Intubating LMA

OVERVIEW

  • the intubating LMA (Fastrach™) is a specially designed supraglottic airway device (SAD) that can be used as a conduit to facilitate intubation

USES

  • rescue device for failed intubation (i.e.. the “can’t intubate can ventilate” situation)
  • rescue device for difficult bag-mask ventilation
  • primary or alternate strategy for intubation
    • e.g. elective management of the known difficult airway
    • e.g. patients with known cervical spine injuries (ILMA use results in less spinal movement than direct laryngoscopy)

DESCRIPTION

  • a rigid curved airway tube
  • rigid handle for one-handed insertion in any patient position and helps ensure appropriate alignment
  • air filled LMA cuff with epiglottic elevator bar
  • dedicated wire-reinforced silicone tracheal tube with low volume high pressure cuff, ranging in sizes from 6.0 to 8.0 mm internal diameter
  • Stabilising rod
  • Single use and reusable models
  • Sizes 3 (30-50kg; 20mL cuff), 4 (50-70kg; 30 mL cuff) and 5 (70-100kg; 40 mL cuff)

METHOD OF INSERTION/ USE

Insert ILMA

  • deflate ILMA cuff
  • lubricate ILMA mask on the posterior surface using water soluble lubricant and rub the lubricant over the anterior hard palate
  • release cricoid pressure (if present) prior to inserting the iLMA
  • insert ILMA holding the handle in a circular movement, maintaining contact against the curve of the palate and posterior pharynx
  • Never use the handle as a lever
  • release handle then inflate iLMA cuff to a pressure of approximately 60 cm H2O (usually less than maximum cuff capacity)

Optimise position for intubation

  • Grasp the handle of the device and gently ventilating the patient
  • Squeezing the bag, and gently rotating the handle in and out and side to side until ventilation is optimized
  • Gently lifting the handle anteriorly (in a similar fashion as a laryngoscope) and begin passing the lubricated ETT

Placement of endotracheal tube

  • Hold the ILMA device handle while gently inserting the lubricated ETT into the airway shaft
  • Advance the ETT, inflate the cuff and confirm intubation using ETCO2

Removal of the ILMA, leaving the endotracheal tube in position

  • Remove the ETT connector and ease the ILMA out by gently swinging the handle caudally
  • Use the stabilizing rod to keep the ETT in place while removing the ILMA until the ETT can be grasped at the level of the incisors
  • Remove the stabilizing rod and gently unthread the inflation line and pilot ballon of the ETT
  • Replace the ETT connector
  • NB. ETT is often in too deep following insertion via an ILMA, ETT often needs to be pulled back (check the distance at the teeth and confirm on CXR)

Video from HQMEDED demonstrating insertion of iLMA, intubation through iLMA and removal of iLMA:

CONTRA-INDICATIONS

Relative contra-indications include patients who are difficult to insert or ventilate LMAs in (e.g. RODS):

  • restricted mouth opening
  • obese or obstructed airway
  • deformed airway anatomy
  • ‘stiff’ necks or lungs (arthritic necks, poor lung compliance)

In these circumstances an LMA may have a role in airway management, but the risk of failure is higher

COMPLICATIONS

  • oropharyngeal trauma
  • esophageal intubation
    • up to 8% when performing blind intubation via ILMA (Demetriou et al ,1999)
    • due to esophageal inlet being included in the bowl of the LMA
  • failure to pass endotracheal tube, due to:
    • ILMA placed too deep
    • ETT impaction in the vallecula
    • folded over epiglottis
    • epiglottis is out of the reach of the EEB (Epiglottic Elevating Bar) (LMA size is too small)
    • ILMA malalignment
    • inadequate sedation and/or neuromuscular blockade
    • poor positioning of the head and neck

OTHER INFORMATION

Trouble-shooting difficulty passing the endotracheal tube

  • resistance immediately at the 15cm mark: if iLMA seated too deeply, try withdrawing the device slightly or change to a smaller size iLMA
  • resistance 2cm distal to the 15cm mark: rotate ETT bevel to prevent impaction in the vallecula
  • resistance 2cm distal to the 15cm mark: withdraw 5cm and reinsert if a folded over epiglottis is suspected (allows epiglottis to unfold) (aka ‘the up-down manoeuvre’)
  • resistance at 3cm distal to the 15cm mark: use larger LMA size if epiglottis is out of the reach of the EEB (Epiglottic Elevating Bar)
  • resistance at 4cm distal to the 15cm mark: use smaller LMA size (typically in pateints with short, wide necks)
  • if iLMA is misaligned/malrotated, perform the Chandy manoeuvre (as described by Chandy Verghese):
    • “The metal handle is used to rotate the device in the sagittal and/or coronal planes to establish optimal ventilation with minimal resistance to bag ventilation and audible “leaks” during manual ventilation. In the optimal position, audible leakage of the gas mixture from the circuit will be minimal. The handle is held in this position and optimizes the passage of the tracheal tube.”
    • “The second step is to use the handle to lift (but not tilt) the LMA Fastrach away from the posterior pharyngeal wall.”
    • “The first step enables optimal alignment of the laryngeal aperture and the bowl of the mask, and the second facilitates smooth passage of the dedicated endotracheal tube (ETT)”

