The era of video laryngoscopy has entered its second decade. Video Laryngoscopy: A Debate

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1 PRINTER-FRIENDLY VERSION AT ANESTHESIOLOGYNEWS.COM Video Laryngoscopy: A Debate 30 Laryngoscopic Skills Should Be Taught Using Video Devices 32 Video Laryngoscopy: Too Much, Too Soon! 33 Using the GlideScope in Awake Intubation and Assisted Fiber-optic Intubation 34 Video Laryngoscopy: Great Glottic View, but Does it Really Make a Difference Clinically In Routine Practice? The era of video laryngoscopy has entered its second decade. The introduction in 2001 of the Video Mac (Karl Storz) and GlideScope (Verathon Medical) devices, and the subsequent release of other video-enabled instruments, revolutionized the field of airway management. That much is beyond dispute. But revolutions are never tidy; ragged ends require trimming. In the pages that follow, airway experts face off on how much of an impact video laryngoscopes have made in the past decade where they have lived up to their billing and where they have yet to prove themselves. ANESTHESIOLOGY NEWS GUIDE TO AIRWAY MANAGEMENT

2 Laryngoscopic Skills Should Be Taught Using Video Devices M.B. KAPLAN, MD Associate Clinical Professor Department of Anesthesiology University of California Los Angeles Attending Anesthesiologist Cedars-Sinai Medical Center Los Angeles, California D.S. WARD, MD, PHD Professor and Chair Department of Anesthesiology University of Rochester Rochester, New York Drs. Kaplan and Ward have received unrestricted research support from Karl Storz USA. Learning a complex skill that involves visual and physical coordination has been described using a sigmoid-shaped curve. Such a learning curve for tracheal intubation using direct laryngoscopy (DL) would plot probability of success versus number of attempts, in other words experience. Initially, improvement progresses slowly until the practitioner gains an understanding of the basic components of intubation. This part of learning often can be improved with simulation practice and didactic instruction. The next part of the curve represents the rapid learning phase in which proficiency improves greatly with each additional attempt. The final plateau represents the attainment of a level of mastery, with the final success rate depending on the individual s skill and factors such as the difficulty of the intubation. In addition, although it usually is not thought of as a part of a learning curve, the rate of deterioration of the skill with disuse may be significant. Although this decline may be unimportant for anesthesiologists who perform intubations routinely, for other health care providers (such as emergency medicine and critical care physicians and paramedics) who perform intubations less regularly, retention of the learned skill is important. And, although the ultimate level of proficiency probably is more important than the rate of learning, the complication rate the number of chipped or broken teeth, failed intubations, and other undesirable outcomes during the learning process is not trivial. Only a few studies have attempted to analyze the learning curve for intubation using DL. Yet they clearly demonstrate that using a video system allows the novice to become successful with fewer practice intubations and with fewer complications during the learning process. For example, Mulcaster et al found a 90% probability of a learner performing a good laryngoscopic tracheal intubation after the trainee had performed 47±11.2 intubations. 1 During the training period of 456 intubations by 20 trainees, the complication rate was 23.7%; most of these were minor. When studying the learning rate for several anesthetic procedures, Konrad and colleagues similarly found that a 90% intubation success rate was achieved after a mean of 57 attempts. 2 Even after 80 intubations, however, 18% of residents in the study required assistance. This finding suggests that attaining proficiency in difficult intubation may require more training under supervision. What is not known is how proficiency in routine intubation translates to difficult intubation. How do the learning curves for routine versus difficult intubations differ? Howard-Quijano et al reported that 37 novices performed successful intubations in 69% of attempts 30 INDEPENDENTLY DEVELOPED BY MCMAHON PUBLISHING

