Airway Management in the Pediatric Trauma Patient
- Mar 16th, 2020
- Joe Ravera
Author: Joe Ravera, MD (@pemuvm1, Director of Pediatric Emergency Medicine, Assistant Professor of Surgery, Division of Emergency Medicine, University of Vermont Medical Center) // Reviewed by: Edward Lew, MD (@elewMD); Alex Koyfman, MD (@EMHighAK); Skyler Lentz, MD (@skylerlentz); Brit Long, MD (@long_brit)
1) A 4-year-old child presents after falling from a second story window. He has a GCS of 4 and the decision is made to intubate for airway protection.
What would be the appropriate size DL blade? What would be the appropriately sized ET tube? Should it be a cuffed or uncuffed tube? How can we rapidly assess his weight for medication doses and what medication should be used for induction and paralysis?
2) A 10-year-old child is struck by a motor vehicle and presents with obvious severe head trauma and a GCS of 3. The decision is made to intubate the patient for airway protection.
Which two adverse events should be minimized if at all possible during intubation to prevent secondary brain injury? What strategies could possibly be used to minimize complications, specifically hypoxia?
3) A 9-year-old child with a history of Treacher-Collins syndrome presents as an unrestrained passenger after a severe motor vehicle accident. The patient has had known difficult intubations in the past. The patient is obtunded and requires emergent intubation.
What equipment should be available to help facilitate visualization on laryngoscopy? What equipment should be available if an ET tube is unable to be secured with laryngoscopy?
Pediatric airway management, particularly in centers that do not typically see a high volume of pediatric patients, can be a very stressful and anxiety producing situation for the providers involved. Moreover, trauma airways are by definition, difficult airways, and pediatric patients present unique challenges due to changing anatomy and physiology. The purpose of this review is to:
- Understand the pediatric airway as a dynamic structure that changes with age
- Understand pediatric physiology as it relates to airway management
- Review appropriately sized equipment and medication considerations
- Discuss special considerations related to pediatric head trauma
- Highlight some clinical pearls and pitfalls
The pediatric airway changes drastically in the first several years of life. By the age of 8 the airway is fairly mature and similar to an adult airway; however, younger children, particularly under 1 year, can present difficulties due to anatomic differences. These include large occiputs that limit extension, redundant tissue, and an anterior airway that can make visualization difficult. In smaller children, optimal patient positioning can be aided by placing a roll under the shoulders, which may improve visualization on laryngoscopy.
The principle difference in pediatric physiology as it relates to airway management involves patient oxygenation. Children, even adequately preoxygenated children, will desaturate much quicker than adults during a period of apnea. Moreover, children are extremely intolerant of prolonged hypoxia; this is of great concern particularly in the traumatic head injury patient where a single episode of hypoxia prognosticates worse outcome. To address these issues, children should be adequately preoxygenated prior to intubation as much as possible. Despite lack of evidence of benefit, given that there is little harm, apneic oxygenation with nasal cannula should be strongly considered during periods of paralysis and attempted laryngoscopy.1
Appropriate Airway Equipment
Selecting appropriate resuscitation equipment for a child, particularly in the middle of a major trauma, can present a challenge. In critical situations where obtaining a weight will delay care, use a length-based resuscitation tape to obtain an estimation of the patient’s weight. These products will often list appropriate sized airway equipment based on the child’s length and expected body weight (Figure 1). If this is unavailable, there are several quick formulas and mnemonics to help. When selecting a blade for direct laryngoscopy a “Miller 2 at 2 and 3 Blade at 3rd grade” are quick ways to remember benchmark ages and the appropriate blade size for those age groups. If available, video laryngoscopy can be used either primarily or as a back-up if direct laryngoscopy fails. The evidence shows that video laryngoscopy will improve cord visualization although there can be difficulty with passing an endotracheal tube.2,3 Visualization can be particularly difficult in young children and neonates, so familiarity with video-assisted laryngoscopy is strongly recommended as a skill for providers that will be performing pediatric intubations.
If not available from a length-based resuscitation tape, select an endotracheal tube with the formula: (Age/4) + 3.5 = cuffed endotracheal tube size
Proper preparation includes having one size above and below as a child’s anatomy can vary unexpectedly. Cuffed tubes are now recommended in all pediatric intubations.4
Unless the child is in cardiac arrest or extremis, endotracheal intubation most likely will require a sedative medication and paralysis. Although the use of sedative and paralytic medication for rapid sequence intubation in the emergency department is not universal practice, there is some evidence to suggest an association between sedation and paralysis leading to more first-pass success, particularly in trainees.3 Pretreatment with atropine, particularly in children less than a year, to avoid a reflex bradycardia has been recommended in the past when giving succinylcholine, although the evidence supporting its use is limited.5 Therefore, consider having atropine available but not routinely giving it prior to pediatric rapid sequence intubation.
