Javascript is currently disabled in your browser. When javascript is disabled, some functions of this website will not work.
Open access for scientific and medical research
From submission to the first editing decision.
From editor acceptance to publication.
Open access to peer-reviewed scientific and medical journals.
Dove Medical Press is a member of OAI.
Batch reprints for the pharmaceutical industry.
We provide real benefits for authors, including fast processing of papers.
Register your specific details and specific drugs of interest, and we will match the information you provide with articles in our extensive database and send you a PDF copy via email in a timely manner.
Back to Journal »Medical Devices: Evidence and Research» Volume 14
Features of a new type of laryngeal mask airway intubation device on flexible endoscope
Authors: Vivian VH, Pardon TL, Vivian S, Van Zundert A
Published on July 6, 2021, Volume 2021: 14 pages, pages 217-223
DOI https://doi.org/10.2147/MDER.S310415
Single anonymous peer review
Editor approved for publication: Dr. Scott Fraser
Vernon H Vivian,1 Tyson L Pardon,2 Samuel Vivian,3 André Van Zundert4,5 1Department of Anesthesiology, Sunshine Coast Gympie General Hospital, Sunshine Coast, Queensland, Australia; 2Sunshine Coast, Sunshine Cost Health Services Emergency Department, Sunshine Coast, Queensland, Australia; 3 Pre-hospital EMS, Queensland Ambulance Service, Brisbane, Queensland, Australia; 4Department of Anesthesiology, Royal Brisbane Women's Hospital, Brisbane, Australia; 5University of Queensland, Brisbane, Queensland, Australia Corresponding Author: Vernon H Vivian Email [Email Protected] Abstract: Laryngeal mask airway (LMA) is widely used for airway management in hospitals and in-hospital emergency and elective treatment. Pre-hospital environment. The pre-hospital use rate is increasing. LMA is an important part of managing difficult airways in the eddy current method. Clinicians will increasingly face the dilemma of managing patients who have installed LMA but still require endotracheal intubation (ETT) to fix their airways. The intubation of the flexible endoscope through the LMA is simpler than the intubation of the awake flexible endoscope. In addition, intubation flexible endoscopes are becoming more available and affordable (now single-use), making them feasible for use outside the scope of operating rooms and intensive care units. The author aims to introduce clinicians to the indications, physical characteristics, and insertion/removal techniques associated with the new device Rescue™ ETT (Genesis Airway Innovations®, Sunshine Coast, Australia), which is specifically designed for intubation through LMA. Endoscopes and compare them with current equipment used for this purpose. Keywords: laryngeal mask airway, intubation, fiber optic, emergency, airway, scope, vortex
Archie Brain introduced the laryngeal mask airway, or LMA-Classic, in 1987.1. Soon, people realized the need to use LMA as an intubation catheter for endotracheal intubation. LMA-Classic is not suitable. The airway tube is too narrow and long to reliably place the endotracheal tube (ETT) at the distal end of the vocal cords. It is difficult to remove the LMA on the ETT after intubation. Recognizing the importance of using ETT to protect the airway after LMA placement, in 1997, ten years later, Brain produced intubated LMA and specific endotracheal tubes, 2 LMA-Fastrach™ and Fastrach™ ETT (both Teleflex®, Westmeath, Ireland). Since then, a variety of laryngeal mask airways dedicated to this purpose have been produced (Ambu AuraGain™ Air-Q™, C Trach™ and Unique Evo™), which Sorbello eloquently describes in "The Evolution of the Glottis" The evolution of the LMA airway device: Darwin's perspective. "The Fastrach™ ETT designed by 3 Brain is still the only widely commercially available ETT designed for intubation through LMA. The development of ETT for intubation through LMA may be overlooked and needs to withstand the same evolutionary pressure.