Intubation can be performed using standard Mallinckrodt PVC endotracheal tubes, though this is not recommended by the ILMA manufacturer

  • ensure the ETT is well lubricated
  • insert with the curvature of the ETT in reverse orientation to the curvature of the ILMA as this decreases the angle of emergence of the ETT from the ILMA and increases intubation success rates
  • insertion takes about 4 seconds longer on average, and is more likely to require additional manoeuvres
  • up to size 8-0 tube can be used with a size 5 ILMA
  • a standard ETT may be preferred to a Fastrach endotracheal tube as the low volume high pressure cuff may be more likely to cause tracheal mucosal injury with longterm use

Success rates

  • blind insertion has success rates as high as 96.4% in difficult to intubate patients after 3 attempts (Ferson et al, 2001)
  • first pass success rate may be as low as 64-75% in patients with anticipated, known or unanticipated difficult airways
  • novices can achieve high success rates, although about 20 intubations may be required to achieve expertise
  • bronchoscopic-assisted intubation via an ILMA has close to 100% success (improved first attempt and overall success rates

ILMA can be used in awake patients with topicalised airways, as demonstrated by Chandy Verghese (on himself!) in this video:

REFERENCES AND LINKS

LITFL

Journal articles

  • Caponas G. Intubating laryngeal mask airway. Anaesth Intensive Care. 2002 Oct;30(5):551-69. PMID: 12413253
  • Dimitriou V, Voyagis GS. Blind intubation via the ILMA: what about accidental oesophageal intubation? Br J Anaesth. 1999 Mar;82(3):478-9. PMID: 10434838
  • Joo HS, Kapoor S, Rose DK, Naik VN. The intubating laryngeal mask airway after induction of general anesthesia versus awake fiberoptic intubation in patients with difficult airways. Anesth Analg. 2001 May;92(5):1342-6. PMID: 11323374.
  • 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; 95:1175-81.
  • Komatsu R, Nagata O, Sessler DI, Ozaki M. The intubating laryngeal mask airway facilitates tracheal intubation in the lateral position. Anesth Analg. 2004 Mar;98(3):858-61 PMC1350644.
  • Kundra P, Sujata N, Ravishankar M. Conventional tracheal tubes for intubation through the intubating laryngeal mask airway. Anesth Analg. 2005 Jan;100(1):284-8. PMID: 15616092.
  • Levitan RM, Ochroch EA, Stuart S, Hollander JE. Use of the intubating laryngeal mask airway by medical and nonmedical personnel. Am J Emerg Med. 2000 Jan;18(1):12-6. PMID: 10674524.
  • Pandit JJ, MacLachlan K, Dravid RM, Popat MT. Comparison of times to achieve tracheal intubation with three techniques using the laryngeal or intubating laryngeal mask airway. Anaesthesia. 2002 Feb;57(2):128-32. PMID: 11871949.
  • Sahin A, Salman MA, Erden IA, Aypar U. Upper cervical vertebrae movement during intubating laryngeal mask, fibreoptic and direct laryngoscopy: a video-fluoroscopic study. Eur J Anaesthesiol. 2004 Oct;21(10):819-23. PMID: 15678738.
  • Sharma MU, Gombar S, Gombar KK, Singh B, Bhatia N. Endotracheal intubation through the intubating laryngeal mask airway (LMA-Fastrach™): A randomized study of LMA- Fastrach™ wire-reinforced silicone endotracheal tube versus conventional polyvinyl chloride tracheal tube. Indian J Anaesth. 2013 Jan;57(1):19-24. PMC3658329.
  • Timmermann A, Russo SG, Crozier TA, Nickel EA, Kazmaier S, Eich C, Graf BM. Laryngoscopic versus intubating LMA guided tracheal intubation by novice users–a manikin study. Resuscitation. 2007 Jun;73(3):412-6. PMID: 17343972.
  • Verghese, C. Laryngeal MAsk Airway Devices: Three Maneuvers For Any Clinical Situation. Anesthesiology News Guide to Airway Management 2010;15-16
  • Zhu T. Conventional endotracheal tubes for intubation through the intubating laryngeal mask airway. Anesth Analg. 2007 Jan;104(1):213; author reply 213-4. PMID: 17179279.

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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