Five New Devices for the Difficult Airway Ron M. Walls, MD Brigham and Women’s Hospital Harvard Medical School The Difficult Airway

A Haiku Can’t intubate, can’t ventilate…Panic. Flail. Brain Cells New Devices for the Difficult Airway A Haiku Can’t intubate, can’t ventilate…Panic. Flail. Brain Cells die in bunches. The Difficult Airway

New Devices for the Difficult Airway Outline Magnitude of the problem Where do new devices fit in? New devices The Difficult Airway

Difficult Laryngoscopy: Cormack-Lehane Score The Difficult Airway

New Devices for the Difficult Airway Magnitude of the Problem: OR Grade 3 or 4 laryngoscopy < 5% True grade 4 laryngoscopy < 1% Impossible intubation 0.35% of “normals” “CICV” ~ 1:10,000 or 0.01% Patients are “pre-selected” NOT applicable to ED or out-of-hospital intubations Cormack, Karkouti, Langeron, Mallampati, Samsoon, Williams, Wilson, others The Difficult Airway

How common is difficult bag mask ventilation? In the OR (patients are pre-selected) Difficult BMV in 1.5 - 5% Impossible BMV in 0.16% Difficult BMV with difficult intubation in ~ 0.3% to 5% Difficult BMV makes DI 4x more common, and impossible intubation 12x Numbers not known for the ED, EMS Langeron O et al. Anesthesiology 2000 May 92 1229-1236. Kheterpal S et al. Anesthesiology 2006 Nov; 105:885-91. The Difficult Airway

New Devices for the Difficult Airway Outline Magnitude of the problem Where do new devices fit in? New devices The Difficult Airway

Where do new devices fit in? Historically considered novelties, “toys” Reserved for difficult, failed airways Late adopters vs early adopters The real question is… The Difficult Airway

Where do new devices fit in? If you had trained on, and used, a video laryngoscope, or a fiberoptic stylet, and DL was newly introduced: What would the studies show? Would you adopt the new technology? Would the lower cost matter? The Difficult Airway

Where do new devices fit in? If you had trained on, and used, a video laryngoscope, or a fiberoptic stylet, and DL was newly introduced: The studies? Clear inferiority! Would you adopt? No! Would the lower cost matter? No! The Difficult Airway

Where do new devices fit in? These are “every intubation” devices There is a learning curve The question is not whether, but which, and when? The Difficult Airway

New Devices for the Difficult Airway Outline Magnitude of the problem Where do new devices fit in? New devices The Difficult Airway

The future of difficult laryngoscopy? All difficult laryngoscopy definitions are based on direct laryngoscopy Most have to do with impossibility of creating “a line of sight” Video laryngoscopes will require an entirely new way of thinking The Difficult Airway

New Devices for the Difficult Airway Glidescope Video laryngoscope Minimal mouth opening required Very high intubation success rate Allows “teacher” to share view with “student” Portable, durable The Difficult Airway

New Devices for the Difficult Airway Glidescope The Difficult Airway

How good is the Glidescope? The Difficult Airway

Is there a learning curve? 728 patients, 133 operators, 18 months 133/728 had DL and GVL – GVL always equal or better view 35 with grade III/IV with DL; 24/35 better with GVL Failure 26/728 (3.6%), 14/26 had grade I views Cooper RM: Can J Anaesth 52:191, 2005. The Difficult Airway

For Routine Airways ? DL then GL on 400 elective anesth patients DL: 67%, 26%, 6%, 0.5% grades I-IV GL: 89.5%, 10.5%, 0%, 0% Success GL: 85.5%, 97.5%, 99.9% att 1-3 All <40 secs, mean 21 secs 1/400 not intubated despite Grade I view Tremblay M-H et al. Anesth Analg 2008 May; 106:1495. The Difficult Airway

For Novices ? 20 novice clinicians (paramedic students, PGY1 residents, nurses, med students) Demo then 3 successful intubations with DL and GVL on manikins 200 patients (5+5 each) 93% vs 51% success in <120 secs CL III/IV 8% vs 50%. Time 63 secs vs 89 secs Nouruzi-Sedeh P: Anesthesiology 110:32, 2009 The Difficult Airway

For C-Spine Injury ? 20 elective anesth patients with ILS 2 anesth residents with 30x experience Continuous fluoro CSpine movement comparable Grade 1: 50% v 0%, 2: 50% v 65%, 3: 0% v 35% Robitaille A: Anesth Analg 106:935, 2008. The Difficult Airway

