Creative Approaches to the Difficult Airway

Educational Objectives

The goal of this program is to improve management of the difficult airway. After hearing and assimilating this program, the clinician will be better able to:

1. Use validated techniques to predict difficult airways.
2. Implement novel techniques for difficult airway management.

Summary

Difficult airway: traditionally, implies an anatomically difficult airway, with, eg, difficulty intubating, masking, placing a supraglottic airway, potential difficulty establishing front-of-neck access (FONA); physiologically difficult airway — may not be anatomically difficult, but the patient is severely hypoxic and at high risk for respiratory arrest or a severe hypoxic event, hypotension, or cardiac arrest; situationally difficult airway — includes difficulty because of time pressure, poor access to the patient, or absence of the correct equipment or experienced personnel; difficult lower airway — caused by subglottic stenosis or other issues distal to the larynx

Predicting difficult airways: current predictive tools are of limited accuracy (lack specificity and sensitivity); some of the most predictive tests are not routinely used, eg, the upper lip bite test (easy to perform; if the patient is unable to bite the upper lip, risk for difficult airway is considerably elevated); “MACOCHA” score — ie, Malampatti score 3 or 4, obstructive sleep apnea, cervical-spine movement limited, mouth opening <3 cm, coma, hypoxemia, and non-anesthetist intubator; used to assess the difficulty of intubating a patient in the intensive care unit; incorporates some aspects of a physiologically difficult airway (eg, hypoxia, hypotension); tumor, radiation, and surgery (TRS) score — a mnemonic for issues that affect the upper airway; other predictive factors — displaced tracheostomy; obesity (even if intubation is not difficult, may cause difficulty with masking, rapid desaturation, or difficult placement of a surgical airway; associated with elevated risk for aspiration)

INTUBE trial: a large, multicenter, multinational study of outcomes of critically ill patients who required emergency intubation; reported peri-intubation adverse events include significant hypotension (systolic blood pressure <65 mm Hg or <90 mm Hg for 30 min, or need for vasopressors), significant hypoxia, cardiac arrest (3%), difficult airway (4.7%), and esophageal intubation (5.6%)

Factors in poor management of a difficult airway: multiple intubation attempts using the same technique is likely most significant; lack of good teamwork also contributes; in some cases, unpredictable events occur

Managing difficult airways during the COVID-19 pandemic: the most successful strategies were largely nontechnical, eg, preparation, anticipation of problems, team coordination

Novel techniques for difficult airways: techniques include multimodal airway management, bougie-first intubation, direct laryngoscopy, apneic oxygenation, nasal ventilation, and FONA; Driver et al (2018) — 300 patients were randomized to standard direct laryngoscopy and intubation (using a tube and stylet) vs the bougie-first technique; the first-attempt success rate was much higher in the bougie-first group; time to intubation was similar in the 2 groups; the difference in first-attempt success rate was more significant in patients who had ≥1 risk factor for difficult airway; video laryngoscopy — widespread adoption may be causing erosion of direct laryngoscopy skills; despite providing a better view of the airway, inserting the tube in the airway still may be difficult; multimodal airway management — a direct or video laryngoscope is used as a retractor and a flexible bronchoscope as a stylet; a useful technique if oxygenation and ventilation are possible; also can be achieved using a laryngeal mask airway; anterior commissure laryngoscope — has been successfully used by otolaryngologic surgeons after failure of intubation with video laryngoscopy; advantageous for a patient with, eg, a small mouth opening (because of the lower profile), an obstructive mass (can be pushed aside), blood, vomit or other fluid in the airway (can be suctioned through the device)

Apneic oxygenation: increases the time available to achieve intubation; desaturation occurs more slowly while the nasal cannula is in place; transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) — heated high flow; generates oxygen flows of 60 to 70 L/min and can be set to 100%; high flow “washes out” CO₂; can be considered when a difficult airway is encountered in a patient with healthy lungs

Other techniques: nasal ventilation — the adaptor from an endotracheal tube is attached to a nasal trumpet, which is placed in the nose; allows oxygenation via spontaneous breathing, with monitoring of end-tidal CO₂; alternatively, the other nostril and the mouth can be kept closed while bag-valve-mask ventilation is performed; FONA — an observational case series showed a high failure rate (≈60%) with use of a needle and wire to establish a cricothyrotomy; the United Kingdom Difficult Airway Society advocates using the scalpel-bougie-tube technique

