Video Laryngoscopy and its future in Airway Management Dr Jayaram K Dasan FRCA King s College Hospital, King s Health Partner, London, UK Page 1
Overview Introduction NAP4 DL Vs VLS VLS Mechanics Classification Advantage & disadvantage Current evidence on VLS Other uses of VLS Limitations and complications Future of VLS Conclusion
Where do I work?
Evidence from NAP4 Starts 1 st September 2008 Runs for 1 year Data Collection
Results of the second phase of NAP4: overall results and anaesthesia 2008-9 Primary airway problem NA P4 Report and findings of the 4th National Audit Project of The Royal College of Anaesthetists
Difficult airway Society 2015 guidelines The recently published DAS 2015 guidelines emphasize the importance of the first attempt at laryngoscopy to prevent airway trauma and progression to a CICO situation. (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: 827 48) Chance of success declines with each subsequent attempt at laryngoscopy The importance of first-pass success is arguably even greater in the critically ill patient, when multiple attempts at intubation lead to high rates of severe hypoxia and other life-threatening (or lifeending) complications. (Nolan JP, Kelly FE. Airway challenges in critical care. Anaesthesia 2011; 66(Suppl 2): 81 92)
Videolaryngoscopy (VLS): What is it? Videolaryngoscopy (VL) utilizes video camera technology to visualize airway structures and facilitate endotracheal intubation (ETI) Eliminating the need for a direct line of sight to visualize airway structures. In fact, this helps improve glottic visualization
VLS: How does it help in laryngeal view?
VLS: How do they do it? The viewing angle is increased from 15 degrees (Mac) during direct laryngoscopy into 60 degrees (VLS) during videolaryngoscopy Figure 1. From: Van Zundert et al. Videolaryngoscopy allows a better view of the pharynx and larynx than classic laryngoscopy. Br J Anaesth 2012; 109: 1014-1015. A. Direct Laryngoscopy (15 ); Indirect videolaryngoscopy (60 ) using a Macintosh-form blade (B) and a Difficult Curved D-Blade (C). Note: point of view starts where the optics are placed at the tip of the blade (B+C).
Laryngeal visualization- any better Comparison of three video laryngoscopy devices to Direct Laryngoscopy (DL) for intubating obese patients R. Yumul et al ; Journal of Clinical Anesthesia (2016) 31,71 77 A randomized controlled trial (30#4) Cormack Lehane grade (CL) CL 1 CL 2 CL 3 CL 4 DL 12 8 5 6 C- Mac 16 12 2 0 Glidescope 18 10 2 0 McGrath 23 7 0 0 Conclusion: The use of the Videolaryngoscopy for tracheal intubation of obese patients improved the visualization of the larynx.
Where does VLS score high in general population? Modified Cormack-Lehane classification CL Grade (visualisation) Description Approximate frequency. Likelihood of difficult intubation 1 Full view of glottis 68% <1% 2a Partial view of glottis 24% 4.3% 2b Only posterior extremity of glottis seen or only arytenoid cartilages 6.5% 67.4% 3 Only epiglottis seen, none of glottis seen 1.2% 87.5% 4 Neither glottis nor epiglottis seen very rare very likely
What does VLS offer: Benefits of videolaryngoscopy Videolaryngoscopy is undoubtedly one of the major advances in practical anaesthesia in recent years Standard mobile cell phones Vs smart phones 7 Several editorialists have called for videolaryngoscopy to be a first-line technique for airway management The role of videolaryngoscopy in difficult intubation has recently been recognized in the DAS 2015 guidelines DAS recommend that all anaesthetists are trained in videolaryngoscopy and that all anaesthetists have immediate access to a videolaryngoscope at all times.