When poor tolerance to apnea was expected, the use of flexible endoscopes through the LMA intubation 4 in the modified Baileys procedure was recognized as the main technique. Clinicians will increasingly face the dilemma of managing patients who have installed LMA but still need ETT to protect their airways (Table 1). Table 1 Comparison of two current devices, namely Fastrach ETT™ and Aintree Intubating Catheter™ (AIC) and Rescue ETT™, a new device that recommends intubation through the laryngeal mask airway through a flexible endoscope
Table 1 Comparison of two current devices, namely Fastrach ETT™ and Aintree Intubating Catheter™ (AIC) and Rescue ETT™, a new device that recommends intubation through the laryngeal mask airway through a flexible endoscope
When Brain designed the ETT to be compatible with the intubation LMA, a major issue was the angle at which the ETT exits from the LMA mask hole so that it aligns with the vocal cords and trachea to assist blind intubation. The ideal tube was found to be a straight, flexible cord reinforced silicone ETT with a soft tapered Tuohy tip-Fastrach™ ETT (Teleflex®, Westmeath, Ireland).
Although blind airway intubation through a laryngeal mask can reduce the trauma to the larynx and increase the first intubation, it is currently recommended to use a flexible endoscope to achieve tracheal intubation. 5,6
When designing an ETT suitable for intubation on a flexible endoscope through an LMA, the following features are considered important: The tip and bevel must be suitable for successful intubation for the first pass. The drape (Figure 1) may occur at the level of the prickle muscle/epiglottis fold, or on the anterior wall of the trachea. 7 Studies have shown that backward-facing slopes, 8-11 tapered or hemispherical 12, and softer tips are superior. 12 When using an ETT with a lateral slope, rotate the catheter 90 degrees counterclockwise (the slope becomes Backward) can relieve hanging up, but may cause serious trauma, and even complete airway obstruction for awake patients. 13 Therefore, many clinicians recommend rotating the endotracheal tube 90 degrees counterclockwise before attempting intubation. The ETT needs to be long enough to be placed under the cord at the proximal end of the carina. The standard ETT is inappropriate. The axial length of most laryngeal masks 3 to 5 is 19-20 cm. The distance from the airway tube hole in the mask to the vocal cords varies from 2 to 4.7 cm in adults. 14 For the lower edge of the ETT cuff 2 cm below the vocal cords, the length of the cuff from the ETT to the proximal edge should be 20+4.7+2=26.4 cm. The pre-formed nasal cavity RAE and microlaryngeal ETT are longer than the standard oral ETT, and intubation through the laryngeal mask airway has been advocated. 15 ETT is best made of soft material (for example, silicone). The softer ETT can reduce trauma to the larynx and trachea, and make the catheter conform to the flexible endoscope, reducing hanging up, especially at the front wall of the trachea. 11,12 The LMA must be easily removed through the ETT. The 15 mm connector of the ETT must be detachable. Continuous airway safety to minimize interruption of ventilation and oxygenation during surgery is of paramount importance. The technique should be simple, with minimal procedural steps, easy to learn and implement, without frequent practice. The ability to use a flexible endoscope to verify the position of the ETT until after the laryngeal mask airway is withdrawn would be advantageous. The ETT should be suitable for long-term intubation, using a high-capacity low-pressure cuff made of polyvinyl chloride (PVC), without the need for steel wire reinforcement. Figure 1 Comparison of a standard ETT slope with a lateral slope (left) and Rescue™ ETT (right) illustrates the mechanism to reduce "hanging up" in the throat. Note: Take a probe in the lumen of the ETT to simulate a similar mechanism that occurs with a flexible endoscope. The equipment should be affordable to allow regular practice and universal availability.
Figure 1 Comparison of a standard ETT slope with a lateral slope (left) and Rescue™ ETT (right) to illustrate the mechanism for reducing throat "hang-up".
Note: Take a probe in the lumen of the ETT to simulate a similar mechanism that occurs with a flexible endoscope.