3 with a Macintosh video laryngoscope system (Karl Storz) but succeeded only 55% of the time with conventional laryngoscopy (P=0.04). 3 Also significant was the reduction in esophageal intubations, from 17% to 3% (P<0.01), when using the video technique. Similarly, Nouruzi-Sedeh et al found that on their first 5 attempts, novice users of the GlideScope (Verathon Medical) had a success rate of 93%, compared with 51% with DL (P<0.01). 4 In a manikin study, Miki et al found that novices performing their first 10 intubations were successful 91.3% of the time using the Airway Scope (Pentax) but were successful 79.4% of the time when using a Macintosh laryngoscope (P<0.001). 5 The rate of esophageal intubations was zero for the video system and 13% with the conventional device. The instructor s ability to observe and correct the performance of a novice is essential to the learning process. Thus, there is considerable face validity in using a video laryngoscope that allows the instructor to guide the learner. It is the authors experience that novices often fail to recognize anatomical structures that are clear to the instructor. For example, they mistake the esophageal opening for the larynx when the laryngoscope is inserted too deeply or miss a folded-over epiglottis. A video system, particularly with a recorded playback option, permits accurate and meaningful instruction. In addition, it is our experience, corroborated by that of numerous colleagues, that stress on the instructor is dramatically decreased when using a video system to teach. Having said this, more evidence is needed to show that using a video laryngoscope for initial instruction reduces the complication rate and number of intubations required to reach proficiency and promotes a longer skill retention time and better transference of the skill to other non-video laryngoscopes. The growing number of video laryngoscopes available to clinicians speaks strongly for the acceptance of video technique as a significant advancement in the teaching and practice of airway management. Acknowledgment The authors wish to thank George Berci, MD, for his support in developing video laryngoscopy. References 1. Mulcaster JT, Mills J, Hung OR, et al. Laryngoscopic intubation: learning and performance. Anesthesiology. 2003;98(1): Konrad C, Schupfer G, Wietlisbach M, Gerber H. Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures? Anesth Analg. 1998;86(3): Howard-Quijano KJ, Huang YM, Matevosian R, Kaplan MB, Steadman RH. Video-assisted instruction improves the success rate for tracheal intubation by novices. Br J Anaesth. 2008;101(14): Nouruzi-Sedeh P, Schumann M, Groeben H. Laryngoscopy via Macintosh blade versus GlideScope: success rate and time for endotracheal intubation in untrained medical personnel. Anesthesiology. 2009;110(1): Miki T, Inagawa G, Kikuchi T, Koyama Y, Goto T. Evaluation of the Airway Scope, a new video laryngoscope, in tracheal intubation by naive operators: a manikin study. Acta Anaesthesiol Scand. 2007;51(10): ANESTHESIOLOGY NEWS GUIDE TO AIRWAY MANAGEMENT

4 Video Laryngoscopy: Too Much, Too Soon! CHRISTOPHER M. GRANDE, MD, MPH Anesthesiologist, Intensivist Executive Director International TraumaCare Baltimore, Maryland The author reports no relevant financial conflicts. As a founder of Project SAFE (Sedation and Airway For Everyone; I am confident that substantial advances in patient safety have been achieved through the rapid introduction and diffusion of video laryngoscopy (VL) technology. This is true not only within the specialty of anesthesiology, but also across related specialties, such as emergency medicine and critical care. Indeed, such advances are now beginning to trickle down to paraprofessionals. However, one also must recognize that perhaps there are some detractors. Currently, objective evidence is scant regarding potential detriments associated with teaching VL techniques not only to novices, but to individuals in active practice, as well. This detrimental effect arises when a reliance on VL for managing difficult airways happens too soon in the course of a novice s training, and when advanced practitioners rely too frequently on VL in their daily practice. Certainly, there are competing interests. One might argue that the risks for minor complications in patients (eg, chipped or broken teeth, and lacerations of the upper airway caused by trauma from direct laryngoscopy [DL] or other conventional methodologies) might be lessened by proceeding sooner or immediately to VL. This introduces the policy dilemma of exactly when is the appropriate time to introduce VL to newcomers as part of their repertoire of airway management techniques. In addition, there is the question of how frequently clinicians should employ DL and other conventional techniques in the ordinary course of patient care so as to preserve these skills, which are difficult to acquire and maintain. I am unaware of any specific policies that currently address this quandary, but one must reasonably assume that the natural tendency is to take the easy way out. Indeed, this also may prove safer for the patient in the short term. In the long run, however, skills will be lost or in the case of novices, never learned. Since the introduction of VL in the last decade, along with the accumulation of ever more clinical information, it is well accepted that no single technique works all the time. Thus, if one s competency is