What does VLS offer: Benefits of videolaryngoscopy Beyond anaesthesia, predictions have been made that videolaryngoscopy will dominate the field of emergency airway management in the future Sakles JC, Chiu S, Mosier J,Walker C, Stolz U. The importance of first pass success when performing orotracheal intubation in the emergency department. Acad Emerg Med 2013; 20: 71 8 It seems that cost is the main consideration holding back the tide
Advantages and Limitations of traditional laryngoscopy - DLS Historical back ground Need optimal laryngoscopy position Align oral, pharyngeal and laryngeal axes Hand eye co-ordination Extensive learning curve Difficult to teach 75 years of track record. Simple logistics
DLS: Any Pressure or increasing expectation? Still we fail to intubate and ventilate Increasing Medico-legal expenses Professional bodies& experts Advancement of technology around us Increasing expectation Patients Public institutions Regulatory bodies Limitations on training time
VLS: Advantages of video technology in difficult airways Clear picture on a display monitor View larynx, access to larynx & position of ETT Portable and main & battery operated Disposable and reusable consumables Easy to set up Cost and maintenance
VLS: Advantages of video technology in difficult airways O/P/L airway axis aligning not necessary Awake and intubation under GA Paediatric and adult use Elective and emergency use Easy to set and quick to use Easy to teach and learn Intubation in suboptimal conditions Minimal cervical manipulation First line/ front line/ backup? Team, communication, Human factors
Disadvantages of VLS Difficulty in passing ETT despite improved glottic visualization (especially with angulated blade) Possible increased intubation time Variable learning curve Potential weakening in development/maintenance of DL skill set, especially in non-experts Potential for false sense of security and lack of preparation for difficult airway
Disadvantages of VLS Two dimensional view with loss of depth perception Blind spot and bleeding Fogging and secretions on camera lens More complicated Need a stylet Expensive.
How many are they? So many and confusing
Video laryngoscope C-MAC 7 LCD display Reusable and disposable blades D-blade, Miller & Mac blades Adult and paediatric
VLS: GlideScope Portability & clarity Durable Antifog Recording
McGrath VL Scope Highly portable Battery operated Slim / Mac& curved blades
VLS: Kingvision Light weight Highly portable Battery operated Channelled and non-channelled blades
Pentax AWS Dual purpose built & portable
Optical laryngoscope: Airtraq Highly portable Battery operated Light weight Prism based Channelled
VLS classification group them (i) Devices with a Macintosh-like blade, such as C-MAC (Karl Storz Endoscopy, Slough, Berkshire, UK) McGrath Mac (Aircraft Medical, Edinburgh, UK) GlideScope MAC (Verathon Medical, Bothwell, WA, USA) AP Advance (Venner Medical International, St Helier, UK)
VLS classification ii) Devices with an extra-curved blade, such as AP Advance with difficult airway blade (Venner Medical) C-MAC D blade (Karl Storz Endoscopy) GlideScope (Verathon Medical) King Vision with standard blade (Ambu, St Ives, Cambridgeshire, UK) McGrath Mac with curved blade (Aircraft Medical)
VLS classification (iii) Devices with a channelled blade Airtraq Pentax AWS King Vision AP AWS Advance
Are they all the same All make larynx visible Some facilitate the passage of the ET tube or bougie into the larynx Some create more room to manoeuvre Some lift the tongue mass Some will illuminate the larynx better Some elevate the epiglottis
. You could be any where
It could be any kind
Morbid Obesity
The best evidence you get in Airway research
Evidence: Early clinical experience with a new video laryngoscope (GlideScope) Cooper RM, Pacey JA, 728 patients. METHODS: Five centres, involving 133 operators and a total of 728 consecutive patients, participated in the evaluation of a new videolaryngoscope [GlideScope (GS)]. Many operators had limited or no previous GS experience. Can J Anaesth. 2005 Feb;52(2):191-8.
