Supraglottic Airway Devices for Pediatric Airway Management in the Emergency Department

Table of Contents

 

Endotracheal intubation can be difficult in the emergent situation, and having an appropriate backup strategy is important. In many situations, supraglottic airway devices (SGAs) can be used instead of endotracheal intubation to manage a patient’s airway. SGAs provide an alternative method for pediatric airway management that is relatively easy to learn, with a high success rate. This issue reviews indications and techniques for SGA placement, provides evidence-based recommendations for their use, and discusses the use of SGAs in the patient with a difficult airway. You will learn:

Benefits of using SGAs for airway management

Types of SGAs that are commonly used in pediatric patients (including the LMA® Classic™, intubating LMA/LMA® Fastrach™, LMA® ProSeal™, LMA® Supreme™, Combitube®, laryngeal tube airway/King LTS-D™, i-gel®, and Baska Mask®)

Techniques for SGA placement, with a video demonstration of insertion techniques from 4 different angles

Congenital abnormalities and acquired conditions that may predict a difficult airway

Mouth characteristics and scoring techniques (eg, inter-incisor gap, modified Mallampati score, upper-lip bite test, palm print sign, prayer sign) that may predict a difficult airway

Evidence-based recommendations for managing patients with a difficult airway

1. Abstract
2. Case Presentations
3. Introduction
4. Critical Appraisal of the Literature
5. The History of Supraglottic Airway Devices
6. Benefits of Supraglottic Airway Devices
7. Common Supraglottic Airway Devices
   1. LMA® Classic™
   2. Intubating LMA/LMA® Fastrach™
   3. LMA® ProSeal™ and LMA® Supreme™
   4. Combitube®
   5. Laryngeal Tube Airway
   6. i-gel®
   7. Baska Mask®
8. Video: Insertion of Supraglottic Airway Devices
9. The Difficult Airway
   1. Anatomically Difficult Airways
      1. Congenital Abnormalities
      2. Acquired Conditions
   2. Managing the Difficult Airway
10. Prehospital Care
11. Emergency Department Evaluation
    1. History
    2. Physical Examination
       1. Mouth Characteristics
          • Dentition and Palate
          • Inter-incisor Gap
          • Modified Mallampati Score
          • Upper-Lip Bite Test
          • Micrognathia
       2. Thyromental and Hyomental Distances
       3. Cervical Spine
12. Diagnostic Studies
13. Special Circumstances and Challenges
14. Controversies
15. Disposition
16. Summary
17. Risk Management Pitfalls When Using Supraglottic Airway Devices in Pediatric Patients
18. Time- and Cost-Effective Strategies
19. Case Conclusions
20. Tables and Figures
    1. Table 1. Recommended Sizing for the LMA® Classic™ and LMA® ProSeal™, Based on Patient Weight
    2. Table 2. Recommended Sizing for the King LTS-D™, Based on Patient Weight and/or Height
    3. Table 3. Recommended Sizing for the i-gel®, Based on Patient Weight
    4. Table 4. Recommended Sizing for the Baska Mask®, Based on Patient Weight
    5. Table 5. Anatomic Features Associated With Difficult Airways in Children
    6. Figure 1. The LMA® Classic™
    7. Figure 2. The Standard Technique of Placing the LMA® Classic™
    8. Figure 3. LMA® Fastrach™
    9. Figure 4. LMA® ProSeal™
    10. Figure 5. LMA® Supreme™
    11. Figure 6. Combitube®
    12. Figure 7. King LTS-D™
    13. Figure 8. i-gel®
    14. Figure 9. Baska Mask®
    15. Figure 10. Modified Mallampati Score
    16. Figure 11. Upper-Lip Bite Test
    17. Figure 12. Positive Palm Print Sign and Prayer Sign
21. References

Abstract

Endotracheal intubation can be difficult in the emergent situation, and it is important to have an appropriate backup strategy. Supraglottic airway devices have provided an alternative method for pediatric airway management that is relatively easy to learn, with a high success rate. This issue reviews the use of supraglottic airway devices in pediatric patients including common devices, indications and techniques for placement, and complications associated with their use. The use of supraglottic airway devices in the patient with a difficult airway is also discussed.

Case Presentations

You are working in the ED when EMS arrives with a 4-year-old boy who is in respiratory distress. The paramedics report that the boy was seen earlier at an urgent care center and was diagnosed with influenza A by point-of-care testing. On examination, you note a visibly smaller mandible and a tongue set farther back than its typical position. His mother confirms that the boy has Pierre Robin sequence. As the patient is placed on a stretcher, you note that he is tired appearing, with significant nasal congestion and micrognathia. His vital signs are notable for a fever of 39.6°C (103.3°F), respiratory rate of 14 breaths/min, and oxygen saturation of 88% on room air. You are concerned about securing his airway, given his facial anomalies. What equipment should be kept at the bedside in case this progresses to respiratory failure? Is there a backup airway device that should be readily available? Should an advanced airway team be called?

During your next shift in the ED, you are caring for a 15-year-old boy with a traumatic elbow dislocation that occurred while he was playing soccer. The orthopedic surgeon on call would like to reduce the dislocation in the ED using procedural sedation. The patient recovered from an upper respiratory tract infection a couple of days ago, and you are concerned about possible airway complications. Does the recent upper respiratory tract infection increase the risk for possible airway compromise? Should this procedure be attempted without sedation?

While you are signing your note from the previous case, another patient arrives in the ED. It is a 5-month-old girl who is brought in by her mother after an episode of cyanosis at home. The girl has a history of congenital heart disease and a Blalock–Taussig shunt. Although the infant’s initial vital signs are initially reassuring, she quickly becomes limp and pale. On re-evaluation you note a heart rate in the 50s, with poor peripheral perfusion. Your team initiates cardiopulmonary resuscitation, and you prepare to secure her airway. You have limited experience with infants this age and must decide between endotracheal intubation or use of a supraglottic airway device. In a patient this age, would placing a supraglottic airway device be easier or could insertion be more complicated than in an older child?

