Whats New in Critical Illness and Injury Science? Airway management: Is this as good as it gets? The origins of laryngoscopy can be traced back to over 150 years when Manuel Garcia, a Spanish voice teacher, provided detailed descriptions of his own larynx. He visualized it using a dental mirror and a second, handheld mirror, to reflect sunlight. [1] Not long after, Johann Czermak, a professor of physiology, improved upon Garcia’s mirrors and the techniques of Ludwig Türk, a professor of laryngology in Vienna, by using an artificial light source and a light concentrating concave head mirror to visualize the larynx in patients.[2] As a result, he is widely credited as the inventor of laryngoscopy. In contrast to these techniques, best described as indirect laryngoscopy, modern direct laryngoscopy as we know it today, lagged behind by decades. Despite purposeful steps toward the development of the direct laryngoscope in the mid to late 19th century, examination was only possible in patients with unusually favorable anatomy. Lack of exposure and appropriate lighting severely limited its widespread application. Coincident with the advent and development of the incandescent light bulb in the late 19th century, Chevalier Jackson placed small light bulbs directly into the laryngoscope. [3] In 1913, the same year the Jackson laryngoscope blade was introduced; Henry H. Janeway, an anesthesiologist at Bellevue Hospital in New York City reported the use of a self‑designed laryngoscope specifically to facilitate direct tracheal insufflation of volatile anesthetics and intubation. In addition, and unique until this point in time, he incorporated batteries within the handle. Also found were a central notch in the blade for maintaining the tracheal tube in the midline of oropharynx during intubation, and a slight curve to the distal tip of the blade to help guide the tube through the glottis.[4] Thus, Janeway and his design were paramount in popularizing direct tracheal intubation in the practice of anesthesiology. Of course, this technique is still in use today, performed largely with the two laryngoscope blades developed by Drs. Robert A. Miller and Robert Reynolds Macintosh in 1941 and 1943, respectively.[5,6] Access this article online Website: www.ijciis.org DOI: 10.4103/2229-5151.128004

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Dr. Shigeto Ikeda is credited with developing the flexible fiberscope in 1966. [7] Although initially considered for use only if all traditional methods failed prior to performing a surgical airway, reports of its use as a first line intubation technique were first reported in the English language in the early 1970s. Conyers contributed a case report of its use for nasotracheal intubation in 1972 and Mulder reported 14 patients with head and neck trauma that were successfully intubated with the technique in 1975. [8,9] For the next 15 years, the standard airway management skill set would consist of supraglottic ventilation via facemask with or without the use of oro‑ and nasopharyngeal airway adjuncts and/or tracheal intubation by direct laryngoscopy or flexible fiberoptic endoscopy. In late 1987, the laryngeal mask airway (LMA) was first introduced for clinical use in the UK. It was the culmination of 6 years of work by Dr. Archie Brain. Within the first 3 years of introduction, it had been used over 2 million times. By 1993, the LMA had been approved for use in Australia, New Zealand, Asia, and the United States. By 1995, the LMA had been distributed and used in over 80 countries and in over 100 million patients, largely replacing the provision of general anesthesia by facemask and as the initial device of choice for airway rescue when difficult ventilation arose.[10] It is not surprising that some have considered the introduction of the LMA to be one of the greatest developments in anesthesia that occurred during the second half of the 20th century. Fast forward to the beginning of the 21st century when the Glidescope TM (Verathon, Inc., Bothell, WA, USA), in essence a hyper‑curved rigid laryngoscope blade with the light source and video capabilities of the fiberoptic endoscope incorporated into the blade and handle then projected on a screen tethered to the handle by a cord, was introduced as the first commercially available video laryngoscope. It was now possible to gain good‑to‑excellent laryngeal exposure during intubation attempts in 90-95% of patients, a significant improvement over conventional direct laryngoscopy.[11] The introduction of the GlidescopeTM defined a new category of airway management tools, video laryngoscopy, just as the laryngeal mask had done for supraglottic airway devices some 15 years earlier. Surely, with all this technology, airway management difficulty and the related morbidity would go the way of the Dodo (Raphus cucullatus, the

International Journal of Critical Illness and Injury Science | Vol. 4 | Issue 1 | Jan-Mar 2014