Early clinical experience with a new video laryngoscope GS (GlideScope) Cooper RM, Pacey JA, Can J Anaesth. 2005 Feb;52(2):191-8 RESULTS: Excellent (C/L 1 or 2) laryngeal exposure was obtained in 99% GS: successful intubation in 96.3% of patients In all 133 patients in whom both GS and direct laryngoscopy (DL) were performed, GS resulted in a comparable or superior view. Among the 35 patients with C/L grade 3 or 4 views by DL, the view improved to a C/L 1 view in 24 and a C/L 2 view in 3 patients. CONCLUSIONS: GS laryngoscopy consistently yielded a comparable or superior glottic view compared with DL despite the limited or lack of prior experience with the device. Successful intubation was generally achieved even when DL was predicted to be moderately or extremely difficult
Anaesthesiol. 2010 Jan; 27(1) : 24-30. Serocki G, et al 120 adult patients with at least one predictor for a difficult airway were enrolled A comparison of conventional blade laryngoscopy with video-assisted blade laryngoscopy and the GlideScope. RESULTS: Both video laryngoscopes showed significantly better laryngoscopic view Laryngoscopic view C&L > or = III : 30% vs 11% (direct laryngoscopy and DCI laryngoscope; P < 0.001) Intubation failed in 4 (10%) Vs 1 case (2.5%) (DL vs VLS)
Video laryngoscopy in ankylosing spondylitis The use of the GlideScope for tracheal intubation in patients with ankylosing spondylitis (AS) METHODS: 20 AS patients were chosen to undergo tracheal intubation by the GlideScope and DL CONCLUSIONS: The GlideScope provided better laryngoscopic view than that of direct laryngoscopy. Most of the AS patients presenting with MCLS grade III or IV by direct laryngoscopy can be intubated successfully by the GlideScope on 17/20 occasions Br J Anaesth. 2006 Sep;97(3):419-22. Lai HY, et al
Pentax AWS Video laryngoscope in predicted difficult airways 293 patients with difficult airways. Two groups: 270 patients with difficult laryngoscopy and 23 predicted difficulty in intubation and mask ventilation RESULTS: In 256 patients in whom the grade was 3 or 4 with the Macintosh laryngoscope, the view with the Pentax-AWS was either grade 1 or 2 in 255 patients (99.6%; 95% confidence interval CI 97.8-100%). Tracheal intubation was successful with the Pentax- AWS in 268 of 270 patients (99.3%; 95% CI 97.4-100%) Anesthesiology. 2009 Apr;110(4):898-904: Asai T, et al
Pentax AWS Video laryngoscope in difficult airways CONCLUSION: The success rate of tracheal intubation using the Pentax-AWS was high in patients with difficult laryngoscopy with a Macintosh laryngoscope and in patients with predicted difficult intubation. Anesthesiology. 2009 Apr;110(4):898-904: Asai T, et al
Current evidence in favour of VLS VL devices improve laryngeal view as compared to DL in patients with suspected difficult intubation (DI) and simulated difficult airway scenarios. Sakles et al. A recent retrospective study of 822 emergent intubations by found ETI success rate with VL versus DL to be almost equivalent (75%vs 68%, (P=0.03) 1 st attempt success rate. At two or more difficult airway predictors (70% versus 56%,respectively) A similar result was found in the intensive care unit (ICU) setting by Ural et al., Aziz et al., demonstrated a high ETI success rate using GlideScope in primary airway management (98%; 1,712 of 1,755), in predicted DI (96%; 1,377 of 1,428), and rescue following failed DL (94%; 224 of 239).
Current evidence many or may not in favour of VLS Niforopoulou et al., concluded in their 2010 topical literature review that VL did not offer anything more than Macintosh in easy DL with C/L grades I or II and increases intubation time. However, in difficult airways with C/L grade III or IV it was proven to convert blind views into one under visual control and achieved the same or higher ETI success rate with equal or faster intubation time. Despite the lack of uniformity and need for further investigation, VL continues to gain popularity both inside and outside the operating room
First pass success of intubation? Despite a lack of clear evidence suggesting VL improves overall ETI success,[6,7,8,9] VL has quickly become a well-established tool in the armamentarium of the anesthesiologist as well as other healthcare providers (e.g., emergency department, intensive care unit, and prehospital settings) involved in airway management.[10,11]
First pass success Unplanned airway management, occurring in the ICU, operating room (OR), emergency department (ED), or elsewhere in the hospital, is a high-stakes event with the potential for dire consequences for the patient should intubation prove difficult or impossible and hypoxia ensue. Maximizing patient safety during these complex, high-risk procedures is paramount Several studies have shown a strong correlation between the number of intubation attempts and the rate of peri-intubation adverse events, such as hypoxia, esophageal intubation, bleeding, and need for surgical rescue Sakles JC, Chiu S, Mosier J, et al: The importance of first pass success when performing orotracheal intubation in the emergency department. Acad Emerg Med; 2013; 20: 71-78 Significantly higher rates of first-pass success (73% vs 40%) and fewer overall attempts with the GlideScope compared with DL..