Introduction

Supraglottic airways are a group of airway devices used to secure a patient’s airway or as an aid to facilitate endotracheal intubation (ETI). The term supraglottic indicates that these devices sit just above the larynx and allow for oxygenation and ventilation. These devices are sometimes referred to as “extraglottic” instead of “supraglottic.” For the purposes of this article, these devices will be referred to as supraglottic airway devices (SGAs).

Airway management in the ED can be indicated for respiratory arrest or failure, inability to maintain the airway due to altered level of consciousness, or for procedures and diagnostic studies. ETI can be difficult in the emergent situation, and having an appropriate backup strategy is important. In many situations, SGAs can be used instead of ETI to manage a patient’s airway. Since oxygenation and ventilation can be provided through an SGA without the need for ETI, these devices provide a quick and safe method for managing difficult airways in pediatric patients in the ED.

SGAs are useful in the management of the difficult airway. They have been used in this capacity in the operating room, prehospital setting, and emergency department setting. Guidelines for management of a difficult airway in both adult and pediatric patients now commonly incorporate the use of SGAs into their suggested recommended workflow.^1-3 In 1991, Benumof described the usefulness of SGAs in the “can’t intubate, can’t ventilate” scenario.⁴ Use of these devices to restore and maintain ventilation and oxygenation in adults, children, and infants with difficult airways has been published for many years.^5-11 One study described a 94% success rate in providing rescue ventilation with SGAs in adults with unexpected difficult intubation and difficult bag-valve mask ventilation.¹² A variety of SGAs are available to aid in performance of a difficult tracheal intubation. In several studies, fiberoptic intubation was significantly more successful on first attempt when using an intubating laryngeal mask airway (LMA).^13,14 One example is the air-Q® intubating laryngeal airway used as a conduit for intubation in the pediatric patient with a difficult airway.^15,16

This issue of Pediatric Emergency Medicine Practice reviews the history of SGAs, discusses types of devices that are commonly used in pediatric patients, and provides evidence-based recommendations for their use.

Critical Appraisal of the Literature

A literature search was performed in PubMed using the following search terms (and their combinations): pediatrics, children, anesthesia, pre-hospital, supraglottic, extraglottic, airway, emergency, intubation, laryngeal mask airway, LMA, combitube, iGel, SLIPA, Streamlined Liner of the Pharynx Airway, King Airway, and baska. Additionally, the bibliographies of articles were reviewed for other relevant publications. A search of the Cochrane Database of Systematic Reviews using the term supraglottic yielded 3 published articles. The first article compared SGAs and ETI in obese patients undergoing general anesthesia.¹⁷ The second compared 2 types of devices (LMA^® Classic^TM [cLMA] and ProSeal™) for positive pressure ventilation in adults undergoing elective surgery.¹⁸ The third compared tracheal intubation with a flexible scope and other intubation techniques in obese patients undergoing general anesthesia.¹⁹ A total of 382 articles were reviewed, and 137 were chosen for inclusion. The evidence is backed by several high-quality studies, 7 practice guidelines, 16 randomized controlled trials, and 17 meta-analyses/systematic reviews. Due to a general paucity of pediatric literature on SGAs, much of the review led to adult-based scientific publications; many were included and applied to the pediatric population.

The History of Supraglottic Airway Devices

The pharyngeal bulb gasway was the first SGA. It was developed in the late 1930s by Beverley Charles Leech, who designed a device that would conform to the average adult pharynx, forming an airtight seal and allowing for the passage of gases through its core.²⁰ This product fell out of favor with advancements in ETI.

Archie Brain introduced the next SGA in 1983. He noted that better gas exchange could be accomplished with an end-to-end connection at the perimeter of the larynx instead of the tube-in-a-tube method used with an endotracheal tube (ETT). This was accomplished via an elliptical cuff at the distal end of the SGA, which creates an airtight seal at the perimeter of the larynx when inflated.^21,22 Initially available only in the United Kingdom, it quickly began being used in the United States, Australia, and Japan. The laryngeal mask was originally limited for use in patients who were under anesthesia but breathing spontaneously. Since then, the use of these devices has expanded to include use with controlled ventilation during operative procedures and as rescue devices.^23,24 The LMA is produced by LMA^® North America, Inc, and the term laryngeal mask is used generally for products made by any other manufacturer.²⁵

The LMA was first approved by the United States Food and Drug Administration in 1991, and it has been adopted as one of the standard methods for providing oxygenation and ventilation in the operating room.²⁶ Increased use has led to the development of a newer, “second generation” of SGAs. Pediatric anesthesiologists use SGAs in various situations, and they have adopted SGAs as a primary airway in children with difficult airways who are undergoing elective procedures.²⁷ The use of SGAs during head and neck procedures is quite frequent; a survey by Patel and colleagues found that many pediatric anesthesiologists were comfortable using an SGA in situations that are considered more complicated, including laparoscopic surgery and in patients placed in the prone position.²⁸ Although there is a theoretical risk that the SGA could be more easily dislodged while lying the patient prone, the literature supports use in this position.^29,30

It has been noted that the smaller pediatric LMAs (sizes 1-2.5) can be more likely to partially block the glottic opening than larger models, due to malpositioning.³¹ When using smaller sizes, remember that these SGAs may require more frequent repositioning.

SGAs are often used in adult patients in cardiac arrest. SGAs can be placed quickly without interruption of cardiopulmonary resuscitation efforts, and they have been shown to provide similar oxygenation and ventilation in these situations when compared to ETI.^32,33 The ability to intubate through some models also makes them an important component of any backup airway situation.