There are several medication options for induction, all with various advantages and disadvantages. Given that in trauma patients we want to minimize hypotension, most clinicians will not use propofol (1-2mg/kg) or a combination of fentanyl (1-2ug/kg) and midazolam (0.1-0.3mg/kg) out of concern for hypotension. Etomidate (0.3 mg/kg) has been used successfully as it is more hemodynamically neutral.6 Although there is demonstrable adrenal suppression after a single dose of etomidate in pediatric patients, there is no data to suggest long-term changes in clinical outcome. Ketamine (2mg/kg) is a dissociative anesthetic that preserves airway reflexes and typically causes a reflex tachycardia and hypertension, which can be beneficial in trauma patients. Scherzer et. al provides a comprehensive review of the pros and cons of both ketamine and etomidate.7 Therefore, consider ketamine to be the primary induction agent of choice in pediatric trauma patients with the possible exception of pediatric head injury patients (see below).
A paralytic agent is often used to facilitate intubation. The mainstays are rocuronium (1.2 mg/kg) and succinylcholine (2mg/kg). Vecuronium is no longer preferred as prolonged paralysis post intubation can complicate neurologic examination. There is extensive debate about the proper paralytic agent to use; succinylcholine has a worse side effect profile but also has a rapid offset if a child is unable to be intubated.8,9 There is also a theoretical concern for succinylcholine with younger children, particularly males, of an undiagnosed muscular dystrophy causing hyperkalemia. With the advent sugammadex, a reversal agent for the nondepolarizing agents like rocuronium, one can rapidly reverse paralysis if unable to intubate the child or to facilitate a rapid neurologic exam post intubation. Consider the contraindications of paralytic agents and use the medication you are most comfortable with as this will likely increase the first pass chance of success. Consider using as first choice rocuronium with sugammadex if available.
Special Population: Pediatric Head Trauma
One of the most common indications for intubation in the emergency department is severe pediatric head injury. It is important to note special considerations when intubating this population. From a trauma standpoint, while pediatric cervical spine injuries are rare, they need to be considered, particularly with severe pediatric head trauma where clinical evaluation of the child is limited. Cervical spine precautions with an assistant holding manual in-line stabilization during airway management should be used in a suspected cervical spine injury or a patient who is otherwise clinically unable to be evaluated.
There is well-documented evidence that each occurrence of hypoxia and hypotension in the pediatric head trauma patient portend a worse outcome. Because of this, steps should be taken to minimize this risk. Adequate preoxygenation, if possible, and minimal apnea time should be used to avoid episodes of hypoxia during intubation.10 In the past, pretreatment with either fentanyl or lidocaine has been recommended to blunt a possible increase in intracranial pressure associated with direct laryngoscopy. The evidence of their effectiveness is limited, but they can be considered as there is little downside.11 For induction medication choice, propofol or a combination of fentanyl and midazolam may not be ideal as these can cause hypotension. Historically, there was a concern using ketamine as it possibly increased intracranial pressure.12 Recent literature has failed to demonstrate this association and the transient hypertension of ketamine may actually increase overall cerebral perfusion pressure. Due to this concern, there is no conclusive recommendation for the pediatric head injury patient. Ketamine is likely safe, however if there is a concern, etomidate can be used.
The Failed Pediatric Airway
In most instances the anxiety of performing a pediatric intubation far outweighs its difficulty. However, there have to be special considerations in children with abnormal airway anatomy from the beginning due to either congenital malformations or trauma or, more concerning, the non-predicted difficult airway. If intubation is unsuccessful most children are easily ventilated with bag-mask ventilation which can be a temporizing measure while more advanced personnel can become available. In patients who are unable to be adequately ventilated with bag mask ventilation, use of a supraglottic device (e.g. laryngeal mask airway) can also be a temporizing measure while attempting to establish a more definitive airway.13,14 It is recommended to have these devices readily available, particularly in a predicted difficult airway such as complex facial trauma or underlying craniofacial abnormalities. In emergent situations the size of the child’s auricle can be a rapid method for sizing a supraglottic device.15
As a final resort surgical airway via needle cricothyrotomy and transtracheal jet ventilation or an emergent surgical cricothyrotomy is a requisite skill for pediatric trauma airway physicians. The exact age at which it is safe to perform an open surgical cricothyrotomy is unclear, however it is not recommended for children under the age of 8 years. It should be noted in a recent review of more than 1200 emergency department intubation attempts in pediatric patients, no surgical airways were performed.3
Summary and Recommendations
Pediatric patients have a different anatomy and physiology as compared to adult patients. Having appropriately sized equipment, as well as minimizing hypoxia and apnea time is critical.
