mayo Clinic, 200 First Street SW, Rochester, MN 55905. E-mail addresses: [email protected] (M.C. Hernandez), [email protected] (R.M. Antiel), [email protected] (K. Balakrishnan), [email protected] (M.D. Zielinski), [email protected] (D.B. Klinkner). https://doi.org/10.1016/j.jpedsurg.2017.10.004 0022-3468/© 2017 Elsevier Inc. All rights reserved.
advanced airway interventions may not be necessary to achieve adequate ventilation/oxygenation while also recognizing that a proportion of patients may require advanced airway control maneuvers, including supraglottic rescue airway insertion. Supraglottic rescue airway devices may provide an alternative method to achieve airway control. Currently, no studies (1) describe supraglottic rescue airway utilization in pediatric trauma patients or (2) compare this adjunct to the standard of care (BVM). This makes it difficult to estimate how these devices might affect airway and trauma outcomes [12]. Supraglottic rescue airways provide more facile airway control for difficult airway patients. However, they are not without risk and may have size limitations in smaller pediatric patients [2,13–15]. Complications from insertion range from malposition to dislodgement [16–18]. Furthermore, the optimal method for safe transition to a definitive airway and the most appropriate definitive airway type have yet to be determined [19,20]. Therefore, the objective of this study is to compare outcomes, specifically adequacy of oxygenation and/or ventilation at time of admission among pediatric patients who received prehospital supraglottic airways versus BVM ventilation. We hypothesize that patients with increased craniofacial injury patterns and difficult airways in the prehospital setting would be more likely to require advanced airway techniques, including surgical tracheostomy, as a definitive airway.
M.C. Hernandez et al. / Journal of Pediatric Surgery 53 (2018) 352–356
1. Methods 1.1. Patient identification This study was approved by the Mayo Clinic Institutional Review Board. We performed a single center retrospective study that examined patients who were ≤18 years old and incurred multisystem trauma during 2005–2016. Multisystem trauma was defined as an Injury Severity Score of ≥9. Patients were identified from the Mayo Clinic Trauma Center database for (1) insertion of a supraglottic rescue airway (King Airway Device, King LT-D, Noblesville, IN) or (2) prehospital bag valve mask ventilation (BVM) with subsequent endotracheal intubation (ETI) in the resuscitation bay after airway evaluation. Patients who received endotracheal intubation in the prehospital setting, received a supraglottic rescue airway device other than a King LT-D, refused consent to research, and who did not display multisystem trauma (ISS b9) were excluded. 1.2. Institutional prehospital airway care Patients were transported by rotor wing or via ground transportation. Patients that were transported by rotor wing received care from critical care trained flight nurses. Patients that were transported via ground transportation received care from paramedics. At our institution, injured patients that require advanced prehospital airway management meet criteria for our highest level trauma team activation. Emergency Medicine, Surgery, and Anesthesia physicians are present in the trauma resuscitation bay at patient arrival. For patients ≤ 14 years of age, the pediatric surgeon responds within 15 min, and the pediatric critical care physician also responds. Each prehospital airway intervention is reviewed in detail by the directors of Medical Transportation, Emergency Medicine, Trauma Surgery, and Anesthesia. A prehospital advanced airway control algorithm has been defined and implemented by this group for standardized practice and safe patient care. See Fig. 1. 1.3. Primary outcome and secondary predictors Primary outcome was adequacy of oxygenation and ventilation at the time of hospital arrival. Inadequate oxygenation saturation was defined as (b 92%) using pulse oximetry or a partial pressure of carbon dioxide (PCO2) of (N 45 mmHg) using arterial blood gas. Secondary outcomes included need for tracheostomy, mortality and abbreviated injury scores (AIS). Patient demographics, transportation method and duration, traumatic mechanism, trauma severity (ISS and abbreviated injury scores (AIS)), admission vital signs (heart rate, respiratory rate, systolic and diastolic blood pressure and oxygen saturation), Glasgow Coma Score (GCS), 24 h and overall mortality, frequency and type of prehospital airway complications, and number of prehospital airway attempts, durations of intensive care, mechanical ventilation and overall hospital stay were abstracted from the electronic record. 