Video: Insertion of Supraglottic Airway Devices

To view a video featuring Dr. Rich Levitan of Continulus.com reviewing types of SGAs and demonstrating insertion techniques from 4 different angles, see the video below:

For the complete Emergency Airway Masterclass with Rich Levitan from Continulus, go to Command the Airway with Rich Levitan. EB Medicine subscribers get 15% off! Use promo code EBM-15.

Risk Management Pitfalls When Using Supraglottic Airway Devices in Pediatric Patients

1. “The child did not have difficult airway features, so I did not have a backup airway ready.”

One study found that 20% of difficult airways in children were unanticipated.89 This contrasts the belief that pediatric difficult airway cases should be predictable. Clinicians should prepare to manage a difficult airway, regardless of the lack history or physical examination indicators.

2. “I did not know the child’s weight, so I chose the SGA size equivalent to the blade size.”

SGA sizing does not correlate with blade size or ETT size. When a patient’s weight is not known, a suitable LMA size can be determined using the combined width of the patient’s second, third, and fourth digits.46 The Broselow-Luten resuscitation tape, if available, contains LMA sizing and can be used to choose the correct LMA based on the patient’s height. There are other weight estimation formulas that do not require Broselow-Luten tape.

10. “The patient arrived with an SGA in place, so I removed it to place an ETT.”

Although SGAs have a greater risk of dislodgement than an ETT, it would not be prudent to remove a working advanced airway in an emergent situation. If the SGA has intubating capacity, an ETT may be placed somewhat easily. Alternatively, if the SGA is large enough to pass a bougie, it is possible to change it to an ETT using a Seldinger-like technique. Regardless, if physiologic parameters (pulse oximetry, waveform capnography) are within an acceptable range with an SGA in place, the patient should be stabilized prior to removing or replacing the SGA.

Tables and Figures

References

Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.

To help the reader judge the strength of each reference, pertinent information about the study, such as the type of study and the number of patients in the study is included in bold type following the references, where available. The most informative references cited in this paper, as determined by the authors, are noted by an asterisk (*) next to the number of the reference.