There are several options for both sedation and paralysis, consider ketamine or etomidate depending on the clinical scenario for induction. Both succinylcholine and rocuronium are both options; consideration of the contraindications and comfort level with medications is critical in choosing a paralytic agent.
Hypoxia and hypotension should be aggressively avoided in pediatric head trauma as both are associated with worse outcomes
Have a plan for failed airway including the use of supraglottic device, which should be readily available and part of trauma curriculum and trauma algorithm.
- To rapidly estimate DL blade size of the patient, remember “Miller 2 at 2 and 3 blade at third grade”.
- If you don’t have a length-based resuscitation tape, use this formulate for cuffed ET tube size: (Age/4) + 3.5 = cuffed endotracheal tube size.
- Consider ketamine (2 mg/kg) or etomidate (0.3 mg/kg) as first line for induction of intubation.
- In an emergency situation a supraglottic device can be rapidly sized by comparing it to the auricle of the child.
- Overmann KM, Boyd SD, Zhang Y, Kerrey BT. Apneic oxygenation to prevent oxyhemoglobin desaturation during rapid sequence intubation in a pediatric emergency department. Am J Emerg Med. 2019 Aug;37(8):1416-1421.
- Eisenberg MA, Green-Hopkins I, Werner H, Nagler J. Comparison Between Direct and Video-assisted Laryngoscopy for Intubations in a Pediatric Emergency Department. Acad Emerg Med. 2016 Aug;23(8):870-7.
- Pallin DJ, Dwyer RC, Walls RM, Brown CA. NEAR III Investigators Techniques and Trends, Success Rates, and Adverse Events in Emergency Department Pediatric Intubations: A Report From the National Emergency Airway Registry. Ann Emerg Med. 2016 May;67(5):610-615.
- Shi F et al. Cuffed versus uncuffed endotracheal tubes in children: a meta-analysis. Anesth. 2016 Feb;30(1):3-11.
- Bean A, Jones J. Atropine: re-evaluating its use during paediatric RSI. Emerg Med J. 2007 May;24(5):361-2.
- Zuckerbraun NS, Pitetti RD, Herr SM, Roth KR, Gaines BA, King C. Use of etomidate as an induction agent for rapid sequence intubation in a pediatric emergency department. Acad Emerg Med. 2006 Jun;13(6):602-9.
- Daniel Scherzer, MD, Mark Leder, MD, and Joseph D. Tobias, MD. Pro-Con Debate: Etomidate or Ketamine for Rapid Sequence Intubation in Pediatric Patients. J Pediatr Pharmacol Ther. 2012 Apr;17(2):142-9.
- Mallon WK, Keim SM, Shoenberger JM, Walls RM. Rocuronium vs. succinylcholine in the emergency department: a critical appraisal. J Emerg Med. 2009 Aug;37(2):183-8.
- Herbstritt A, Amarakone K. Towards evidence-based emergency medicine: best BETs from the Manchester Royal Infirmary. BET 3: is rocuronium as effective as succinylcholine at facilitating laryngoscopy during rapid sequence intubation? Emerg Med J. 2012 Mar;29(3):256-8.
- Morrissey K, Fairbrother H. Severe Traumatic Brain Injury In Children: An Evidence-Based Review Of Emergency Department Management. Pediatr Emerg Med Pract. 2016 Oct;13(10):1-28.
- Shein SL, Ferguson NM, Kochanek PM, Bayir H, Clark RS, Fink EL, Tyler-Kabara EC, Wisniewski SR, Tian Y, Balasubramani GK, Bell MJ. Effectiveness of Pharmacological Therapies for Intracranial Hypertension in Children With Severe Traumatic Brain Injury–Results From an Automated Data Collection System Time-Synched to Drug Administration. Pediatr Crit Care Med. 2016 Mar;17(3):236-45.
- Bar-Joseph G, Guilburd Y, Tamir A, Guilburd JN. Effectiveness of ketamine in decreasing intracranial pressure in children with intracranial hypertension. J Neurosurg Pediatr. 2009 Jul;4(1):40-6.
- Hernandez MC, Antiel RM, Balakrishnan K, Zielinski MD, Klinkner DB. Definitive airway management after prehospital supraglottic rescue airway in pediatric trauma. Journal of Pediatric Surgery. 2018;53(2):352-356.
- Jagannathan N, Sequera-Ramos L, Sohn L, Wallis B, Shertzer A, Schaldenbrand K. Elective use of supraglottic airway devices for primary airway management in children with difficult airways. Br J Anaesth. 2014 Apr;112(4):742-8.
- Haliloglu M, Bilgen S, Neslihan U, Koner, O. Simple method for determining the size of the ProSeal laryngeal mask airway in children: a prospective observational study. Brazilian Journal of Anesthesiology. 2017;67(1):15-20.