1.4. Statistical analyses Summary statistical and univariate analyses were performed. Continuous variables were described using means with standard deviations (SD) if normally distributed and medians with interquartile ranges [IQR] for non-normally distributed data. Two-tailed t-tests were performed between prehospital airway groups (supraglottic rescue airway versus BVM with subsequent inpatient ETI). In order to assess which factors were associated with an increased need for surgical definitive airway (open tracheostomy), logistic nominal regression was applied to statistically significant and clinically important variables. Categorical variables were summarized as proportions, and differences were evaluated using chi-square analysis. Statistical inferences were based on 2tailed tests with significance set at P b 0.05. All patients meeting
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inclusion criteria were included in the analysis; a priori power analysis was not performed owing to lack of data to suggest an appropriate effect size for the primary outcome of tracheostomy. Data were analyzed with JMP (SAS Institute, Inc. Cary NC). We utilized GraphPad Prism (GraphPad Software, Inc. La Jolla CA) for all visual graphics. 2. Results 2.1. Patient characteristics The study population consisted of 90 patients with multisystem trauma. Of these, 17 patients received prehospital supraglottic rescue airway insertion and 73 BVM with subsequent inpatient ETI. Inadequate oxygenation and ventilation were demonstrated more frequently in patients that required supraglottic rescue airway (75%) compared to BVM (41%), p = 0.01. Table 1 presents patient demographics, admission vital signs, and measures of trauma severity between the supraglottic rescue airway and BVM groups. Sixty percent of patients were male. Between prehospital airway groups, patients that received a supraglottic rescue airway demonstrated increased head AIS scores compared to those receiving BVM (median [IQR]: 5 [4-5] versus 2 [0–4]. p = 0.001). Similarly, facial AIS scores were increased in patients receiving supraglottic rescue airways (median [IQR]: 1 [0–2]) compared to those with BVM (0 [0–0]), p = 0.03). Finally, patients that received BVM demonstrated increased rates of tachycardia compared to those managed with prehospital supraglottic rescue airways (p = 0.01). There were no significant differences between prehospital airway groups for patient sex, age, blunt traumatic mechanism, transport duration, cervical AIS, oxygen saturation at admission, respiratory rate, systolic or diastolic blood pressure. a. Prehospital airway outcomes Among the 17 patients, the indications for supraglottic rescue airway were multiple failed intubation attempts (n = 12) and multiple failed attempts with poor visualization (n = 5). Two cases of craniofacial trauma and three cases oropharyngeal trauma specifically affected airway visualization and thus prevented the successful placement of an endotracheal tube, leading to the insertion of a supraglottic airway device. In patients that received a prehospital supraglottic rescue airway, the overall median number of prehospital attempts at endotracheal intubation was 2 [1-3]. There was a significant increase in the median number of prehospital attempts at endotracheal intubation in patients who received surgical tracheostomy compared to endotracheal tube intubation (3 versus 2, p = 0.01). Conversely, no patient receiving BVM (n = 73) had an attempt at ETI; none of these patients experienced a prehospital airway related complication. At admission to the trauma resuscitation bay, the indications for ETI were copious vomiting in 3 patients and decreased Glasgow coma score (b 8) in the remaining 70 patients. 2.2. Definitive airway and overall outcomes After prehospital transport, all patients were evaluated by a multidisciplinary trauma team in the resuscitation bay per our institutional protocol (Fig. 1). The rate of tracheostomy was increased in patients with prehospital supraglottic rescue airway compared to those with BVM and inpatient ETI (31% versus 8%, p = 0.02). The patients that required tracheostomy after BVM and inpatient ETI (n = 3) were because of prolonged ventilator requirements. The twenty-four hour mortality was increased in patients with supraglottic rescue airways compared to BVM (38% versus 10.8%, p = 0.01). The overall mortality rate was dramatically increased in patients receiving prehospital supraglottic rescue airway (75%) compared to BVM (14%) p = 0.0001, Table 2. The causes of mortality between prehospital airway groups are outlined in Table 3. There were three cases of subglottic narrowing diagnosed via laryngoscopy in patients that received BVM and subsequent inpatient ETI. There
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Fig. 1. Institutional prehospital transport airway management algorithm (after first failed attempt).