1. Black AE, Flynn PE, Smith HL, et al. Development of a guideline for the management of the unanticipated difficult airway in pediatric practice. Paediatr Anaesth. 2015;25(4):346-362. (Practice guidelines)
2. Bjurstrom MF, Bodelsson M, Sturesson LW. The difficult airway trolley: a narrative review and practical guide. Anesthesiol Res Pract. 2019;2019:6780254. (Review)
3. Pawar DK, Doctor JR, Raveendra US, et al. All India Difficult Airway Association 2016 guidelines for the management of unanticipated difficult tracheal intubation in paediatrics. Indian J Anaesth. 2016;60(12):906-914. (Practice guidelines) DOI: 10.4103/0019-5049.195483
4. Benumof JL. Management of the difficult adult airway. With special emphasis on awake tracheal intubation. Anesthesiology. 1991;75(6):1087-1110. (Review)
5. Fundingsland BW, Benumof JL. Difficulty using a laryngeal mask airway in a patient with lingual tonsil hyperplasia. Anesthesiology. 1996;84(5):1265-1266. (Correspondence)
6. Kidani DC, Shah NK. The use of a laryngeal mask airway after a prolonged suspension laryngoscopy to preserve a vocal cord fat graft. Anesth Analg. 2007;105(6):1753-1754. (Case report)
7. Augoustides JG, Groff BE, Mann DG, et al. Difficult airway management after carotid endarterectomy: utility and limitations of the laryngeal mask airway. J Clin Anesth. 2007;19(3):218-221. (Case series; 2 patients)
8. Leal-Pavey YR. Use of the LMA classic to secure the airway of a premature neonate with Smith-Lemli-Opitz syndrome: a case report. AANA J. 2004;72(6):427-430. (Case report)
9. Rowbottom SJ, Simpson DL, Grubb D. The laryngeal mask airway in children. A fibreoptic assessment of positioning. Anaesthesia. 1991;46(6):489-491. (Prospective; 100 patients)
10. Brimacombe J. The advantages of the LMA over the tracheal tube or facemask: a meta-analysis. Can J Anaesth. 1995;42(11):1017-1023. (Meta-analysis; 52 studies) DOI: 10.1007/bf03011075
11. Mizushima A, Wardall GJ, Simpson DL. The laryngeal mask airway in infants. Anaesthesia. 1992;47(10):849-851. (Prospective; 50 patients)
12. Parmet JL, Colonna-Romano P, Horrow JC, et al. The laryngeal mask airway reliably provides rescue ventilation in cases of unanticipated difficult tracheal intubation along with difficult mask ventilation. Anesth Analg. 1998;87(3):661-665. (Retrospective; 25 patients)
13. Asai T, Eguchi Y, Murao K, et al. Intubating laryngeal mask for fibreoptic intubation--particularly useful during neck stabilization. Can J Anaesth. 2000;47(9):843-848. (Prospective; 124 patients)
14. Bhatnagar S, Mishra S, Jha RR, et al. The LMA Fastrach facilitates fibreoptic intubation in oral cancer patients. Can J Anaesth. 2005;52(6):641-645. (Prospective; 40 patients)
15. Jagannathan N, Kho MF, Kozlowski RJ, et al. Retrospective audit of the air-Q intubating laryngeal airway as a conduit for tracheal intubation in pediatric patients with a difficult airway. Paediatr Anaesth. 2011;21(4):422-427. (Retrospective; 34 patients)
16. Sinha R, Chandralekha, Ray BR. Evaluation of air-Q intubating laryngeal airway as a conduit for tracheal intubation in infants--a pilot study. Paediatr Anaesth. 2012;22(2):156-160. (Prospective; 20 patients)
17. Nicholson A, Cook TM, Smith AF, et al. Supraglottic airway devices versus tracheal intubation for airway management during general anaesthesia in obese patients. Cochrane Database Syst Rev. 2013(9): CD010105. (Systematic review; 2 studies, 232 participants) DOI: 10.1002/14651858.CD010105.pub2
18. Qamarul Hoda M, Samad K, Ullah H. ProSeal versus Classic laryngeal mask airway (LMA) for positive pressure ventilation in adults undergoing elective surgery. Cochrane Database Syst Rev. 2017(7):CD009026. (Systematic review; 8 studies, 829 participants) DOI: 10.1002/14651858.CD009026.pub2
19. Nicholson A, Smith AF, Lewis SR, et al. Tracheal intubation with a flexible intubation scope versus other intubation techniques for obese patients requiring general anaesthesia. Cochrane Database Syst Rev. 2014(1):CD010320. (Systematic review; 3 studies, 131 participants) DOI: 10.1002/14651858.CD010320.pub2
20. Leech BC. The pharyngeal bulb gasway: a new aid in cyclopropane anesthesia. Anesth Analg. 1937;16(1):22-25. (Review)
21. Brain AI. The laryngeal mask--a new concept in airway management. Br J Anaesth. 1983;55(8):801-805. (Pilot study; 23 patients)
22. Brain AI. The development of the laryngeal mask--a brief history of the invention, early clinical studies and experimental work from which the laryngeal mask evolved. Eur J Anaesthesiol Suppl. 1991;4:5-17. (Review)
23. Hernandez MR, Klock PA Jr, Ovassapian A. Evolution of the extraglottic airway: a review of its history, applications, and practical tips for success. Anesth Analg. 2012;114(2):349-368. (Review)
24. Ostermayer DG, Gausche-Hill M. Supraglottic airways: the history and current state of prehospital airway adjuncts. Prehosp Emerg Care. 2014;18(1):106-115. (Review)
25. Benumof J, Hagberg CA. Benumof and Hagberg’s Airway Management. Philadelphia: Elsevier/Saunders; 2012. (Book)
26. Pinosky M. Laryngeal mask airway: uses in anesthesiology. South Med J. 1996;89(6):551-555. (Review)
27. Jagannathan N, Sequera-Ramos L, Sohn L, et al. Elective use of supraglottic airway devices for primary airway management in children with difficult airways. Br J Anaesth. 2014;112(4):742-748. (Retrospective; 109 patients)
28. Patel A, Clark SR, Schiffmiller M, et al. A survey of practice patterns in the use of laryngeal mask by pediatric anesthesiologists. Paediatr Anaesth. 2015;25(11):1127-1131. (Survey; 743 responses)
29. Lopez AM, Valero R, Hurtado P, et al. Comparison of the LMA Supreme with the LMA Proseal for airway management in patients anaesthetized in prone position. Br J Anaesth. 2011;107(2):265-271. (Randomized controlled trial; 120 patients)