Is there a learning curve? 728 patients, 133 operators, 18 months 133/728 had DL and GVL – GVL always equal or better view 35 with grade III/IV with DL; 24/35 better with GVL Failure 26/728 (3.6%), 14/26 had grade I views Cooper RM: Can J Anaesth 52:191, 2005. The Difficult Airway

McGrath Videolaryngoscope Videoscope with built in screen Blade design similar to GS Plastic sheath for blade Blade adjustable The Difficult Airway

McGrath in Clinical Studies Mostly case series and reports 143/150 patients Grade I, 6 Grade 2 98% intubation success No comparison studies (yet) Shippey B: British Journal of Anaesthesia 2008 100(1):116-119 Shippey B: Can J Anaesth 2007; 54:307-313. The Difficult Airway

Storz Video Laryngoscope Video/FO laryngoscope Based on standard blades Interchangeable video camera system Pediatric and adult blades High quality optics The Difficult Airway

Storz CMAC® (now released) The Difficult Airway

CMAC vs Storz VL Storz VL is fiberoptic coupled to CCD video CMAC is “pure” CMOS video Fogging vs no fogging Two cables vs one Expense Complexity Image quality The Difficult Airway

How good is the Storz VL? 54 patients have DL and SVL by exp anesth 7x greater force on maxillary incisers DL vs SVL 17% grade III/IV vs 0% Lee RA: Anesth Analg 108:187, 2009. The Difficult Airway

For learning ? 49 novice intubators on manikins with normal or Diff Airways, DL vs SVL 84% vs 54% first attempt success Less dental trauma Greater confidence, considered intubation less difficult than DL group Low D: Anaesthesia 63:195, 2008 The Difficult Airway

Pentax AWS® (not yet released in the US) Videoscope with preload tube channel Lenticle helps aim Light, portable The Difficult Airway

How good is the Pentax AWS? Better view, less CS movement than MAC 46/320 patients grade III/IV with MAC: 45 Grade I, 1 Grade IIa with AWS IDS with AWS 0 in 305, 1 in 14, 2 in 1 Decreased CS movement with bougie Enomoto Y: British Journal of Anaesthesia 2008 100(4):544-548 Suzuki A: Anaesthesia. 63(6):641-647, June 2008. Takenaka I: Anesthesiology 110:1335-40, June 2009. The Difficult Airway

Fiberoptic Stylets Storz Bonfils® Clarus Shikani Optical Stylet® Clarus Levitan® Stylet AirRIFL® All (except Levitan) avoid DL Rigid, + malleable Like lighted stylet, but “visual” Portable, have own light source The Difficult Airway

SOS Malleable FO Midline approach Inexpensive Video adaptable The Difficult Airway

SOS 55% less C-Spine movement than MAC DL 28 vs 17 seconds to intubate Better and faster than DL + bougie in manikin model Case reports, small series in children Turkstra TP et al. Can J Anesth 54:441; 2007. Evans A et al: Anaesthesia 61:478; 2006. The Difficult Airway

Air RIFL® New dynamically adjustable FO stylet Little/no research data No real clinical experience (yet) Cool entrepreneurial website, though The Difficult Airway

Bonfils Stylet Non-malleable Retro-molar approach Popular in N Europe Self contained High quality optics Higher price than SOS The Difficult Airway

New Devices for the Difficult Airway AirTraq® “Periscope” Mounted tube Disposable Maharaj CH et al., Anesthesiology 2007 Jul; 107:53-9. Maharaj CH et al., Anaesthesia 2008 Feb; 63:182. Hirabayashi Y et al., Anaesthesia 2008 Jun; 63:635. The Difficult Airway

Take home points? VL is superior to DL Shorter learning curve Better glottic views Equal or better on virtually every measure So, what is holding us back? The Difficult Airway

The Difficult Airway

And the Venerable Laryngoscope? The Difficult Airway

Prediction By 2010, a minority of ED intubations will be done New Devices for the Difficult Airway Prediction By 2010, a minority of ED intubations will be done using a conventional laryngoscope and blade. www.theairwaysite.com The Difficult Airway

New Devices for the Difficult Airway ventilate. Knew in advance. Another Haiku Can’t intubate. Can’t ventilate. Knew in advance. Plan rescues the life. www.theairwaysite.com The Difficult Airway

The Difficult Airway FIN The Difficult Airway