Joffe: Airway management

extinct flightless bird that was endemic to the island of Mauritius, east of Madagascar in the Indian Ocean), right? According to the American Society of Anesthesiologists Closed Claims Project (ASACCP), respiratory events (inadequate ventilation, esophageal intubation, difficult intubation) still accounted for >50% of all claims leading to death or permanent brain damage in the 1980s and 1990s.[12‑14] And while the number of claims related to the peri‑induction period declined substantially from 1970 to 1999, the number of airway related events at extubation or during recovery remained stable at 20%. Furthermore, airway‑related claims from outside the operating room were universally catastrophic with 100% mortality reported. It is important to recognize that the ASACCP represents a small number of cases (as few as 5% of critical events), is reviewed up to a decade after the fact, is subject to a number of biases inherent to all such retrospective reviews, and has no denominator.[15] Nonetheless, those who doubt the validity of the ASACCP reports based on their limitations are directed to the results of the Fourth National Audit Project of the Royal College of Anesthetists and Difficult Airway Society (NAP4).[15,16] This was a voluntary prospective registry of major airway management related complications during a 12‑month period from 2008-2009. It included all 309 National Health Service hospitals among the four countries in the United Kingdom, and reported an estimated denominator. The reported event rate was as low as 1 per 22,000 general anesthetics and death in 1 per 180,000. Event rates were 2-4 times higher for tracheal tubes than supraglottic airways. Pulmonary aspiration of gastric contents was the most common cause of death or brain damage associated with difficult intubation. Notably, the causal and contributory factors were adjudicated to be judgment and education/training related in 62 and 47% of cases, respectively. Additionally, the quality of airway management was judged to be poor in over one‑third of cases. Nearly 20 years ago, Benumof said, “the most compelling educational effort for the anesthesia community should be to reduce the frequency and severity of complications related to managing the airway.”[15] Despite the incorporation of supraglottic devices and newer optical and video devices into airway management algorithms for routine anesthetic practice, this is no less true today. Borrowing from Dr. Tim Cook, the lead author of the NAP4 investigation: Never fail to be prepared for failure, do what you can do but not what you cannot, do not intubate when it is not indicated and do intubate when it is, and if it is not working stop and do something different.[15] Anesthesiology, a specialty which prides itself on being strong advocates for patient safety, must never accept that this is “as good as it gets”


just because the occurrence of catastrophic events are rare, particularly if they are avoidable. In this issue of the International Journal of Critical Illness and Injury Science appear a number of expert reviews on adult and pediatric airway management, which encompass a broad range of topics. Taken together, the articles should serve as a succinct, comprehensive, and up‑to‑date airway management reference. Aaron M Joffe

Department of Anesthesiology and Pain Medicine, University of Washington, Harborview Medical Center, Seattle, Washington, USA Address for correspondence: Dr. Aaron M Joffe, Department of Anesthesiology and Pain Medicine, University of Washington, Harborview Medical Center, 325 Ninth Ave, Box 359724, Seattle 98104, Washington, USA. E-mail: [email protected]

REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

Jahn A, Blitzer A. A short history of laryngoscopy. Logoped Phoniatr Vocol 1996;21:181‑5. Czermak JN. Der Kehlkopfspiegel, und seine Verwerthung für Physiologie und Medizin. Leipzig: Verl W Engelmann; 1860. Zeitels  SM. Chevalier Jackson’s contributions to direct laryngoscopy. J Voice 1998;12:1‑6. Janeway HH. Intra‑tracheal anesthesia from the standpoint of the nose, throat and oral surgeon with a description of a new instrument for catheterizing the trachea. Laryngoscope 1913;23:1082‑90. Miller RA. A new laryngoscope. Anesthesiology 1941;2:317‑20. Macintosh RR. A new laryngoscope. Lancet 1943;1:205. Ikeda S, Tsuboi E, Ono R. Flexible bronchfiberscope. Jpn J Clin Oncol 1971;1;55‑65. Conyers AB, Wallace DH, Mulder DS. Use of the fiber optic bronchoscope for nasotracheal intubation: Case report. Can Anaesth Soc J 1972;19:654‑6. Mulder  DS, Wallace  DH, Woolhouse  FM. The use of the fiberoptic bronchoscope to facilitate endotracheal intubation following head and neck trauma. J Trauma 1975;15:638‑40. Brimacombe  JR. Laryngeal Mask Anesthesia: Principles and Practice. 2nd ed. Philadelphia: Saunders; 2005. p. 23‑6. Cooper RM, Pacey JA, Bishop MJ, McCluskey SA. Early clinical experience with a new videolaryngoscope (GlideScope) in 728 patients. Can J Anaesth 2005;52:191‑8. Caplan RA, Posner KL, Ward RJ, Cheney FW. Adverse respiratory events in anesthesia: A closed claims analysis. Anesthesiology 1990;72:828‑33. Domino KB, Posner KL, Caplan RA, Cheney FW. Airway injury during anesthesia: A closed claims analysis. Anesthesiology 1999;91:1703‑11. Peterson GN, Domino KB, Caplan RA, Posner KL, Lee LA, Cheney FW. Management of the difficult airway: A  closed claims analysis. Anesthesiology 2005;103:33‑9. Cook TM, MacDougall‑Davis SR. Complications and failure of airway management. Br J Anaesth 2012;109 Suppl 1:i68‑85. Cook  TM, Woodall  N, Frerk  C. Fourth National Audit Project. Major complications of airway management in the UK: Results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part  1: Anaesthesia. Br J Anaesth 2011;106:617‑31.

Cite this article as: Joffe AM. Whats New in Critical Illness and Injury Science? Airway management: Is this as good as it gets?. Int J Crit Illn Inj Sci 2014;4:1-2. Source of Support: Nil, Conflict of Interest: No.

International Journal of Critical Illness and Injury Science | Vol. 4 | Issue 1 | Jan-Mar 2014

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