Acute Airway Management

Author Credentials 

James J. Daniero, MD, MS
Assistant Professor
Department of Otolaryngology, Head and Neck Surgery
University of Virginia
Charlottesville, VA
jdaniero@virginia.edu

Module Summary

Acute airway management requires clear communication between health care providers to develop a plan with multiple agreed upon contingencies. Development of this tiered approach to establishing a safe airway also requires utilization of a baseline algorithm and the flexibility to rapidly apply patient-specific considerations. The otolaryngologist maintains the most intimate knowledge of the altered airway and is in sole possession of the full range of skills required to definitively address the difficult airway. Early recognition of airway compromise is critical to minimizing morbidity and mortality. Therefore, it is the responsibility of an otolaryngologist to maintain familiarity with relevant laryngeal pathology and the medical, procedural, and surgical skills for acute airway management.

Module Learning Objectives 
  1. Develop a differential diagnosis for stridor due to upper airway obstruction.
  2. Recognize a critical airway situation early in the disease process and intervene appropriately to maintain secure airway access.
  3. Develop a tiered algorithm for acute airway management, including several standby options.
  4. Appraise the surgical and non-surgical options for acute airway management and the potential associated complications.
  5. Assess the various devices available to assist in difficult airway management and their associated advantages and disadvantages.

Embryology

Learning Objectives 

Recognize the syndromes and malformations associated with congenital airway obstruction.

  1. Pierre Robin sequence
  2. Treacher Collins syndrome
  3. Goldenhar syndrome
  4. Subglottic stenosis
  5. Laryngeal web
  6. Laryngomalacia
References 
  1. Meyer A, Lidsky M, Sampson D, Lander T, Liu M, Sidman J. Airway interventions in children with Pierre Robin Sequence. Otolaryngol Head Neck Surg. 2008 Jun;138(6):782-787. 
  2. Altman KW, Wetmore RF, Marsh RR. Congenital airway abnormalities in patients requiring hospitalization. Arch Otolaryngol Head Neck Surg. 1999 May;125(5):525-528. 
  3. Sculerati N, Gottlieb M, Zimbler M, Chibbaro P, McCarthy J. Airway management in children with major craniofacial anomalies. Laryngoscope. 1998 Dec;108(12):1806-1812. 
  4. Kakodkar KA, Schroeder JW Jr, Holinger LD. Laryngeal development and anatomy. Adv Otorhinolaryngol. 2012;73:1-11. 

Anatomy

Learning Objectives 
  1. Localize a lesion of the upper airway to a specific laryngeal subsite(s): supraglottis, glottis, subglottis, and/or trachea.
  2. Describe the basic anatomy of the upper airway and define the anatomic landmarks that distinguish them:
    1. Nasal cavity
    2. Nasopharynx
    3. Oral cavity
    4. Oropharynx
    5. Hypopharynx
    6. Larynx
      1. Supraglottis
      2. Glottis
      3. Subglottis
    7. Trachea
References 
  1. Liess BD, Scheidt TD, Templer JW. The difficult airway. Otolaryngol Clin North Am. 2008;41:567-580. 
  2. Kakodkar KA, Schroeder JW Jr, Holinger LD. Laryngeal development and anatomy. Adv Otorhinolaryngol. 2012;73:1-11.

Pathogenesis

Learning Objectives 
  1. Differentiate the types of angioedema.
    1. Hereditary angioedema (HAE)
      1. HAE Type I
      2. HAE Type II
      3. Hereditary with normal C1 inhibitor (former Type III)
    2. Iatrogenic angioedema
      1. Angiotensin converting enzyme inhibitor
    3. Acquired angioedema
    4. Allergic (histamine mediated)
    5. Idiopathic
  2. Recognize acute epiglottitis
    1. Identify likely pathogens
  3. Describe the indications and contraindications to intubation in the setting of blunt laryngeal trauma.
References 
  1. LoVerde D, Files DC, Krishnaswamy G. Angioedema. Crit Care Med. 2017;45:725-735.
  2. Brook CD, Devaiah AK, Davis EM. Angioedema of the upper aerodigestive tract: risk factors associated with airway intervention and management algorithm. Int Forum Allergy Rhinol. 2014;4:239-245. 
  3. Shah RK, Stocks C. Epiglottitis in the United States: national trends, variances, prognosis, and management. Laryngoscope. 2010;120:1256-1262.
  4. Schaefer SD. Management of acute blunt and penetrating external laryngeal trauma. Laryngoscope. 2014;124:233-244. 