The ID of Rescue™ and Fastrach™ ETT (see Table 1) is limited to a maximum of 8 mm through the airway tube of the LMA. There is evidence that with current ventilators, a smaller ID ETT is sufficient. 18 Except for critically ill patients who require long-term intubation, women need 8 mm ID ETT and men need 9 mm ID ETT. Using a large diameter ETT can cause damage to the larynx and trachea. 18 When using the Aintree Intubation Catheter (AIC), an ETT with an inner diameter greater than 8 mm can be used, but 7 mm is the smallest inner diameter suitable for AIC, which limits its use in pediatric patients. The ID size of Rescue™ ETT is 5.5 to 8 mm, and the size of Fastrach ETT is 6 to 8 mm, which can be used for pediatric patients and adults.
The 8 mm ID Fastrach™ ETT measures 25 cm from the proximal end of the tube to the upper edge of the cuff. The i-gel™ laryngeal mask airway (No. 5) is used as a 20 cm airway tube. For tall patients, add 4.7 cm14 to make the distance between the hole in the mask and the vocal cords 24.7 cm. This makes the Fastrach™ ETT too short to be placed reliably under the vocal cords in the trachea. When the Rescue™ ETT (Figure 2A) is combined with the airway catheter, the minimum length to the upper edge of the cuff is 34 cm (Figure 3). Even for very tall patients, it can be placed at a sufficient depth, AIC length (56 cm) may be too short to pass through the ETT in very tall patients. 19 Figure 2 (A) Components of Rescue™ TM ETT (PVC). (A) Airway tube. (B) 15 mm ISO connector. (C) ETT with backward slope. (B) Insert the RESCUE™ ETT through the I-GEL™ laryngeal mask airway. Figure 3 shows a schematic diagram showing how to insert the Rescue™ ETT through the i-gel™ laryngeal mask airway. Remarks: Rescue™ ETT; a method of using a flexible endoscope. (A) LMA is used to protect the airway. (B) Choose a Rescue™ ETT of a suitable size (the selected ETT must not be forced to pass through the axis of the LMA because it may damage the cuff of the ETT). (C) The 15 mm ISO connector is removed from the ETT and connected to the airway pipe. The proximal end of the ETT and cuff is well lubricated. (D) The self-sealing connector with side arms is placed on the 15 mm connector of the airway tube. Choose a flexible cannula endoscope with a working length of at least 60 cm and a diameter that is close enough to be close to the bend-free tip of the ETT. The complex is then loaded on the endoscope with the tip of the endoscope just close to the tip of the ETT. (E) LMA has been disconnected. Then connect the ETT/airway catheter to the anesthesia machine and insert the distal ETT into the shaft of the LMA. Once the tip of the ETT tube is 2 cm away from the distal LMA hole, the cuff of the ETT is inflated in the shaft of the LMA, allowing continued ventilation. (F) Then push the flexible endoscope through the vocal cords and into the trachea. The cuff of the ETT is deflated and the ETT/airway catheter is laid on the endoscope until the cuff of the ETT is at a safe distance below the vocal cords and the cuff is reinflated. (G) The ETT/airway tube is stable. Deflate the LMA cuff and carefully remove it through the ETT/airway intubation. (H) Disconnect the ETT and the airway tube, remove the airway tube from the shaft of the LMA, and then deliver the inflation line, pilot balloon and inflation valve through the shaft of the LMA. (I) Insert the 15 mm connector into the proximal ETT tube and connect the patient to the ventilator.
Figure 2 (A) Components of Rescue™ TM ETT (PVC). (A) Airway tube. (B) 15 mm ISO connector. (C) ETT with backward slope. (B) Insert the RESCUE™ ETT through the I-GEL™ laryngeal mask airway.
Figure 3 shows a schematic diagram showing how to insert the Rescue™ ETT through the i-gel™ laryngeal mask airway.