30. Sinha A, Sharma B, Sood J. ProSeal as an alternative to endotracheal intubation in pediatric laparoscopy. Paediatr Anaesth. 2007;17(4):327-332. (Randomized controlled trial; 60 patients)
31. Von Ungern-Sternberg BS, Wallace CJ, Sticks S, et al. Fibreoptic assessment of paediatric sized laryngeal mask airways. Anaesth Intensive Care. 2010;38(1):50-54. (Prospective; 350 patients)
32. Wang HE, Schmicker RH, Daya MR, et al. Effect of a strategy of initial laryngeal tube insertion vs endotracheal intubation on 72-hour survival in adults with out-of-hospital cardiac arrest: a randomized clinical trial. JAMA. 2018;320(8):769-778. (Prospective; 3004 patients)
33. Benger JR, Kirby K, Black S, et al. Effect of a strategy of a supraglottic airway device vs tracheal intubation during out-of-hospital cardiac arrest on functional outcome: the AIRWAYS-2 randomized clinical trial. JAMA. 2018;320(8):779-791. (Randomized controlled trial; 9296 patients)
34. Lopez-Gil M, Brimacombe J, Alvarez M. Safety and efficacy of the laryngeal mask airway. A prospective survey of 1400 children. Anaesthesia. 1996;51(10):969-972. (Prospective; 1400 patients) DOI: 10.1111/j.1365-2044.1996.tb14968.x
35. Jannu A, Shekar A, Balakrishna R, et al. Advantages, disadvantages, indications, contraindications and surgical technique of laryngeal airway mask. Arch Craniofac Surg. 2017;18(4):223-229. (Review)
36. Pennant JH, Pace NA, Gajraj NM. Role of the laryngeal mask airway in the immobile cervical spine. J Clin Anesth. 1993;5(3):226-230. (Randomized controlled trial; 28 patients)
37. Tait AR, Malviya S, Voepel-Lewis T, et al. Risk factors for perioperative adverse respiratory events in children with upper respiratory tract infections. Anesthesiology. 2001;95(2):299-306. (Prospective; 1078 patients)
38. Luce V, Harkouk H, Brasher C, et al. Supraglottic airway devices vs tracheal intubation in children: a quantitative meta-analysis of respiratory complications. Paediatr Anaesth. 2014;24(10):1088-1098. (Meta-analysis; 19 studies) DOI: 10.1111/pan.12495
39. von Ungern-Sternberg BS, Boda K, Chambers NA, et al. Risk assessment for respiratory complications in paediatric anaesthesia: a prospective cohort study. Lancet. 2010;376(9743):773-783. (Questionnaire; 9297 responses)
40. Wilson IG, Fell D, Robinson SL, et al. Cardiovascular responses to insertion of the laryngeal mask. Anaesthesia. 1992;47(4):300-302. (Prospective; 40 patients)
41. Braude N, Clements EA, Hodges UM, et al. The pressor response and laryngeal mask insertion. A comparison with tracheal intubation. Anaesthesia. 1989;44(7):551-554. (Prospective; 47 patients)
42. Agrawal G, Agarwal M, Taneja S. A randomized comparative study of intraocular pressure and hemodynamic changes on insertion of proseal laryngeal mask airway and conventional tracheal intubation in pediatric patients. J Anaesthesiol Clin Pharmacol. 2012;28(3):326-329. (Prospective; 59 patients)
43. Bhardwaj N, Yaddanapudi S, Singh S, et al. Insertion of laryngeal mask airway does not increase the intraocular pressure in children with glaucoma. Paediatr Anaesth. 2011;21(10):1036-1040. (Randomized controlled trial; 30 patients)
44. Hashmi NK, McCartney S, Jones LH, et al. 49 - Emergency airway management. In: Brown DL, ed. Cardiac Intensive Care 3rd ed. Philadelphia: Elsevier; 2019:525-547. (Book chapter)
45. Kagawa T, Obara H. An easy formula to remember the laryngeal mask airway size-patient weight relationship. Anesthesiology. 2000;92(2):631-632. (Letter to the editor)
46. Gallart L, Mases A, Martinez J, et al. Simple method to determine the size of the laryngeal mask airway in children. Eur J Anaesthesiol. 2003;20(7):570-574. (Clinical trial; 142 patients)
47. Teleflex. LMA® Classic™. The classic laryngeal mask. Accessed September 15, 2020. (Product information)
48. Teleflex. LMA® ProSeal™. Proven versatility. Accessed September 15, 2020. (Product information)
49. Chen L, Hsiao AL. Randomized trial of endotracheal tube versus laryngeal mask airway in simulated prehospital pediatric arrest. Pediatrics. 2008;122(2):e294-e297. (Randomized cross-over study; 52 participants)
50. Simon LV, Torp KD. Laryngeal mask airway. StatPearls. Treasure Island: StatPearls Publishing; 2020. (Review)
51. Soh CR, Ng AS. Laryngeal mask airway insertion in paediatric anaesthesia: comparison between the reverse and standard techniques. Anaesth Intensive Care. 2001;29(5):515-519. (Randomized clinical trial; 67 patients)
52. Roodneshin F, Agah M. Novel technique for placement of laryngeal mask airway in difficult pediatric airways. Tanaffos. 2011;10(2):56-68. (Clinical trial; 30 patients)
53. Baskett PJ, Parr MJ, Nolan JP. The intubating laryngeal mask. Results of a multicentre trial with experience of 500 cases. Anaesthesia. 1998;53(12):1174-1179. (Prospective; 500 patients)
54. Ferson DZ, Rosenblatt WH, Johansen MJ, et al. Use of the intubating LMA-Fastrach in 254 patients with difficult-to-manage airways. Anesthesiology. 2001;95(5):1175-1181. (Prospective; 254 patients)
55. Shah VR, Bhosale GP, Mehta T, et al. A comparison of conventional endotracheal tube with silicone wire-reinforced tracheal tube for intubation through intubating laryngeal mask airway. Saudi J Anaesth. 2014;8(2):183-187. (Prospective; 60 patients)
56. Kundra P, Sujata N, Ravishankar M. Conventional tracheal tubes for intubation through the intubating laryngeal mask airway. Anesth Analg. 2005;100(1):284-288. (Randomized controlled trial; 150 patients)
57. Teleflex. LMA® Fastrach™. Accessed September 15, 2020. (Product information)
58. Keller C, Brimacombe J, Kleinsasser A, et al. Does the ProSeal laryngeal mask airway prevent aspiration of regurgitated fluid? Anesth Analg. 2000;91(4):1017-1020. (Randomized cross-over cadaver study; 10 cadavers)