Genetics

Learning Objectives 

Discuss the inheritance patterns of hereditary angioedema.

References 
  1. LoVerde D, Files DC, Krishnaswamy G. Angioedema. Crit Care Med. 2017;45:725-735. 

Patient Evaluation

Learning Objectives 
  1. Describe the presenting symptoms of acute airway obstruction.
  2. Discuss the reliability of the vital signs.
  3. Differentiate between “cannot ventilate” and “cannot intubate” situations.
    1. Discuss acuity of both situations.
    2. Recognize the factors associated with difficult ventilation.
      1. Beard
      2. Obese
      3. Edentulous
      4. Swelling
      5. Bleeding
    3. Recognize the factors associated with difficult intubation.
      1. Poor neck extension
      2. Short thyromental distance
      3. Trismus
      4. Tori
      5. Macroglossia
      6. Radiation fibrosis
      7. Obstructing tumor
      8. Bleeding
  4. Review indications for awake fiberoptic intubation.
  5. Review indications for awake tracheotomy.
  6. Review indications for cricothyroidotomy.
References 
  1. Saddawi-Konefka D, Hung S, Kacmarek R, Jiang Y. Optimizing Mask Ventilation: Literature Review and Development of a Conceptual Framework. Respir Care. 2015;60:1834-1840. 
  2. Liess BD, Scheidt TD, Templer JW. The difficult airway. Otolaryngol Clin North Am. 2008;41:567-580. 
  3. Collins SR, Blank RS. Fiberoptic intubation: an overview and update. Respir Care. 2014;59:865-878; discussion 878-880. 

Measurement of Functional Status

Learning Objectives 
  1. Explain the role of pre-oxygenation in management of the acute airway.
  2. Describe the time-course of pulse oximetry and utility in monitoring a patient with impending airway obstruction.
  3. Describe the changes of upper airway obstruction to spirometry (flow-volume loop).
References 
  1. Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med. 2012 Mar;59(3):165-75. 
  2. Nouraei SM, Franco RA, Dowdall JR, Nouraei SA, Mills H, Virk JS, Sandhu GS, Polkey M. Physiology-based minimum clinically important difference thresholds in adult laryngotracheal stenosis. Laryngoscope. 2014;124:2313-2320. 

Imaging

Learning Objectives 
  1. Identify upper airway narrowing on lateral neck films
    1. Steeple sign
    2. Thumb sign
  2. Identify site of airway obstruction on CT scan
References 
  1. Takata M, Fujikawa T, Goto R. Thumb sign: acute epiglottitis. BMJ Case Rep. 2016 May 31;2016.
  2. Huang CC, Shih SL. Images in clinical medicine. Steeple sign of croup. N Engl J Med. 2012;367:66. 

Treatment

Learning Objectives 
  1. Describe the proper patient positioning for optimal mask ventilation.
  2. Describe the proper patient positioning for standard intubation.
  3. Discuss the indications and benefits for difficult airway equipment.
    1. Oral/Nasal airway
    2. High-flow nasal cannula
    3. Laryngeal mask airway
    4. Intubating laryngeal mask airway
    5. Fiberoptic-guided intubation
    6. Rigid bronchoscope
    7. Jet Cannula
References 
  1. Hernandez MR, Klock PA Jr, Ovassapian A. Evolution of the extraglottic airway: a review of its history, applications, and practical tips for success. Anesth Analg. 2012;114(2):349-68.
  2. Apfelbaum JL, Hagberg CA, Caplan RA, Blitt CD, Connis RT, Nickinovich DG, Hagberg CA, Caplan RA, Benumof JL, Berry FA, Blitt CD, Bode RH, Cheney FW, Connis RT, Guidry OF, Nickinovich DG, Ovassapian A; American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013;118(2):251-70.