sacrificed by infrequently using conventional methods such as DL in difficult airway cases, these skills may deteriorate to the extent that one s competency becomes questionable. At a time when such skills are direly needed, this is a real dilemma. In my own practice, I initially manage the potentially challenging airway of any patient by using DL or another conventional technique; I have VL technology immediately available as a fallback. If it is not possible to initially secure the airway using conventional methods, or if in my judgment there is a clear risk for injury (no matter how minor) to the patient, I proceed immediately to a VL technique. Too often, however, I have observed clinicians forfeit opportunities to maintain competency with DL and compare the relative advantages and disadvantages of DL with VL, by a decision to proceed immediately to VL. 32 INDEPENDENTLY DEVELOPED BY MCMAHON PUBLISHING

5 Using the GlideScope in Awake Intubation And Assisted Fiber-optic Intubation D. JOHN DOYLE, MD, PHD Professor of Anesthesiology Cleveland Clinic Lerner College of Medicine of Case Western Reserve University Staff anesthesiologist Department of General Anesthesiology Cleveland Clinic Foundation Cleveland, Ohio The author reports no relevant financial conflicts. The GlideScope (Verathon Medical) became a go to airway device for unexpected difficult intubations soon after its introduction in Since that time, its use has expanded to include both awake intubation 2 and GlideScopeassisted fiber-optic intubation. 3 Using the GlideScope in awake intubation can be accomplished after the patient s airway has first been anesthetized (carefully and completely) with lidocaine spray or another preparation. Formal airway blocks generally are not needed. Using the GlideScope for awake intubations has the following advantages: It provides a good view of the glottis that can be used to administer additional topical anesthesia using a device such as the MADgic laryngotracheal mucosal atomizer (Wolfe Tory Medical, Inc./LMA North America). A clear view of the tracheal tube passing into the trachea adds a measure of safety. Individuals other than the operator are able to view the intubation. The intubation is easily recorded. There are fewer problems caused by blood and secretions compared with fiber-optic intubation. 2 GlideScope-assisted fiber-optic intubation has become another option for difficult airway management. This technique also has potential for teaching residents the proper technique for fiber-optic intubation. 3 Performed on the patient who is either awake or under general anesthesia depending on the clinical scenario, the technique starts with introducing the Glide-Scope, followed by the fiber-optic bronchoscope. In the teaching setting, the instructor is able to use the GlideScope to see the tip of the fiber-optic bronchoscope as controlled by the resident. (The GlideScope provides a macro view.) In this manner, the instructor can provide real-time guidance to supplement the micro view provided by the bronchoscope. When used for purely clinical purposes, the GlideScope can assist in a fiber-optic intubation by providing an alternative view of the airway; such a view can be helpful, for example, in the case of a bloody airway or severely distorted anatomy. 3 References 1. Cooper RM. Use of a new videolaryngoscope (GlideScope) in the management of a difficult airway. Can J Anesth. 2003;50(6): Doyle DJ. Awake intubation using the GlideScope video laryngoscope: initial experience in four cases. Can J Anesth. 2004;51(5): Doyle DJ. GlideScope-assisted fiberoptic intubation: a new airway teaching method. Anesthesiology. 2004;101(5):1252. ANESTHESIOLOGY NEWS GUIDE TO AIRWAY MANAGEMENT

6 Video Laryngoscopy: Great Glottic View, but Does It Really Make a Difference Clinically in Routine Practice? PAUL F. WHITE, PHD, MD Director of Clinical Research Department of Anesthesia Cedars-Sinai Medical Center Los Angeles, California Visiting Scientist Research Unit of Anesthesia and Intensive Care Rizzoli Orthopedic Institute, University of Bologna Bologna, Italy OFELIA LOANI ELVIR-LAZO, MD Clinical Research Coordinator Department of Anesthesia Cedars-Sinai Medical Center Los Angeles, California The authors report no relevant financial conflicts. Despite the development of new video devices for airway management, direct laryngoscopy (DL) remains the gold standard for tracheal intubation in children and adults. Video laryngoscopy (VL) clearly improves glottic visualization by providing a wider visual field that allows the practitioner to more rapidly identify anatomic structures. 