Nontechnical strategies for a difficult airway: emergency or difficult airway management is analogous to a code, in that it is a time-sensitive, high stakes situation; success depends on having a team of experts with active leadership, good communication, and training; a dedicated difficult airway response team is recommended by the Joint Commission; the speaker’s institution uses an airway timeout, during which all alternative plans and anticipated difficulties are discussed and other preparations are made (ie, “predict, plan, prepare, preoxygenate, position”); checklists — often long and may be inefficient for an emergency airway situation; “pit crew” model — all team members have a designated position and assigned responsibilities, with oversight by a leader

Additional terminology: dual setup — preparations are made simultaneously for nonsurgical and surgical intubation, in case the latter is needed; delayed-sequence intubation — use of a small dose of, eg, ketamine, to calm a noncooperative patient and facilitate preoxygenation and intubation

Airway vortex: an alternative to the American Society of Anesthesiologists difficult airway guideline, which is complicated and not easily used in an emergency; the concept includes 4 interventions, ie, mask, intubate, place a supraglottic airway, and place a surgical airway, with a maximum of 3 attempts at each; easy to memorize

Readings

Abdelmalak BB, Doyle DJ. Recent trends in airway management. F1000Res. 2020;9:F1000 Faculty Rev-355. Published 2020 May 13. doi:10.12688/f1000research.21914.1; Apfelbaum JL, Hagberg CA, Connis RT, et al. 2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway. Anesthesiology. 2022;136(1):31-81. doi:10.1097/ALN.0000000000004002; De Jong A, Molinari N, Terzi N, et al. Early identification of patients at risk for difficult intubation in the intensive care unit: development and validation of the MACOCHA score in a multicenter cohort study. Am J Respir Crit Care Med. 2013;187(8):832-839. doi:10.1164/rccm.201210-1851OC; Driver BE, Prekker ME, Klein LR, et al. Effect of use of a bougie vs endotracheal tube and stylet on first-attempt intubation success among patients with difficult airways undergoing emergency intubation: a randomized clinical trial. JAMA. 2018;319(21):2179-2189. doi:10.1001/jama.2018.6496; Faramarzi E, Soleimanpour H, Khan ZH, et al. Upper lip bite test for prediction of difficult airway: A systematic review. Pak J Med Sci. 2018;34(4):1019-1023. doi:10.12669/pjms.344.15364; Lenhardt R, Burkhart MT, Brock GN, Kanchi-Kandadai S, Sharma R, Akça O. Is video laryngoscope-assisted flexible tracheoscope intubation feasible for patients with predicted difficult airway? A prospective, randomized clinical trial [published correction appears in Anesth Analg. 2015 Feb;120(2):495]. Anesth Analg. 2014;118(6):1259-1265. doi:10.1213/ANE.0000000000000220; Lewis SR, Butler AR, Parker J, Cook TM, Schofield-Robinson OJ, Smith AF. Videolaryngoscopy versus direct laryngoscopy for adult patients requiring tracheal intubation: a Cochrane Systematic Review. Br J Anaesth. 2017;119(3):369-383. doi:10.1093/bja/aex228; Patel A, Nouraei SA. Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways. Anaesthesia. 2015;70(3):323-329. doi:10.1111/anae.12923; Turner JS, Bucca AW, Propst SL, et al. Association of checklist use in endotracheal intubation with clinically important outcomes: a systematic review and meta-analysis. JAMA Netw Open. 2020;3(7):e209278. doi:10.1001/jamanetworkopen.2020.9278; Vasan NR, Kosik E, Collins B, Clampitt M. Surgeon-performed intubation in awake patients utilising an anterior commissure laryngoscope with bougie: a retrospective case series. J Laryngol Otol. 2019;133(11):986-991. doi:10.1017/S0022215119002214; Yoon U, Yuan I. Modified nasal trumpet for airway management. Anesthesiology. 2016;125(3):596. doi:10.1097/ALN.0000000000001054.

Disclosures

For this program, members of the faculty and planning committee reported nothing relevant to disclose. Dr. Lyaker’s lecture includes information related to the off-label or investigational use of a therapy, product, or device.

Acknowledgements

Dr. Lyaker was recorded at the 49th Annual Mid-Year Seminar of the American Osteopathic College of Anesthesiologists, held March 25-27, 2022, and presented by the American Osteopathic College of Anesthesiologists. For information about upcoming CME activities from this presenter, please visit aocaonline.org. Audio Digest thanks the speakers and presenters for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 1.00 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 1.00 CE contact hours.

Lecture ID:

AN643001

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.