Medical Therapies

Learning Objectives 
  1. Determine the appropriate steroid choice, differentiating by onset and duration of effect in managing acute airway edema.
  2. Discuss the acute medical management of angioedema.
References 
  1. LoVerde D, Files DC, Krishnaswamy G. Angioedema. Crit Care Med. 2017;45:725-735.
  2. Roberts RJ, Welch SM, Devlin JW. Corticosteroids for prevention of postextubation laryngeal edema in adults. Ann Pharmacother. 2008 May;42:686-691. 

Pharmacology

Learning Objectives 
  1. Know the maximum lidocaine dose.
  2. Explain the appropriate use of topical lidocaine for awake intubation.
  3. Know mechanism of action of glucocorticoids used for airway edema.
References 
  1. Xue FS, Liu HP, He N, Xu YC, Yang QY, Liao X, Xu XZ, Guo XL, Zhang YM. Spray-as-you-go airway topical anesthesia in patients with a difficult airway: a randomized, double-blind comparison of 2% and 4% lidocaine. Anesth Analg. 2009;108:536-543. 
  2. Anene O, Meert KL, Uy H, Simpson P, Sarnaik AP. Dexamethasone for the prevention of postextubation airway obstruction: a prospective, randomized, double-blind, placebo-controlled trial. Crit Care Med. 1996 Oct;24:1666-1669. 
  3. Roberts RJ, Welch SM, Devlin JW. Corticosteroids for prevention of postextubation laryngeal edema in adults. Ann Pharmacother. 2008 May;42:686-691.

Surgical Therapies

Learning Objectives 
  1. Explain the steps required to perform awake fiberoptic intubation.
  2. Discuss the role of cricothyroidotomy in securing the airway during an emergency situation.
  3. Explain the indications and considerations for awake tracheotomy.
References 
  1. Yuen HW, Loy AH, Johari S. Urgent awake tracheotomy for impending airway obstruction. Otolaryngol Head Neck Surg. 2007;136:838-842. 
  2. Liess BD, Scheidt TD, Templer JW. The difficult airway. Otolaryngol Clin North Am. 2008;41:567-580. 
  3. Collins SR, Blank RS. Fiberoptic intubation: an overview and update. Respir Care. 2014;59:865-878; discussion 878-880. 

Staging

Learning Objectives 
  1. Discuss the factors involved in predicting a difficult airway situation.
  2. Explain the difficult airway algorithm.
  3. Describe the Mallampati classification and associated risk of difficult ventilation and intubation.
  4. Describe the grades of laryngoscopy using the Cormack Lehane scale.
References 
  1. Samsoon G, Young J. Difficult tracheal intubation: a retrospective study. Anaesthesia. 1987 May;42(5):487-90.
  2. Cormack RS, Lehane J. Difficult tracheal intubation in obstetrics. Anaesthesia.1984 Nov;39(11):1105-11.
  3. Apfelbaum JL, Hagberg CA, Caplan RA, Blitt CD, Connis RT, Nickinovich DG, Hagberg CA, Caplan RA, Benumof JL, Berry FA, Blitt CD, Bode RH, Cheney FW, Connis RT, Guidry OF, Nickinovich DG, Ovassapian A; American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013 Feb;118(2):251-70. 