1 The commonly used Cormack-Lehane (C-L) system (to grade the glottic view during laryngoscopy), 2 and the percentage of glottic opening (POGO) score (used to grade glottic view as a percentage of the entire glottic opening visualized during laryngoscopy), 3 are both surrogate end points; they may or may not be correlated with clinically meaningful end points. It is well known that a good laryngeal view does not guarantee successful tracheal tube insertion. Therefore, the clinically important question is whether the use of VL leads to higher success rates for intubation and a shorter time to secure the airway when used by trained anesthesia providers both in routine tracheal intubation and so-called difficult airways related to patient anatomy. The use of VL in children provided a better view of the larynx than DL, but at the expense of a longer time to achieve successful tracheal intubation. 4,5 Vlatten and colleagues 4 recently studied 53 patients and compared the Video-Miller device (a standard pediatric Miller blade with camera attached) to either a Miller 1 or a Macintosh 2 blade. In addition to being an underpowered study (because of the relatively small group sizes), the practitioners had varying degrees of experience using the Video-Miller equipment. In a 2008 publication by Robitaille et al, 6 the investigators compared DL with GlideScope VL (Verathon Medical) using cinefluoroscopic images of cervical spine movement during the tracheal intubation of patients. The patients had no cervical spine pathologies, and received general anesthesia with neuromuscular blockade and manual inline stabilization. The authors concluded that VL with a GlideScope provided better glottis visualization, but did not significantly decrease movement of the nonpathologic C-spine when compared with DL. In another recent study, van Zundert et al 7 randomly assigned healthy adults undergoing tracheal intubation for elective surgery to receive airway management with the GlideScope Ranger (Verathon 34 INDEPENDENTLY DEVELOPED BY MCMAHON PUBLISHING

7 Medical), Video-MAC (V-MAC; Karl Storz Endoscopy), or McGrath Series 5 (Aircraft Medical Ltd) video devices. The tracheas of all patients were successfully intubated. As expected, all 3 video systems provided equal or better views of the glottis (as assessed by C-L, mean grade) than did traditional Macintosh laryngoscopy; this included a larger viewing angle of the glottic entrance. The average intubation time was 34±20 seconds for the GlideScope Ranger, 18±12 seconds for the V-MAC, and 38±23 seconds for the McGrath. Intubation with the V-MAC was significantly faster than with the other 2 devices tested. The V-MAC also required fewer additional tools, resulting in a higher success rate of first-pass intubation. A stylet had to be used in 7% of the patients in the V-MAC group compared with about 50% of the patients when the GlideScope Ranger or McGrath devices were used. Unfortunately, the authors did not report the comparative intubation times or the need for a stylet in the DL group. Maassen et al 8 compared the GlideScope, V-MAC, and McGrath devices, and concluded that the scope with the Macintosh blade (V-MAC) was better with regard to overall satisfaction score, intubation time, number of intubation attempts, and need for extra adjuncts than the GlideScope and McGrath devices. The investigators also described the usefulness of the video-assisted V-MAC laryngoscope in an obese patient with anticipated difficult airway to reduce the risk for dental damage during the intubation procedure. 9 Recently, Cavus et al 10 described 3 patients (C-L grades III, IV, and V) in whom unexpected difficulty was encountered with DL using a conventional Macintosh laryngoscope, and these patients were successfully intubated on the first attempt using the C-MAC video laryngoscope (Karl Storz Endoscopy). In addition, Meininger et al 11 reported that the C-MAC device significantly enhanced laryngeal view compared with DL with a Macintosh laryngoscope blade. However, when indirect laryngoscopy is performed with the C-MAC, these authors suggested that it can present an unfavorable deviation of optical and anatomic axes. Nouruzi-Sedeh and colleagues 12 compared success rates and endotracheal intubation times when untrained medical personnel performed laryngoscopy with the Macintosh blade or the GlideScope. The investigators reported an overall success rate of 93% for the GlideScope technique and 51% for DL (P<0.01). Time to intubation was 89±35 seconds with DL and 63±30 seconds with the GlideScope (P<0.01). Untrained (novice) practitioners successfully intubated more than 90% of the patients within 120 seconds after the first attempt with VL, compared with 51% of the patients with DL. Walker et al 13 concluded that, in the hands of inexperienced anesthetists, the McGrath laryngoscope offered no advantage in uncomplicated tracheal intubations because the intubation time was longer. In a recent review article, Aziz et al 14 stated that the GlideScope has been shown to be a useful tool to improve laryngeal view; however, intubation with the GlideScope is not always successful despite the capability of