Plan B
THIS SKILL STATION COVERS:

Videobronchoscope assisted intubation via the Berman airway

Videobronchoscope assisted intubation via Supraglottic Airway Devices

Videobronchoscope assisted intubation via Supraglottic Airway Devices using an Aintree Intubating Catheter

Use of the Intubating LMA (Fastrach™) with videobronchoscopic guidance

Use of the Intubating LMA for blind intubation

The indications, contraindications and complications of these techniques, and their role within the DAS guidelines

THE EQUIPMENT

THE BERMAN AIRWAY
THE COOK AINTREE INTUBATING CATHETER
THE CLASSIC LMA
THE PROSEAL LMA
THE IGEL
THE AURAGAIN
THE INTUBATING LMA

THE ESSENTIALS

Videobronchoscopic intubation via a conduit is a relatively low skill technique that can be very useful in the management of the difficult airway, both anticipated and unanticipated. In the case of the unanticipated difficult airway, it might form part of Plan B of the DAS guidelines (the “can’t intubate can ventilate” situation). In terms of the Vortex approach, videobronchoscopic conversion of a supraglottic airway device (SAD) into a tracheal tube is a Green Zone conversion strategy, which is inherently of lower risk than a replacenent strategy, as the initial green zone device (the SAD) is left in place.

The technique can also be used electively in the management of the known difficult airway and in patients with C-spine injuries.

The conduits used for this technique include supraglottic airway devices (SADs), of which there are many types, and specifically designed oral airways (such as the Berman airway).

Several SADs have been used successfully for this purpose, including the classic LMA™, ILMA, AuraGain™ and Proseal LMA™, but the i-gel™ seems to be the most reliable.1-3 Blind success rates with SADs are low and are not recommended.3

There are many examples in the literature of successful difficult airway management using the Aintree Intubating Catheter™ (AIC) in combination with the classic LMA, the i-gel and the Proseal LMA.4,5 Evidence suggests that passage of the AIC via the Proseal LMA is as easy and reliable as via the classic LMA.6 The Supreme LMA™ does not seem to be suitable for this purpose as the angle of exit of the AIC from the device is unpredictable due to the epiglottic fins in its bowl.7

After successfully inserting a tracheal tube through a SAD, it is tempting to try to remove the SAD, leaving the tube in place. This is not recommended,8 except in the case of the ILMA, as this device is specifically designed to be removed and comes with a stabilising rod to facilitate the procedure. During anaesthesia for surgery, the SAD is very unlikely to cause harm.9 If intubation is to be prolonged, an airway exchange catheter can be used to facilitate SAD removal.

THE INTUBATING LMA

Use of the intubating LMA has become less common is recent years due to the advent of SADs specifically designed for videobronchoscopic conversion (e.g. the i-gel and Auragain), and the increased availability of videobronchoscopes. However, the ILMA remains an excellent conduit for tracheal intubation. It is used in Plan B of the DAS guidelines but can also be useful in the elective management of the known difficult airway and in patients with C-spine injuries. In the latter group, fluoroscopic and ultrasound studies have demonstrated decreased movement of the cervical spine with the ILMA than direct laryngoscopy with manual in-line stabilisation.10,11 The ILMA can be used for blind intubation,12 but should be used in conjunction with a videobronchoscope wherever possible, as success rates are higher, and videobronchoscopic techniques are always superior to blind techniques3

  • Blind insertion in patients without difficult airways: 95.7%.12
  • Blind insertion in patients with known or anticipated difficult airways: 64% first pass, 92% overall, other 8% achieved with bronchoscopic technique.13
  • In unanticipated difficult airways: one study of 23 patients – 75% first pass blind insertion, 100% overall insertion.13

A learning curve of about 20 insertions has been described,14 and studies with novice users suggest that high success rates can be achieved with minimal training.15,16

Standard Portex or Mallinckrodt PVC tubes can be used successfully with the device,17 and if used, should be inserted in the reverse orientation (against their natural curve), as this decreases the angle of emergence of the device and improves insertion rates.18