59. Cook TM, Gibbison B. Analysis of 1000 consecutive uses of the ProSeal laryngeal mask airway by one anaesthetist at a district general hospital. Br J Anaesth. 2007;99(3):436-439. (Prospective consecutive series; 1000 patients)
60. Drolet P, Girard M. An aid to correct positioning of the ProSeal laryngeal mask. Can J Anaesth. 2001;48(7):718-719. (Letter to the editor)
61. Wong DT, Yang JJ, Jagannathan N. Brief review: The LMA Supreme supraglottic airway. Can J Anaesth. 2012;59(5):483-493. (Review)
62. Hilton MT, Wayne M, Martin-Gill C. Impact of system-wide King LT airway implementation on orotracheal intubation. Prehosp Emerg Care. 2016;20(5):570-577. (Retrospective; 712 cases)
63. QuadMed. Combitube®. Accessed September 15, 2020. (Product information)
64. Centers for Disease Control and Prevention. Growth charts boys. Accessed September 15, 2020. (Growth chart)
65. Centers for Disease Control and Prevention. Growth charts girls. Accessed September, 15, 2020. (Growth chart)
66. Ambu. King LTS-D™. Accessed September 15, 2020. (Product information)
67. Intersurgical. i-gel® supraglottic airway. Accessed September 15, 2020. (Product information)
68. Sharda M, Kapoor MC, Atray R, et al. Insertion of i-gel™ by the reversed technique improves the success rate and reduces the time taken for its placement: a prospective, randomized, controlled, interventional trial. J Anaesthesiol Clin Pharmacol. 2017;33(2):226-230. (Randomized controlled trial; 100 patients)
69. Bielski A, Smereka J, Madziala M, et al. Comparison of blind intubation with different supraglottic airway devices by inexperienced physicians in several airway scenarios: a manikin study. Eur J Pediatr. 2019;178(6):871-882. (Randomized controlled trial; 116 participants)
70. Smith P, Bailey CR. A performance comparison of the paediatric i-gel with other supraglottic airway devices. Anaesthesia. 2015;70(1):84-92. (Systematic review; 22 studies)
71. Maitra S, Baidya DK, Bhattacharjee S, et al. Evaluation of i-gel(™) airway in children: a meta-analysis. Paediatr Anaesth. 2014;24(10):1072-1079. (Meta-analysis; 9 studies) DOI: 10.1111/pan.12483
72. Schunk D, Ritzka M, Graf B, et al. A comparison of three supraglottic airway devices used by healthcare professionals during paediatric resuscitation simulation. Emerg Med J. 2013;30(9):754-757. (Prospective; 66 participants)
73. Alexiev V, Ochana A, Abdelrahman D, et al. Comparison of the Baska(®) mask with the single-use laryngeal mask airway in low-risk female patients undergoing ambulatory surgery. Anaesthesia. 2013;68(10):1026-1032. (Randomized controlled trial; 150 patients)
74. BVLM. Baska Mask® features. Accessed September 15, 2020. (Product information)
75. BVLM. Baska Mask and Baska FESS mask sizes. Accessed September 15, 2020. (Product information)
76. Kara D, Sarikas CM. Comparison of the Baska and I-gel supraglottic airway devices: a randomized controlled study. Ann Saudi Med. 2019;39(5):302-308. (Randomized controlled trial; 200 patients)
77. Jayalekshmi S, Paul C, Thomas MK. Efficacy of Baska mask and laryngeal mask airway supreme during positive pressure ventilation - a comparative study. J Anaesthesiol Clin Pharmacol. 2020;36(1):31-36. (Prospective; 70 patients)
78. Foo LL, Shariffuddin, II, Chaw SH, et al. Randomized comparison of the Baska FESS mask and the LMA Supreme in different head and neck positions. Expert Rev Med Devices. 2018;15(8):597-603. (Randomized controlled trial; 100 patients)
79. Sachidananda R, Shaikh SI, Mitragotri MV, et al. Comparison between the Baska Mask(®) and i-gel for minor surgical procedures under general anaesthesia. Turk J Anaesthesiol Reanim. 2019;47(1):24-30. (Randomized controlled trial; 50 patients)
80. Zundert T, Gatt S. The Baska Mask® -a new concept in self-sealing membrane cuff extraglottic airway devices, using a sump and two gastric drains: a critical evaluation. J Obstet Anaesth Crit Care. 2012;2(1):23-30. (Prospective; 50 patients) DOI: 10.4103/2249-4472.99313
81. Apfelbaum JL, Hagberg CA, Caplan RA, et al. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013;118(2):251-270. (Practice guidelines) DOI: 10.1097/ALN.0b013e31827773b2
82. Sunder RA, Haile DT, Farrell PT, et al. Pediatric airway management: current practices and future directions. Paediatr Anaesth. 2012;22(10):1008-1015. (Review)
83. Heinrich S, Birkholz T, Ihmsen H, et al. Incidence and predictors of difficult laryngoscopy in 11,219 pediatric anesthesia procedures. Paediatr Anaesth. 2012;22(8):729-736. (Retrospective; 11,219 patients)
84. Heinrich S, Birkholz T, Ihmsen H, et al. Incidence and predictors of poor laryngoscopic view in children undergoing pediatric cardiac surgery. J Cardiothorac Vasc Anesth. 2013;27(3):516-521. (Retrospective; 1177 patients)
85. Mirghassemi A, Soltani AE, Abtahi M. Evaluation of laryngoscopic views and related influencing factors in a pediatric population. Paediatr Anaesth. 2011;21(6):663-667. (Prospective; 511 patients)
86. Raj D, Luginbuehl I. Managing the difficult airway in the syndromic child. Cont Ed Anaesth Crit Care Pain. 2014;15(1):7-13. (Review)
87. Rao MS, Linga Raju Y, Vishwanathan P. Anaesthetic management of difficult airway due to retropharyngeal abscess. Indian J Anaesth. 2010;54(3):246-248. (Case report; 1 patient)
88. Glynn F, Fenton JE. Diagnosis and management of supraglottitis (epiglottitis). Curr Infect Dis Rep. 2008;10(3):200-204. (Review)
89. Karsli C, Pehora C, Al-Izzi A, et al. A retrospective review of pediatric difficult airways: once easy, not always easy. Can J Anaesth. 2016;63(6):776-777. (Retrospective; 22,766 patients)
90. Frova G, Sorbello M. Algorithms for difficult airway management: a review. Minerva Anestesiol. 2009;75(4):201-209. (Review)
