Saranya devi SPECIAL ARTICLES ALN Practice Guidelines Practice Guidelines for Management of the Difficult Airway Practice Guidelines An Updated Report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway 2 RACTICE Guidelines are systematically developed • What other guideline statements are available on this topic? recommendations that assist the practitioner and P ° These Practice Guidelines update the “Practice Guidelines 10.1097/ALN.0b013e31827773b2 patient in making decisions about health care. These recom- for Management of the Difficult Airway,” adopted by the mendations may be adopted, modified, or rejected accord- American Society of Anesthesiologists in 2002 and pub- ing to clinical needs and constraints and are not intended lished in 2003* • Why was this Guideline developed? February to replace local institutional policies. In addition, Practice ° In October 2011, the Committee on Standards and Prac- Guidelines developed by the American Society of Anesthe- tice Parameters elected to collect new evidence to deter- siologists (ASA) are not intended as standards or absolute mine whether recommendations in the existing Practice 2013 requirements, and their use cannot guarantee any specific Guideline were supported by current evidence outcome. Practice Guidelines are subject to revision as war- • How does this statement differ from existing Guidelines? ° New evidence presented includes an updated evaluation of ranted by the evolution of medical knowledge, technology, scientific literature and findings from surveys of experts and 20 and practice. They provide basic recommendations that are randomly selected American Society of Anesthesiologists supported by a synthesis and analysis of the current litera- members. The new findings did not necessitate a change in recommendations ture, expert and practitioner opinion, open-forum commen- • Why does this statement differ from existing Guidelines? tary, and clinical feasibility data. ° The American Society of Anesthesiologists Guidelines differ This document updates the “Practice Guidelines for from the existing Guidelines because it provides updated Management of the Difficult Airway: An Updated Report by evidence obtained from recent scientific literature and find- ings from new surveys of expert consultants and randomly selected American Society of Anesthesiologists members Updated by the Committee on Standards and Practice Param- eters: Jeffrey L. Apfelbaum, M.D. (Chair), Chicago, Illinois; Carin A. the Task Force on Difficult Airway Management,” adopted Hagberg, M.D., Houston, Texas; and selected members of the Task Force on Management of the Difficult Airway: Robert A. Caplan, by the ASA in 2002 and published in 2003.* M.D. (Chair), Seattle, Washington; Casey D. Blitt, M.D., Coronado, California; Richard T. Connis, Ph.D., Woodinville, Washington; and David G. Nickinovich, Ph.D., Bellevue, Washington. The previous Methodology update was developed by the American Society of Anesthesiolo- A. Definition of Difficult Airway gists Task Force on Difficult Airway Management: Robert A. Caplan, M.D. (Chair), Seattle, Washington; Jonathan L. Benumof, M.D., San A standard definition of the difficult airway cannot be identi- Diego, California; Frederic A. Berry, M.D., Charlottesville, Virginia; fied in the available literature. For these Practice Guidelines, Casey D. Blitt, M.D., Tucson, Arizona; Robert H. Bode, M.D., Bos- a difficult airway is defined as the clinical situation in which a ton, Massachusetts; Frederick W. Cheney, M.D., Seattle, Washington; Richard T. Connis, Ph.D., Woodinville, Washington; Orin F. Guidry, conventionally trained anesthesiologist experiences difficulty M.D., Jackson, Mississippi; David G. Nickinovich, Ph.D., Bellevue, with facemask ventilation of the upper airway, difficulty with Washington; and Andranik Ovassapian, M.D., Chicago, Illinois. tracheal intubation, or both. The difficult airway represents Received from American Society of Anesthesiologists, Park a complex interaction between patient factors, the clinical Ridge, Illinois. Submitted for publication October 18, 2012. Accepted for publication October 18, 2012. Supported by the American Soci- setting, and the skills of the practitioner. Analysis of this ety of Anesthesiologists and developed under the direction of the interaction requires precise collection and communication Committee on Standards and Practice Parameters, Jeffrey L. Apfel- of data. The Task Force urges clinicians and investigators to baum, M.D. (Chair). Approved by the ASA House of Delegates on October 17, 2012. A complete bibliography used to develop these use explicit descriptions of the difficult airway. Descriptions updated Guidelines, arranged alphabetically by author, is available that can