Remarks: Rescue™ ETT; a method of using a flexible endoscope. (A) LMA is used to protect the airway. (B) Choose a Rescue™ ETT of a suitable size (the selected ETT must not be forced to pass through the axis of the LMA because it may damage the cuff of the ETT). (C) The 15 mm ISO connector is removed from the ETT and connected to the airway pipe. The proximal end of the ETT and cuff is well lubricated. (D) The self-sealing connector with side arms is placed on the 15 mm connector of the airway tube. Choose a flexible cannula endoscope with a working length of at least 60 cm and a diameter that is close enough to be close to the bend-free tip of the ETT. The complex is then loaded on the endoscope with the tip of the endoscope just close to the tip of the ETT. (E) LMA has been disconnected. Then connect the ETT/airway catheter to the anesthesia machine and insert the distal ETT into the shaft of the LMA. Once the tip of the ETT tube is 2 cm away from the distal LMA hole, the cuff of the ETT is inflated in the shaft of the LMA, allowing continued ventilation. (F) Then push the flexible endoscope through the vocal cords and into the trachea. The cuff of the ETT is deflated and the ETT/airway catheter is laid on the endoscope until the cuff of the ETT is at a safe distance below the vocal cords and the cuff is reinflated. (G) The ETT/airway tube is stable. Deflate the LMA cuff and carefully remove it through the ETT/airway intubation. (H) Disconnect the ETT and the airway tube, remove the airway tube from the shaft of the LMA, and then deliver the inflation line, pilot balloon and inflation valve through the shaft of the LMA. (I) Insert the 15 mm connector into the proximal ETT tube and connect the patient to the ventilator.
AIC is an airway exchange catheter (AEC), and FOB is usually recommended for intubation. The concern is safety. The literature shows that the complication rate of these products is very high, as high as 60%. 20-22 pneumothorax, the incidence rate is as high as 11%, 23 is a known complication of high-pressure jet ventilation caused by barotrauma, automatic PEEP and dynamic hyperinflation. However, it has been reported that the use of AEC without high-pressure jet ventilation can cause pneumothorax. 24,25
We recommend that AEC should only be used by teams that are versatile and trained in their use.
A potential problem with Rescue™ ETT is that the airway intubation and ETT are uncoupled during the operation (Figure 2A and B), but the force applied during intubation then withdraws the LMA on the ETT/airway complex to maintain this The role of coupling.
When using the Rescue™ ETT (Figure 3), the side arm of the self-sealing connector is placed on the 15 mm connector of the airway tube connected to the ETT. Then insert the flexible endoscope into the complex with the tip of the endoscope just close to the end of the ETT. Then connect the side arm of the self-sealing connector to the ventilator. The lubrication cuff of the ETT usually forms a sufficient seal with the airway tube of the LMA to allow continuous ventilation during intubation, or if the tip of the endoscope just exits the airway tube of the laryngeal mask, the cuff of the ETT can be inadequately sealed. The airway tube of the LMA is inflated, and before the ETT passes through the endoscope and into the trachea, the cuff is deflated to begin ventilation. Continue to ventilate while withdrawing the LMA and leave the flexible endoscope in place until the LMA is fully withdrawn to confirm that the ETT is still placed at the correct depth.
Fastrach™ ETT requires interruption of ventilation and at the same time withdrawing the laryngeal mask airway through the solid stabilizer bar, and then repeat the observation to confirm that the ETT has not migrated.
According to the literature review, it is clear that an ETT with a rear-facing bevel and a curved or tapered tip centered the tube on the oscilloscope and reduced hanging. It is an ideal choice for intubation through a flexible endoscope, and its use is discouraged. Current standard ETT for inclined planes.
The newly described Rescue™ ETT is a simple and safe device that uses simple technology to deploy. Rescue™ ETT retains all the advantages of Fastrach™ ETT, as shown in this article, it has several advantages over Fastrach™ ETT and Aintree Intubation Catheter™. Before being introduced into clinical practice, clinical studies are required to verify these claims.