Features of different supraglottic airway devices

SAD / tube compatibilities

Top Tips

  • If difficulties placing supraglottic airway device, ensure head in neutral position, reduce or remove cricoid pressure, try withdrawing by 4 – 5cm then reinserting, ensure adequate sedation/relaxation.
  • Use of tubes other than those in Table 2 increases the risk of the cuff sitting above or at the level of the vocal cords and therefore the chance of accidental extubation.
  • The aperture bars of a classic LMA can be removed with a scalpel or scissors to facilitate the passage of the tracheal tube.
  • Use of the Aintree Intubating Catheter is preferable because:
    • It enables the insertion of larger tracheal tubes
    • It allows removal of the SAD
    • It reduces the likelihood of the tracheal tube getting caught on the classic LMA aperture bars
    • It enables oxygenation via the Rapi-fit™ connector in case of difficulty passing tracheal tube
  • Blind techniques should be avoided whenever possible. Only use the ILMA for blind intubation if a videobronchoscope is not available.
  • If tube not passing during blind ILMA technique, try Chandy manoeuvre or withdraw ILMA slightly
  • ILMA can be reinserted (over tube left in place) for extubation to facilitate recovery and airway maintenance or enable deep extubation

Plan B - Video 1

Plan B - Video 2 (ILMA)

References

  1. Kleine-Brueggeney M, Theiler L, Urwyler N, Vogt A, Greif R. Randomized trial comparing the i-gel and Magill tracheal tube with the single-use ILMA and ILMA tracheal tube for fibreoptic-guided intubation in anaesthetized patients with a predicted difficult airway. British journal of anaesthesia. 2011;107(2):251-257.
  2. Shimizu M, Yoshikawa N, Yagi Y, et al. [Fiberoptic-guided tracheal intubation through the i-gel supraglottic airway]. Masui. 2014;63(8):841-845.
  3. Frerk C, Mitchell VS, McNarry AF, et al. Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. British journal of anaesthesia. 2015;115(6):827-848.
  4. Cook TM, Seller C, Gupta K, Thornton M, O’Sullivan E. Non-conventional uses of the Aintree Intubating Catheter in management of the difficult airway. Anaesthesia. 2007;62(2):169-174.
  5. Higgs A, Clark E, Premraj K. Low-skill fibreoptic intubation: use of the Aintree Catheter with the classic LMA. Anaesthesia. 2005;60(9):915-920.
  6. Blair EJ, Mihai R, Cook TM. Tracheal intubation via the Classic and Proseal laryngeal mask airways: a manikin study using the Aintree Intubating Catheter. Anaesthesia. 2007;62(4):385-387.
  7. Greenland KB, Tan H, Edwards M. Intubation via a laryngeal mask airway with an Aintree catheter – not all laryngeal masks are the same. Anaesthesia. 2007;62(9):966-967.
  8. Alexander R. Do not remove the laryngeal mask airway. Anesthesia and analgesia. 1999;89(2):536-537.
  9. Keller C, Brimacombe J. Mucosal pressure and oropharyngeal leak pressure with the ProSeal versus laryngeal mask airway in anaesthetized paralysed patients. British journal of anaesthesia. 2000;85(2):262-266.
  10. Sahin A, Salman MA, Erden IA, Aypar U. Upper cervical vertebrae movement during intubating laryngeal mask, fibreoptic and direct laryngoscopy: a video-fluoroscopic study. European journal of anaesthesiology. 2004;21(10):819-823.
  11. Gercek E, Wahlen BM, Rommens PM. In vivo ultrasound real-time motion of the cervical spine during intubation under manual in-line stabilization: a comparison of intubation methods. European journal of anaesthesiology. 2008;25(1):29-36.
  12. Caponas G. Intubating laryngeal mask airway. Anaesthesia and intensive care. 2002;30(5):551-569.
  13. Ferson DZ, Rosenblatt WH, Johansen MJ, Osborn I, Ovassapian A. Use of the intubating LMA-Fastrach in 254 patients with difficult-to-manage airways. Anesthesiology. 2001;95(5):1175-1181.
  14. Parr MJ, Gregory M, Baskett PJ. The intubating laryngeal mask. Use in failed and difficult intubation. Anaesthesia. 1998;53(4):343-348.
  15. Timmermann A, Russo SG, Crozier TA, et al. Laryngoscopic versus intubating LMA guided tracheal intubation by novice users–a manikin study. Resuscitation. 2007;73(3):412-416.
  16. Levitan RM, Ochroch EA, Stuart S, Hollander JE. Use of the intubating laryngeal mask airway by medical and nonmedical personnel. The American journal of emergency medicine. 2000;18(1):12-16.
  17. Kundra P, Sujata N, Ravishankar M. Conventional tracheal tubes for intubation through the intubating laryngeal mask airway. Anesthesia and analgesia. 2005;100(1):284-288.
  18. Zhu T. Conventional endotracheal tubes for intubation through the intubating laryngeal mask airway. Anesthesia and analgesia. 2007;104(1):213; author reply 213-214.

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