be categorized or expressed as numerical values are as Supplemental Digital Content 1, http://links.lww.com/ALN/A902. particularly desirable, because this type of information lends Address correspondence to the American Society of Anesthe- itself to aggregate analysis and cross-study comparisons. siologists: 520 N. Northwest Highway, Park Ridge, Illinois 60068– 2573. These Practice Guidelines, and all ASA Practice Parameters, Suggested descriptions include, but are not limited to: may be obtained at no cost through the Journal Web site, www. anesthesiology.org. Supplemental digital content is available for this article. Direct *American Society of Anesthesiologists: Practice guidelines for URL citations appear in the printed text and are available in management of the difficult airway: An updated report. NESTHESIOLOGYA both the HTML and PDF versions of this article. Links to the 2003; 98:1269–1277. digital files are provided in the HTML text of this article on the Copyright © 2013, the American Society of Anesthesiologists, Inc. Lippincott Journal’s Web site (www.anesthesiology.org). Williams & Wilkins. Anesthesiology 2013; 118:XX–XX Anesthesiology, V 118 • No 2 1 February 2013 Copyright © by the American Society of Anesthesiologists.<zdoi;10.1097/ALN.0b013e31827773b2> Unauthorized reproduction of this article is prohibited. Practice Guidelines 1. Difficult facemask or supraglottic airway (SGA) ven- and airway management delivered in anesthetizing locations tilation (e.g., laryngeal mask airway [LMA], intubat- and is intended for all patients of all ages. ing LMA [ILMA], laryngeal tube): It is not possible for the anesthesiologist to provide adequate ventilation E. Task Force Members and Consultants because of one or more of the following problems: The original Guidelines and the first update were developed inadequate mask or SGA seal, excessive gas leak, or by an ASA-appointed Task Force of ten members, consisting excessive resistance to the ingress or egress of gas. Signs of Anesthesiologists in private and academic practices from of inadequate ventilation include (but are not limited various geographic areas of the United States and two con- to) absent or inadequate chest movement, absent or sulting methodologists from the ASA Committee on Stan- inadequate breath sounds, auscultatory signs of severe dards and Practice Parameters. obstruction, cyanosis, gastric air entry or dilatation, The original Guidelines and the first update in 2002 were developed by means of a seven-step process. First, the Task decreasing or inadequate oxygen saturation (SpO2), absent or inadequate exhaled carbon dioxide, absent or Force reached consensus on the criteria for evidence. Second, inadequate spirometric measures of exhaled gas flow, original published research studies from peer-reviewed jour- and hemodynamic changes associated with hypox- nals relevant to difficult airway management were reviewed emia or hypercarbia (e.g., hypertension, tachycardia, and evaluated. Third, expert consultants were asked to: (1) arrhythmia). participate in opinion surveys on the effectiveness of vari- 2. Difficult SGA placement: SGA placement requires mul- ous difficult airway management recommendations and (2) tiple attempts, in the presence or absence of tracheal review and comment on a draft of the Guidelines. Fourth, pathology. opinions about the Guideline recommendations were solic- 3. Difficult laryngoscopy: It is not possible to visualize any ited from a sample of active members of the ASA. Fifth, portion of the vocal cords after multiple attempts at opinion-based information obtained during open forums conventional laryngoscopy. for the original Guidelines,† and for the previous updated 4. Difficult tracheal intubation: Tracheal intubation Guidelines,‡ was evaluated. Sixth, the consultants were requires multiple attempts, in the presence or absence surveyed to assess their opinions on the feasibility of imple- of tracheal pathology. menting the updated Guidelines. Seventh, all available infor- 5. Failed intubation: Placement of the endotracheal tube mation was used to build consensus to finalize the updated fails after multiple attempts. Guidelines. In 2011, the ASA Committee on Standards and Practice B. Purposes of the Guidelines for Difficult Airway Parameters requested that the updated Guidelines published Management in 2002 be re-evaluated. This update consists of an evalu- The purpose of these Guidelines is to facilitate the manage- ation of literature published since completion of the first ment of the difficult airway and to reduce the likelihood of update, and an evaluation of new survey findings of expert adverse outcomes. The principal adverse outcomes associ- consultants and ASA members. A summary of recommenda-