All authors have made significant contributions to the work of the report, whether in terms of concept, research design, execution, data acquisition, analysis, and interpretation, or in all these areas; participating in drafting, revising, or critically reviewing articles; final approval requirements Published version; agreed on the journal to which the article was submitted; and agreed to be responsible for all aspects of the work.
This research did not receive any specific funding from public or commercial funding agencies; or non-profit sectors.
Vernon H Vivian is a director of Genesis Airway Innovations Pty Ltd, which holds patents for these devices. André Van Zundert, Tyson L Pardon and Samuel Vivian reported no conflicts of interest in this work.
1. Van Zundert TCR, Brimacombe JR, Ferson DZ, Bacon DR, Wilkins DJ. Archie Brain: Celebrating 30 years of laryngeal mask airway development. anaesthetization. 2012; 67: 1375-1385. doi:10.1111/anae.12003.x
2. Brain AI, Verghese C, Addy EV, Kapila A. Intubation laryngeal mask: develop a new tracheal intubation device. Br J Anaesth. 1997;79:699-703. doi:10.1093/bja/79.6.699
3. Sorbello M. The evolution of the supraglottic airway: Darwin's view. Minerva Anestesiol. 2018;84:699-703.
4. Sorbello M, Cortese G, Gaconnet C, Skinner M. The improved Bailey operation with LMA Protector™ is used for the supraglottic airway continuum. J Anaesth, India. 2019;63:78-80. doi:10.4103/ija.IJA_502_18
5. Noppens RR, Pius J. Blind intubation using supraglottic device: why should we try? Can J Anaesth. 2019; 66: 629-632. doi:10.1007/s12630-019-01352-5
6. Higgs A, McGrath BA, Goddard C, Rangasami J, Sunthalingam G, Gale R. Cook TM, and on behalf of the Difficult Airway Association, Intensive Care Association, School of Intensive Care, Royal College of Anesthesiologists: Guidelines for Tracheal Intubation in Critically Ill Adults Management. Br J Anaesth. 2018; 120: 323-352.
7. Johnson DM, from AM, Smith RB, from RP, Maktabi MA. Endoscopic study of the mechanism of failure of endotracheal tube into trachea during awake fiber-optic intubation. Anesthesiology. 2005;102:910-914. doi:10.1097/00000542-200505000-00008
8. Jafari A, Gharaei B, Reza Kamranmanesh M, etc. Comparison of steel wire-reinforced tracheal intubation and Parker elbow tube for oral fiber optic intubation: a randomized clinical trial. Minerva Anestesiol. 2014;80:324-329.
9. Bararka A, Rizk M, Muallem M, Bizri SH, Ayoub C. Used for the posterior and lateral bevel tracheal catheters of fiber optic intubation. Can J Anaesth. 2002;49:889-890. doi:10.1007/BF03017434
10. Ho A, Mizubuti G. Tracheal intubation: the evidence is in an oblique plane. J Emerg Med. 2018; 55: 821-826. doi:10.1016/j.jemermed.2018.09.001
11. Su K, Gao X, Xue FS, Ding GN, Zhang Y, Tian M. Difficulty in passing tracheal tube and subglottic airway injury during intubation of Glidescope video laryngoscope: a randomized controlled comparison of three tracheal tubes. anaesthetization. 2017; 72: 504-511. doi:10.1111/anae.13755
12. Ruari Greer J, Smith SP, Strang T. Comparison of endotracheal tube tip design and tracheal intubation channel during oral fiber intubation. Anesthesiology. 2001;94:729-731. doi:10.1097/00000542-200105000-00007
13. Sato S, Asai T, Hashimoto Y, Arai T, Okuda Y. Airway obstruction when awake patients try fiber intubation. Shengjing. 2014;63:548-551.