91. Timmermann A. Supraglottic airways in difficult airway management: successes, failures, use and misuse. Anaesthesia. 2011;66 Suppl 2:45-56. (Review)
92. Law JA, Broemling N, Cooper RM, et al. The difficult airway with recommendations for management--part 2--the anticipated difficult airway. Can J Anaesth. 2013;60(11):1119-1138. (Practice guidelines)
93. Frerk C, Mitchell VS, McNarry AF, et al. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. Br J Anaesth. 2015;115(6):827-848. (Practice guidelines)
94. Jagannathan N, Sohn L, Fiadjoe JE. Paediatric difficult airway management: what every anaesthetist should know! Br J Anaesth. 2016;117 Suppl 1:i3-i5. (Editorial)
95. Fiadjoe JE, Nishisaki A, Jagannathan N, et al. Airway management complications in children with difficult tracheal intubation from the Pediatric Difficult Intubation (PeDI) Registry: a prospective cohort analysis. Lancet Respir Med. 2016;4(1):37-48. (Prospective; 1018 patients)
96. Weiss M, Engelhardt T. Proposal for the management of the unexpected difficult pediatric airway. Paediatr Anaesth. 2010;20(5):454-464. (Review)
97. Henderson JJ, Popat MT, Latto IP, et al. Difficult Airway Society guidelines for management of the unanticipated difficult intubation. Anaesthesia. 2004;59(7):675-694. (Practice guidelines) DOI: 10.1111/j.1365-2044.2004.03831.x
98. Difficult Airway Society Extubation Guidelines Group, Popat M, Mitchell V, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. Anaesthesia. 2012;67(3):318-340. (Practice guidelines)
99. Klucka J, Stourac P, Stoudek R, et al. Controversies in pediatric perioperative airways. Biomed Res Int. 2015;2015:368761. (Review)
100. Jimenez N, Posner KL, Cheney FW, et al. An update on pediatric anesthesia liability: a closed claims analysis. Anesth Analg. 2007;104(1):147-153. (Retrospective; 532 patients)
101. Mamie C, Habre W, Delhumeau C, et al. Incidence and risk factors of perioperative respiratory adverse events in children undergoing elective surgery. Paediatr Anaesth. 2004;14(3):218-224. (Prospective; 800 patients)
102. Murat I, Constant I, Maud’huy H. Perioperative anaesthetic morbidity in children: a database of 24,165 anaesthetics over a 30-month period. Paediatr Anaesth. 2004;14(2):158-166. (Prospective; 1829 patients)
103. Calder I, Yentis SM. Could ‘safe practice’ be compromising safe practice? Should anaesthetists have to demonstrate that face mask ventilation is possible before giving a neuromuscular blocker? Anaesthesia. 2008;63(2):113-115. (Editorial comment)
104. Larson CP Jr. Laryngospasm--the best treatment. Anesthesiology. 1998;89(5):1293-1294. (Correspondence)
105. Huang AS, Hajduk J, Jagannathan N. Advances in supraglottic airway devices for the management of difficult airways in children. Expert Rev Med Devices. 2016;13(2):157-169. (Review)
106. Miller KA, Nagler J. Advances in emergent airway management in pediatrics. Emerg Med Clin North Am. 2019;37(3):473-491. (Review)
107. Karsli C. Managing the challenging pediatric airway: continuing professional development. Can J Anaesth. 2015;62(9):1000-1016. (Review)
108. Mittal M. Needle cricothyroidotomy with percutaneous transtracheal ventilation. UpToDate. Published 2020. Accessed September 15, 2020. (Review)
109. Braude D, Richards M. Rapid sequence airway (RSA)--a novel approach to prehospital airway management. Prehosp Emerg Care. 2007;11(2):250-252. (Review)
110. Hubble MW, Wilfong DA, Brown LH, et al. A meta-analysis of prehospital airway control techniques part II: alternative airway devices and cricothyrotomy success rates. Prehosp Emerg Care. 2010;14(4):515-530. (Meta-analysis; 35 studies) DOI: 10.3109/10903127.2010.497903
111. Guyette FX, Roth KR, LaCovey DC, et al. Feasibility of laryngeal mask airway use by prehospital personnel in simulated pediatric respiratory arrest. Prehosp Emerg Care. 2007;11(2):245-249. (Prospective; 13 participants)
112. Reinhart DJ, Simmons G. Comparison of placement of the laryngeal mask airway with endotracheal tube by paramedics and respiratory therapists. Ann Emerg Med. 1994;24(2):260-263. (Prospective; 19 participants)
113. Gandini D, Brimacombe J. Manikin training for neonatal resuscitation with the laryngeal mask airway. Paediatr Anaesth. 2004;14(6):493-494. (Prospective; 80 participants)
114. Donoghue AJ, Nadkarni V, Berg RA, et al. Out-of-hospital pediatric cardiac arrest: an epidemiologic review and assessment of current knowledge. Ann Emerg Med. 2005;46(6):512-522. (Systematic review; 41 studies)
115. Sirbaugh PE, Pepe PE, Shook JE, et al. A prospective, population-based study of the demographics, epidemiology, management, and outcome of out-of-hospital pediatric cardiopulmonary arrest. Ann Emerg Med. 1999;33(2):174-184. (Prospective; 300 patients)
116. Wang CY, Wang JY, Teng NC, et al. The secular trends in the incidence rate and outcomes of out-of-hospital cardiac arrest in Taiwan--a nationwide population-based study. PLoS One. 2015;10(4):e0122675. (Retrospective; 117,787 patients)
117. Park CB, Shin SD, Suh GJ, et al. Pediatric out-of-hospital cardiac arrest in Korea: a nationwide population-based study. Resuscitation. 2010;81(5):512-517. (Retrospective; 971 patients)
118. Okubo M, Komukai S, Izawa J, et al. Prehospital advanced airway management for paediatric patients with out-of-hospital cardiac arrest: a nationwide cohort study. Resuscitation. 2019;145:175-184. (Cohort study; 3801 patients) DOI: 10.1016/j.resuscitation.2019.09.007
119. Tweed J, George T, Greenwell C, et al. Prehospital airway management examined at two pediatric emergency centers. Prehosp Disaster Med. 2018;33(5):532-538. (Retrospective; 104 patients)