were no significant differences in intensive care duration of stay or ventilator days between prehospital airway groups, Table 2. There was, however, an increased duration of total stay in patients that received BVM with subsequent inpatient ETI compared to prehospital supraglottic rescue airway insertion (median [IQR]: 6 [3–14] versus 4 [1–6], p = 0.01), which is expected given the lower mortality rate for this group. Table 4 reports independent risk factors for requiring surgical tracheostomy after prehospital airway interventions. Placement of a supraglottic rescue airway, increased number of attempts at ETI in the
prehospital setting, and an elevated (≥ 3) facial AIS were all independently associated with the use of surgical tracheostomy as a definitive airway (p b 0.05). When combined, this group of predictors produced an R2 of 0.73, explaining 73% of the variation in tracheostomy risk. 3. Discussion This study represents the first comparison of prehospital supraglottic rescue airways and bag valve mask ventilation among pediatric trauma
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Table 1 Patient characteristics in those receiving prehospital airway interventions; values are reported as medians with [interquartile range] unless specified. Variable
All (n = 90)
Supraglottic (n = 17)
BVM (n = 73)
P value
Sex, female, n (%) Age Blunt n (%) Transport duration (minutes) ISS Head AIS Face AIS Cervical AIS Glasgow Coma Score Oxygen Saturation Partial Pressure Carbon Dioxide RR HR SBP DBP
36 (40) 14 [4–17] 79 (88) 26 [15–41] 26 [19–34] 3 [0–5] 0 [0–1] 0 [0–0] 4 [3–7] 99 [90–100] 42 [36–49] 22 [18–26] 111 [88–129] 113 [93–132] 69 [58–83]
3 (18) 16 [10–17] 12 (75) 24 [12–33] 28 [25–44] 5 [4–5] 1 [0–2] 0 [0–0] 3 [3–3] 93 [71–93] 46 [42–50] 19 [16–26] 90 [48–114] 98 [72–121] 68 [25–73]
32 (43) 13 [4–17] 67 (91) 27 [17–42] 26 [17–34] 2 [0–4] 0 [0–0] 0 [0–0] 3 [3–5] 99 [94–100] 41 [36–48] 23 [19–26] 112 [91–130] 115 [97–134] 71 [58–84]
0.06 0.4 0.2 0.4 0.1 0.001 0.03 0.5 0.1 0.1 0.3 0.1 0.01 0.1 0.2
patients. We highlight the specific challenges, potential prehospital airway complications, and important clinical outcomes among patients receiving supraglottic airway insertion. While both groups in this study displayed similar overall injury patterns, the need for tracheostomy was increased in patients with increased craniofacial injury patterns. Specifically, increased craniofacial injury scores reflected by AIS N 3 in the head, face, and neck; the number of attempts at endotracheal intubation prior to supraglottic airway deployment; and utilization of a supraglottic rescue airway all predicted definitive airway management using surgical tracheostomy. The combination of these factors explained nearly three fourths of the variation in subsequent tracheostomy placement. Moreover, both prehospital BVM ventilation and supraglottic rescue airway demonstrate inadequate oxygenation or ventilation at time of admission (40%–75%). This was increased in patients that received supraglottic rescue airways compared to BVM ventilation. Beyond these results, this analysis provides an initial exploratory query into the role of adjunct airways, the complication profile, and subsequent definitive airway management in the pediatric trauma population. Airway assessment and control are a primary objective during trauma resuscitation [21]. In the setting of a supraglottic airway and trauma, minimal evidence exists to guide definitive airway management for children and adolescents [12,22]. One recent analysis evaluating adults with supraglottic airways found that an overwhelming majority of patients had their supraglottic airway exchanged for an endotracheal tube [23]. However, the majority of these patients underwent medical resuscitations, not necessarily trauma. The mixture of trauma and medical resuscitation patients complicates the identification of optimal methods for definitive airways after supraglottic airway utilization. A strength of this analysis is that our cohort is restricted to multisystem pediatric trauma patients. Our findings will play an important role guiding prehospital transport, the goal of which is preventing further injury and expediting transport to definitive care [24]. Airway adjuncts, such as the King LT™, provide temporary restoration of oxygenation and ventilation for
Table 2 Comparison of outcomes by prehospital airway type; values are reported as medians with [interquartile range] unless specified. Variable Overall Duration of Stay (d) Mechanical Ventilation (d) ICU duration of stay (d) 24 h mortality n (%) Overall mortality n (%) Tracheostomy n (%) Subglottic/tracheal stenosis n (%)
Supraglottic airway (n = 17) 4 [1–6] 2 [1–4] 3 [1–5] 6 (38) 12 (75) 5 (31) 1 (5.9)
BVM ventilation (n = 73) 6 [3–14] 2 [1–2] 2 [1–7] 8 (10.8) 10 (14) 6 (8.1) 3 (4.1)
P value 0.01 0.4 0.4 0.01 0.0001 0.01 0.08