visualizing the glottis. Another concern relates to reports of complications associated with styletted tracheal tubes used with VL. Cooper 15 published a report of injury related to the use of the GlideScope, namely perforation of the palatopharyngeal arch in 2 patients. Vincent et al 16 reported a case in which a video laryngoscope was used to facilitate endotracheal intubation in a patient with a large exophytic mass involving the right supraglottis; the soft palate was perforated by the styletted endotracheal tube. Hsu et al 17 also reported an injury of the right palatoglossal arch caused by tracheal intubation with the GlideScope. Potential complications involving the oropharyngeal area always should be kept in mind when using video devices for routine tracheal intubation, particularly when styletted tracheal tubes are used In conclusion, video laryngoscopes are valuable adjuvants for airway management, in addition to being helpful for teaching young physicians about airway anatomy and proper techniques for tracheal intubation. Although VL clearly improves the view of the glottis, scientific evidence demonstrating improvements in the process of tracheal intubation in patients with normal and abnormal airways is lacking for the devices currently on the market. References 1. Levin R, Kissoon N, Froese N. Fibreoptic and videoscopic indirect intubation techniques for intubation in children. Pediatr Emerg Care. 2009;25(7): Cormack RS, Lehane J. Difficult tracheal intubation in obstetrics. Anaesthesia. 1984;39(11): Ochroch EA, Hollander JE, Kush S, Shofer FS, Levitan RM. Assessment of laryngeal view: percentage of glottic opening score vs Cormack and Lehane grading. Can J Anesth. 1999;46(10): Vlatten A, Aucoin S, Litz S, Macmanus B, Soder C. A comparison of the Storz video laryngoscope and standard direct laryngoscopy for intubation in the pediatric airway: a randomized clinical trial. Paediatr Anaesth. 2009;19(11): Macnair D, Baraclough D, Wilson G, Bloch M, Engelhardt T. Pediatric airway management: comparing the Berci-Kaplan Video Laryngoscope with direct laryngoscopy. Paediatr Anaesth. 2009; 19(6): Robitaille A, Williams SR, Tremblay MH, Guilbert F, Thériault M, Drolet P. Cervical spine motion during tracheal intubation with manual in-line stabilization: direct laryngoscopy versus Glide- Scope videolaryngoscopy. Anesth Analg. 2008;106(3): van Zundert A, Maassen R, Lee R, et al. A Macintosh laryngoscope blade for videolaryngoscopy reduces stylet use in patients with normal airways. Anesth Analg. 2009;109(3): Maassen R, Lee R, Hermans B, Marcus M, van Zundert A. A comparison of three videolaryngoscopes: the Macintosh laryngoscope blade reduces, but does not replace, routine stylet use for intubation in morbidly obese patients. Anesth Analg. 2009; 109(5): ANESTHESIOLOGY NEWS GUIDE TO AIRWAY MANAGEMENT

8 9. Maassen R, Lee R, van Zundert A, Cooper R. The videolaryngoscope is less traumatic than the classic laryngoscope for a difficult airway in an obese patient. J Anesth. 2009;23(3): Cavus E, Kieckhaefer J, Doerges V, Moeller T, Thee C, Wagner K. The C-MAC videolaryngoscope: first experiences with a new device for videolaryngoscopy-guided intubation. Anesth Analg. 2010; 110(2): Meininger D, Strouhal U, Weber CF, et al. Direct laryngoscopy or C-MAC video laryngoscopy? Routine tracheal intubation in patients undergoing ENT surgery [in German]. Anaesthesist. 2010; 59(9): Nouruzi-Sedeh P, Schumann M, Groeben H. Laryngoscopy via Macintosh blade versus GlideScope: success rate and time for endotracheal intubation in untrained medical personnel. Anesthesiology. 2009;110(1): Walker L, Brampton W, Halai M, et al. Randomized controlled trial of intubation with the McGrath Series 5 videolaryngoscope by inexperienced anaesthetists. Br J Anaesth. 2009;103(3): difficult airway management: an analysis of 2,004 GlideScope intubations, complications, and failures from two institutions. Anesthesiology. 2011; 114(1): Cooper RM. Complications associated with the use of the Glide- Scope videolaryngoscope. Can J Anesth. 2007;54(1): Vincent RD Jr, Wimberly MP, Brockwell RC, Magnuson JS. Soft palate perforation during orotracheal intubation facilitated by the GlideScope videolaryngoscope. J Clin Anesth. 2007;19(8): Hsu WT, Hsu SC, Lee YL, Huang JS, Chen CL. Penetrating injury of the soft palate during GlideScope intubation. Anesth Analg. 2007;104(6): Hirabayashi Y. Pharyngeal injury related to GlideScope videolaryngoscope. Otolaryngol Head Neck Surg. 2007;137(1): Malik AM, Frogel JK. Anterior tonsillar pillar perforation during Glide Scope video laryngoscopy. Anesth Analg. 2007; 104(6): Aziz MF, Healy D, Kheterpal S, Fu RF, Dillman D, Brambrink AM. Routine clinical practice effectiveness of the GlideScope in 20. Choo MK, Yeo VS, See JJ. Another complication associated with videolaryngoscopy. Can J Anesth. 2007;54(4): INDEPENDENTLY DEVELOPED BY MCMAHON PUBLISHING