120. Hansen ML, Lin A, Eriksson C, et al. A comparison of pediatric airway management techniques during out-of-hospital cardiac arrest using the CARES database. Resuscitation. 2017;120:51-56. (Retrospective; 3793 patients)
121. Barr SS, G; Darroch, S. Use of supraglottic airway devices by paramedics in the management of adult prehospital cardiac arrest patients. Australian J Paramedicine. 2017;14(1). (Systematic review; 22 articles)
122. Benoit JL, Gerecht RB, Steuerwald MT, et al. Endotracheal intubation versus supraglottic airway placement in out-of-hospital cardiac arrest: a meta-analysis. Resuscitation. 2015;93:20-26. (Meta-analysis; 10 studies) DOI: 10.1016/j.resuscitation.2015.05.007
123. Hasegawa K, Hiraide A, Chang Y, et al. Association of prehospital advanced airway management with neurologic outcome and survival in patients with out-of-hospital cardiac arrest. JAMA. 2013;309(3):257-266. (Prospective; 649,654 patients)
124. Fouche PF, Simpson PM, Bendall J, et al. Airways in out-of-hospital cardiac arrest: systematic review and meta-analysis. Prehosp Emerg Care. 2014;18(2):244-256. (Meta-analysis; 17 studies, 388,878 patients)
125. Crawley S, Dalton A. Predicting the difficult airway. BJA Education. 2014;15(5):253-257. (Review)
126. Ayuso MA, Sala X, Luis M, et al. Predicting difficult orotracheal intubation in pharyngo-laryngeal disease: preliminary results of a composite index. Can J Anaesth. 2003;50(1):81-85. (Prospective; 181 patients)
127. Bala R, Hazarika A, Pandia MP, et al. High arch palate: a bane for ProSeal laryngeal mask airway but a boon for i-gel. J Anaesthesiol Clin Pharmacol. 2015;31(4):568. (Letter to the editor)
128. Detsky ME, Jivraj N, Adhikari NK, et al. Will this patient be difficult to intubate?: The Rational Clinical Examination Systematic Review. JAMA. 2019;321(5):493-503. (Meta-analysis; 62 studies, 33,559 patients) DOI: 10.1001/jama.2018.21413
129. Shiga T, Wajima Z, Inoue T, et al. Predicting difficult intubation in apparently normal patients: a meta-analysis of bedside screening test performance. Anesthesiology. 2005;103(2):429-437. (Systematic review; 35 studies)
130. Amadasun FE, Adudu OP, Sadiq A. Effects of position and phonation on oropharyngeal view and correlation with laryngoscpic view. Niger J Clin Pract. 2010;13(4):417-420. (Prospective; 400 patients)
131. Awasthi P, Gautam S, Malik A, et al. Comparison of Mallampati test in supine and upright positions with and without phonation in predicting difficult laryngoscopy and intubation in age groups 3-10 years. Ped Anes and Crit Care J. 2018;6(2):61-67. (Prospective; 100 patients)
132. Santos AP, Mathias LA, Gozzani JL, et al. Difficult intubation in children: applicability of the Mallampati index. Rev Bras Anestesiol. 2011;61(2):156-158, 159-162, 184-157. (Prospective; 108 patients)
133. Lee A, Fan LT, Gin T, et al. A systematic review (meta-analysis) of the accuracy of the Mallampati tests to predict the difficult airway. Anesth Analg. 2006;102(6):1867-1878. (Systematic review; 42 studies)
134. Khan ZH, Kashfi A, Ebrahimkhani E. A comparison of the upper lip bite test (a simple new technique) with modified Mallampati classification in predicting difficulty in endotracheal intubation: a prospective blinded study. Anesth Analg. 2003;96(2):595-599. (Prospective; 300 patients)
135. Badheka JP, Doshi PM, Vyas AM, et al. Comparison of upper lip bite test and ratio of height to thyromental distance with other airway assessment tests for predicting difficult endotracheal intubation. Indian J Crit Care Med. 2016;20(1):3-8. (Prospective; 170 patients)
136. el-Ganzouri AR, McCarthy RJ, Tuman KJ, et al. Preoperative airway assessment: predictive value of a multivariate risk index. Anesth Analg. 1996;82(6):1197-1204. (Comparative study; 10,507 patients)
137. Huh J, Shin HY, Kim SH, et al. Diagnostic predictor of difficult laryngoscopy: the hyomental distance ratio. Anesth Analg. 2009;108(2):544-548. (Prospective; 213 patients)
138. Tripathi M, Pandey M. Short thyromental distance: a predictor of difficult intubation or an indicator for small blade selection? Anesthesiology. 2006;104(6):1131-1136. (Randomized controlled trial; 11 patients)
139. Savva D. Prediction of difficult tracheal intubation. Br J Anaesth. 1994;73(2):149-153. (Prospective; 350 patients)
140. Erden V, Basaranoglu G, Delatioglu H, et al. Relationship of difficult laryngoscopy to long-term non-insulin-dependent diabetes and hand abnormality detected using the ‘prayer sign’. Br J Anaesth. 2003;91(1):159-160. (Prospective; 80 patients)
141. Nadal JL, Fernandez BG, Escobar IC, et al. The palm print as a sensitive predictor of difficult laryngoscopy in diabetics. Acta Anaesthesiol Scand. 1998;42(2):199-203. (Prospective; 83 patients)
142. Dargin J, Medzon R. Emergency department management of the airway in obese adults. Ann Emerg Med. 2010;56(2):95-104. (Review)
143. Murphy C, Wong DT. Airway management and oxygenation in obese patients. Can J Anaesth. 2013;60(9):929-945. (Review)
144. Nicholson A, Cook TM, Smith AF, et al. Supraglottic airway devices versus tracheal intubation for airway management during general anaesthesia in obese patients. Cochrane Database Syst Rev. 2013(9):CD010105. (Meta-analysis; 2 studies, 232 participants)
145. Prabha R, Raman R, Khan MP, et al. Comparison of i-gel for general anesthesia in obese and nonobese patients. Saudi J Anaesth. 2018;12(4):535-539. (Prospective; 16 patients)
146. Lavonas EJ, Ohshimo S, Nation K, et al. Advanced airway interventions for paediatric cardiac arrest: a systematic review and meta-analysis. Resuscitation. 2019;138:114-128. (Meta-analysis; 14 studies)
147. Thomassen O, Storesund A, Softeland E, et al. The effects of safety checklists in medicine: a systematic review. Acta Anaesthesiol Scand. 2014;58(1):5-18. (Systematic review; 29 studies)