14. Pennant JH, Josh GP. Intubate the airway through a laryngeal mask. Anesthesiology. 1995; 83: 891-892. doi:10.1097/00000542-199510000-00048
15. Preis CA, Pries IS. Super-atmospheric intubation and airway intubation through a laryngeal mask. Anesthesiology. 1997; 87:187. doi:10.1097/00000542-199707000-00044
16. Henninger A, Krueger WA, Dieteric HJ, Konigsrainer I, Schroeder TH. The use of hollow fiber airway exchange catheters is a complication of tracheal tube exchange in critically ill patients. Acta anesthetic scan. 2008; 52: 1031. doi:10.1111/j.1399-6576.2008.01686.x
17. Evans H, Hodzovic I, Latto IP. Tracheal tube: Choose and use carefully. anaesthetization. 2010; 65:859. doi:10.1111/j.1365-2044.2010.06432.x
18. Farrow S, Farrow C, Soni N. Size is important: choose the correct endotracheal tube. anaesthetization. 2012; 67: 815-819. doi:10.1111/j.1365-2044.2012.07250.x
19. Gruenbaum SE, Gruenbaum BF, Tsaregorodtsev S, Dubilet M, Melamed I, Zlotnik A. The use of exchange catheters facilitates a new use for the intubation of Antry catheters in tall patients predicted to have a difficult airway: a case report. J Med Case Rep. 2012;6(1):1-5.
20. Benumov JL. Airway exchange catheter: simple concept, potentially huge danger. Anesthesiology. 1999; 91: 342-344. doi:10.1097/00000542-199908000-00005
21. Baraka AS. In tension pneumothorax, jet ventilation is complicated by the Cook airway exchange catheter. Anesthesiology. 1999;91:557-558. doi:10.1097/00000542-199908000-00031
22. Mott TC. Continuous airway access with difficult extubation: the efficacy of an airway exchange catheter. Anesthesia analysis. 2007;105:1357-1362. doi:10.1213/01.ane.0000282826.68646.a1
23. Cooper RM. Use endotracheal ventilation catheters to treat difficult extubation. Can J Anaesth. 1996; 43: 90-93. doi:10.1007/BF03015965
24. Harris K, Chalhoub M, Maroun R, Elsayegh D. Endotracheal tube exchanger: should we look for safer alternatives. Cardiopulmonary. 2012; 41: 67-69. doi:10.1016/j.hrtlng.2011.06.005
25. Duggan LV, Law JA, Murphy MF. Supplementary oxygen through the airway exchange catheter: efficacy, complications and recommendations. Can J Anaesth. 2011; 58: 560-568. doi:10.1007/s12630-011-9488-4
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and include the Creative Commons Attribution-Non-commercial (unported, v3.0) license. By accessing the work, you hereby accept the terms. The use of the work for non-commercial purposes is permitted without any further permission from Dove Medical Press Limited, provided that the work has an appropriate attribution. For permission to use this work for commercial purposes, please refer to paragraphs 4.2 and 5 of our terms.
Contact Us• Privacy Policy• Associations and Partners• Testimonials• Terms and Conditions• Recommend this site• Top
Contact Us• Privacy Policy
© Copyright 2021 • Dove Press Ltd • Software development of maffey.com • Web design of Adhesion
The views expressed in all articles published here are those of specific authors and do not necessarily reflect the views of Dove Medical Press Ltd or any of its employees.
Dove Medical Press is part of Taylor & Francis Group, the academic publishing department of Informa PLC. Copyright 2017 Informa PLC. all rights reserved. This website is owned and operated by Informa PLC ("Informa"), and its registered office address is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 3099067. UK VAT group: GB 365 4626 36
In order to provide our website visitors and registered users with services that suit their personal preferences, we use cookies to analyze visitor traffic and personalize content. You can understand our use of cookies by reading our privacy policy. We also retain data about visitors and registered users for internal purposes and to share information with our business partners. By reading our privacy policy, you can understand which of your data we retain, how to process it, with whom to share it, and your right to delete data.
If you agree to our use of cookies and the content of our privacy policy, please click "Accept".