Emergency Department intubation Trend Our recent multicenter study of more than 17,500 adult ED intubations showed that VL use is increasing, along with firstpass intubation success, over the last 10 years. This suggests that VL will likely overtake DL as the principal emergency intubation method in the near future. Brown CA, Bair AE, Pallin DJ, et al: Techniques, success, and adverse events of emergency department adult intubations. Ann Emerg Med 2014 Dec19
Comparison of Direct versus indirect laryngoscopy for intubation by prehospital providers: A systematic Review and Meta-analysis Brown, C. A., 3rd, A. E. Bair, D. J. Pallin, R. M. Walls, and Near Iii Investigators. "Techniques, Success, and Adverse Events of Emergency Department Adult Intubations." Ann Emerg Med 65, no. 4 (Apr 2015): 363-70 e1.
Take home message from literature VLS improve laryngoscopic view in potential difficult airway patients, both predicted and unpredicted Success of intubation is superior in predicted difficulty First pass success of intubation is high in nonanaesthetists /ED No marked benefit in laryngoscopic view in general population with experienced operators Still there is a gap between better laryngeal view and easy intubation Ability to bridge this gap is our challenge
VLS Limitations and complications Difficulty with inserting certain VL devices into the oral cavity Angulated blade of GlideScope GVL requires a greater tilt of the handle to enter the oropharynx. Despite an improved glottic view, ETT insertion may be problematic especially with angulated blade video laryngoscopes Use of a stylet and proper contouring of ETT is needed to facilitate passage through the vocal cords Upon passing the vocal cords, the ETT may abut against the anterior aspect of the subglottic trachea. Mainly designed for non pathological airway
Please note the differences Rule 1: experience with a standard Macintosh laryngoscope does not equate to skill with a Videolaryngoscope Rule 2: experience with one type of videolaryngoscope does not equate to skill with all videolaryngoscopes Rule 3: a good videolaryngoscopic view of the vocal cords does not guarantee easy intubation Rule 4: a bougie may not be the solution when there is difficulty Rule 5: a preformed ET tube is essential using any curved VLS blade
The future of Videolaryngoscopy (VL) VL has been the potential to enhance patient safety VL is part of a technological revolution in anaesthesia, but replace traditional laryngoscopy is controversial. However, the American Society of Anesthesiologists (ASA), DAS, CSA have already incorporated VL as an adjunct to Alternative Difficult Intubation Approaches in their practice guidelines for management of the difficult airway. VL need to be taught to the trainee (future) anaesthesiologists. Increasing interest from other healthcare providers who are potentially involved in airway management, like ITU, A&E, outreach airway care need to be considered
Conclusion Videolaryngoscopes have quickly gained popularity Their indirect view of the upper airway improves glottic visualization, including in suspected or encountered difficult intubation. More studies are needed to determine whether VL actually improves ETI success rates, intubation times, and firstattempt success rates; and thereby a potential replacement to traditional direct laryngoscopy. Advances in technology have heralded a wide array of models each with their own strengths, weaknesses, and optimal applications. The role of VL continues to evolve, need to be embraced
My vision Video technology has revolutionised medical and surgical practice in the recent past Video laryngoscopy would follow transforming airway management in anaesthetic practice It s only a matter of time Thank You
THANK YOU Dr Jayaram K Dasan FRCA King s College Hospital, King s Health Partner, London, UK Page 53