Case Studies

  1. 43-year-old African-American female with 18 month history of shortness of breath presents to the outpatient clinic now unable to walk more than a few feet without dyspnea. Exam is notable for stridor at rest and morbid obesity. Flexible laryngoscopy reveals subglottic stenosis with 3mm diameter airway. Chest x-ray reveals hilar adenopathy.
    1. Requires ambulance transfer directly to the hospital proceeding to the operating room without delay.
    2. Unclear if direct laryngoscopy is possible; patient will need awake tracheotomy below the level of the stenosis.
    3. Chest x-ray helpful to determine length of stenosis prior to tracheotomy; cat-scan not advisable until airway secured.
    4. The leading diagnosis is sarcoidosis involving the subglottis.
  2. 78-year-old Caucasian male on warfarin tripped and struck neck on laundry basket. Noted bruising of anterior neck, immediate hoarse voice, and subsequently has developed moderate shortness of breath. Evaluation in ED includes flexible laryngoscopy which reveals a large hematoma of the left false vocal fold and limited ability to visualize the airway at the level of the glottis.
    1. In the absence of crepitus or subcutaneous emphysema, awake fiberoptic intubation is the best option to secure the airway. Alternatively, reversal of anticoagulation and awake tracheotomy could be performed.
    2. Cat-scan should be obtained after the airway is secured to identify possible injury to the laryngeal framework.
  3. 63-year-old African-American female began taking new blood pressure medication 3 days ago and has experienced rapid onset of tongue swelling and shortness of breath. Flexible laryngoscopy reveals diffuse edema of the airway from the nasopharynx down to the larynx.
    1. Proceed directly to the operating room for awake transnasal fiberoptic intubation.
    2. Avoid all sedation.
    3. Tracheotomy/cricothyroidotomy instrument setup as emergency backup plan.
    4. Stop ACE-inhibitor and edema should resolve within 72 hours. If not, consider other cause.
References 
  1. Yuen HW, Loy AH, Johari S. Urgent awake tracheotomy for impending airway obstruction. Otolaryngol Head Neck Surg. 2007;136:838-842. 
  2. Liess BD, Scheidt TD, Templer JW. The difficult airway. Otolaryngol Clin North Am. 2008;41:567-580. 
  3. Brook CD, Devaiah AK, Davis EM. Angioedema of the upper aerodigestive tract: risk factors associated with airway intervention and management algorithm. Int Forum Allergy Rhinol. 2014;4:239-245. 

Complications

Learning Objectives 
  1. Recognize the signs of methemoglobinemia when preparing the airway for awake intubation.
  2. Explain the treatment of methemoglobinemia.
  3. Know the signs and symptoms of lidocaine toxicity.
  4. Recognize the contraindications to endotracheal intubation in the setting of blunt laryngeal trauma.
References 
  1. Kern K, Langevin PB, Dunn BM. Methemoglobinemia after topical anesthesia with lidocaine and benzocaine for a difficult intubation. J Clin Anesth. 2000;12:167-72. 
  2. Langmack EL, Martin RJ, Pak J, Kraft M. Serum lidocaine concentrations in asthmatics undergoing research bronchoscopy. Chest. 2000;117:1055-1060. 
  3. Schaefer SD. Management of acute blunt and penetrating external laryngeal trauma. Laryngoscope. 2014;124:233-244. 

Review

Review Questions 
  1. What is the accepted maximum dose of lidocaine that can be administered topically to the airway?
  2. Name 3 factors that contribute to difficult ventilation, but not difficult intubation.
  3. Name 3 factors that contribute to difficult intubation, but not difficult ventilation.
  4. What is the thumb sign when visualizing a lateral neck x-ray?
  5. What is the quickest and safest approach to the airway and last option for almost all airway algorithms?
  6. What is the most common cause of neonatal stridor?
References 
  1. Langmack EL, Martin RJ, Pak J, Kraft M. Serum lidocaine concentrations in asthmatics undergoing research bronchoscopy. Chest. 2000;117:1055-1060. 
  2. Apfelbaum JL, Hagberg CA, Caplan RA, Blitt CD, Connis RT, Nickinovich DG, Hagberg CA, Caplan RA, Benumof JL, Berry FA, Blitt CD, Bode RH, Cheney FW, Connis RT, Guidry OF, Nickinovich DG, Ovassapian A; American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013 Feb;118(2):251-70. 
  3. Takata M, Fujikawa T, Goto R. Thumb sign: acute epiglottitis. BMJ Case Rep. published online:2016 May 31. 
  4. Altman KW, Wetmore RF, Marsh RR. Congenital airway abnormalities in patients requiring hospitalization. Arch Otolaryngol Head Neck Surg. 1999 May;125(5):525-528. 
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