difficult airway patients [3–6,25,26]. Previous work demonstrates inferior outcomes of endotracheal intubation compared to bag valve mask oxygenation in pediatric patients [27–30]. These findings were further confirmed demonstrating that patients with intubation did not display superior outcomes compared to BVM patients [7]. Despite this literature, some patients will require advanced airway care in the prehospital setting [1]. Our study confirms that for some multisystem pediatric trauma patients, the standard of care (BVM) may not safely provide airway control, necessitating placement of a supraglottic device. While the prehospital setting provides airway control and triaged interventions, definitive care and focused management according the Advanced Trauma Life Support protocols are the critical next step. An actionable definitive airway plan must be defined and executed amidst multiple organ system priorities. Since definitive airway management is poorly understood, especially in pediatric trauma patients, this current investigation provides useful preliminary data to suggest further analyses. This comparison of similarly injured patients with airway control provided by prehospital BVM versus supraglottic airway insertion found that increased craniofacial injury, prehospital ETI attempts, and need for supraglottic rescue airway were all independently associated with later surgical tracheostomy as a definitive airway. This analysis provides evidence to suggest that a prospective analysis of appropriate pediatric definitive airway management after supraglottic device insertion is needed. Recognition of patients who require advanced airway management and definitive airway control with a surgical airway may prevent unnecessary placement of tracheostomy and permit more individualized decision-making for patients requiring supraglottic rescue airways [31]. There are several limitations to this study. This is a retrospective single institutional study focusing on small but specific subset of pediatric patients. Only one device, the King LT, was used and may not be equivalent to a laryngeal mask airway. Anecdotally, the EMS practice has shifted to use of the i-Gel (Intersurgical, East Syracuse, New York) with no attempts at ETI, which may decrease the additional trauma to the airway (verbal communication). Review of these other devices and comparison of different supraglottic devices in this clinical context would add to our understanding of best practices for pediatric airway management in the trauma patient and may change institutional prehospital algorithms. Future research is necessary to confirm these findings through a more controlled analysis. Despite these limitations, Table 3 Causes of mortality between prehospital airway intervention groups. Variable
Supraglottic airway
BVM ventilation
Traumatic Brain Injury Hemorrhagic Shock/Exsanguination Respiratory Failure owing to Pneumonia
7 4 1
7 3 0
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Table 4 Risk factors independently associated with need for surgical tracheostomy after prehospital airway interventions.
Number of prehospital failed endotracheal intubation attempts Cervical AIS ≥3 Facial AIS ≥3 Head AIS ≥3 Supraglottic Rescue Airway Insertion
OR
95% CI
p-value
McFadden's R2
1.2
1.1, 1.5
0.03
0.73
1.8 2.2 1.4 1.4
0.9, 4.1 1.5, 3.6 0.8,1.9 1.1,1.8
0.30 0.02 0.60 0.02
Abbreviations: CI, Confidence Interval; AIS, Abbreviated Injury Score OR, Odds Ratio.
these findings serve as preliminary data for future analyses and provide the first structured information specific to supraglottic airway use in injured children. At our institution, older adolescents (15–17 year olds) are managed by the adult trauma team, which has developed a practice of early tracheostomy in patients presenting with supraglottic devices. These cases are reviewed and decisions about exchange versus tracheostomy are made in a collaborative fashion in the trauma bay. This number was too small to merit a separate analysis. Thus, our data for this subgroup demonstrate selection bias based on clinical judgment — patients with perceived risk factors for difficult airways were managed more frequently with surgical airways. However, a prospective, randomized comparison of surgical airway and ETT exchange is unlikely to ever be performed. 4. Conclusion Patients that received supraglottic rescue airways more frequently demonstrated inadequate oxygenation and/or ventilation at the time of admission compared to BVM as well as increased rates of mortality and definitive airway control with tracheostomy. Conversely, none of the BVM patients suffered from a prehospital airway complication. Nevertheless, our study confirms that for some multisystem pediatric trauma patients, the standard of care (BVM) may not safely provide airway control, necessitating placement of a supraglottic device. Patients who require prehospital supraglottic rescue airways represent a unique decision-making challenge during the initial trauma resuscitation. Patient factors such as distorted or injured anatomy, as well as EMS factors such as number of previous intubation attempts, should influence the route of definitive airway management after supraglottic device use. Acknowledgments This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Author contributions: Study Design: MCH, RMA, KB, DBK. Data acquisition, analysis, or interpretation: MCH, RMA, MDZ, KB, DBK. Drafting: MCH, RMA, KB, DBK. Final approval: MCH, RMA, MDZ, KB, DBK. References [1] Article S. 2005 American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care (ECC) of pediatric and neonatal patients: neonatal resuscitation guidelines. Pediatrics 2006;117(5):e1029-8. [2] Mitchell MS, Lee White M, King WD, et al. Paramedic king laryngeal tube airway insertion versus endotracheal intubation in simulated pediatric respiratory arrest. Prehosp Emerg Care 2012;16(2):284–8.
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