Chapter 13 Airway Management
1. What is the definition of difficult mask ventilation?
2. What is the incidence of difficult mask ventilation?
3. What is the definition of difficult tracheal intubation/laryngoscopy?
4. What is the incidence of difficult tracheal intubation/laryngoscopy?
Anatomy and physiology of the upper airway
6. How does resistance to airflow through the nasal passages compare to that through the mouth?
7. What nerves innervate the nasal mucosa?
8. What nerves innervate the hard and soft palate?
9. What nerve provides sensation to the anterior two thirds of the tongue?
10. What nerve innervates the posterior third of the tongue, the soft palate, and the oropharynx?
11. What are the three components of the pharynx?
12. What nerves innervate the pharynx?
13. Complete the following table: (223, Table 16-1, Motor and Sensory Innervation of Larynx)
| Nerve | Sensory | Motor |
|---|---|---|
| Superior laryngeal, internal division |
||
| Superior laryngeal, external division |
||
| Recurrent laryngeal |
14. Where is the narrowest part of the adult airway?
15. What is special about the cricoid cartilage compared with the other tracheal cartilages?
Airway assessment
16. What is the purpose of the Mallampati classification system?
17. Describe the observer/patient position during Mallampati classification.
18. Describe the Mallampati classes.
19. What is the purpose of the Cormack and Lehane score?
20. Describe the Cormack and Lehane grades.
21. What is the purpose of the upper lip bite test (ULBT)?
22. Describe the upper lip bite test (ULBT) classes.
23. What three axes must be aligned to obtain a line of vision during direct laryngoscopy? How is this accomplished? What is this final position called?
24. What is the concern with a “short” thyromental distance?
25. What is the concern with a decreased submandibular compliance?
26. What position is associated with improved alignment of the three axes to obtain a line of vision during laryngoscopy in obese patients?
27. What maneuver facilitates identification of the cricoid cartilage in patients who do not have a prominent thyroid cartilage?
Airway management techniques
28. What is “preoxygenation” prior to the induction of anesthesia? What is its value?
29. How is preoxygenation accomplished?
30. Name ten independent variables that are associated with difficult facemask ventilation.
31. Why is it important to limit ventilation pressure to less than 20 cm H2O during facemask ventilation?
32. What are contraindications to nasal airway placement?
33. What are some indications for endotracheal intubation?
34. What is another name for cricoid pressure and how is it performed?
35. What is the purpose of cricoid pressure?
36. Describe the proper placement of the tip of a curved (Macintosh) laryngoscope blade versus that of a straight (Miller) laryngoscope blade for exposure of the glottic opening during laryngoscopy.
37. Describe the OELM and BURP maneuvers. What is their purpose?
38. How are endotracheal tubes sized?
39. Why are endotracheal tubes radiopaque and transparent?
40. Why are low-pressure, high-volume cuffs on endotracheal tubes preferred?
41. What are some serious complications attributable to endotracheal cuff pressures?
42. Name some stylets that can be used to facilitate endotracheal intubation.
43. What are some methods to confirm the correct placement of an endotracheal tube?
44. When is an awake fiberoptic endotracheal intubation most frequently chosen?
45. Why is fiberoptic endotracheal intubation recommended for patients with unstable cervical spines?
46. Why is fiberoptic endotracheal intubation recommended for patients who have sustained an injury to the upper airway from either blunt or penetrating trauma?
47. What is an absolute contraindication to fiberoptic endotracheal intubation?
48. What are some relative contraindications to fiberoptic endotracheal intubation?
49. What are some advantages and disadvantages of nasal fiberoptic endotracheal intubation?
50. Why should an antisialagogue be given before fiberoptic endotracheal intubation?
51. On what basis is the choice of sedation for an awake fiberoptic tracheal intubation made?
52. Describe preparation of the nose and nasopharynx for nasal fiberoptic tracheal intubation.
53. Describe preparation of the tongue and oropharynx for nasal or oral fiberoptic tracheal intubation.
54. Describe preparation of the larynx and trachea for nasal or oral fiberoptic tracheal intubation.
55. Why is lidocaine the preferred airway topical local anesthetic?
56. Name two blocks that can be performed to topicalize the larynx and trachea.
Flexible fiberoptic laryngoscopy
57. How can the risks of mucosal trauma or submucosal bleeding with nasal endotracheal intubation be minimized?
58. What advantages does inflation of the endotracheal tube cuff during advancement with the fiberoptic scope offer?
59. How is endotracheal tube depth verified during fiberoptic intubation?
60. What are possible causes of resistance when removing the fiberoptic bronchoscope?
61. What is the utility of oral intubating airways during oral fiberoptic endotracheal tracheal intubation?
62. Why is visualization more difficult during fiberoptic endotracheal tracheal intubation in an asleep patient?
63. Why is having a second person trained in anesthesia delivery present recommended for fiberoptic endotracheal tracheal intubation in an asleep patient?
Supraglottic airway devices
Tracheal extubation
76. Why is tracheal extubation during a light level of anesthesia dangerous?
77. What is laryngospasm? When is it most likely to occur?
78. How should laryngospasm be treated?
79. When is deep tracheal extubation contraindicated?
80. What are the steps of tracheal extubation?
81. What is the most common complication during direct laryngoscopy?
82. Describe endotracheal tube movement during head flexion and extension.
83. What are the two most serious complications after tracheal extubation?
84. What is the major complication of prolonged tracheal intubation?
Airway management in infants and children
85. What are some differences between the infant and the adult airway? At what age does the pediatric upper airway take on more adultlike characteristics?
86. Contrast the location of the larynx in an infant versus an adult. What effect does this have on the tongue?
87. Contrast the size of an infant’s tongue in proportion to the size of the mouth with that of an adult. What are the consequences of this?
88. Contrast an infant’s epiglottis with that of an adult.
89. What advantages do straight laryngoscopes offer over curved laryngoscopes when intubating an infant or small child?
90. What is the narrowest portion of an infant’s airway versus an adult airway?
91. What is the correct size of an uncuffed endotracheal tube in infants and children?
92. Can cuffed endotracheal tubes be safely used in infants and children? What if nitrous oxide is used during the anesthetic?
93. What are the dangers of an endotracheal tube that is too large for infants and children?
94. Contrast proper head and neck positioning of an adult with that of an infant during direct laryngoscopy.
95. What is different about an infant’s nares compared to an adult’s? Why is this important?
96. Why is a history of snoring important in infants and children?
97. Why is premedication useful in pediatric anesthesia? At what age does this become important?
98. What is the dose of oral midazolam for infants or children? What is the maximum oral dose? What if the child is uncooperative with taking oral midazolam?
99. Describe an inhaled induction in a child. When should the nitrous oxide be discontinued?
100. Describe maneuvers to overcome airway obstruction during mask induction in infants and children.
101. What determines the appropriate size of an LMA for use in infants and children?
102. What is the LMA Flexible? What advantages does it offer?
103. What advantage does the Air-Q intubating laryngeal airway (ILA) have over an LMA?
104. What formula is often used to estimate the appropriate-sized endotracheal tubes for infants and children?
105. Is the formula used to estimate the appropriate-sized endotracheal tube for infants and children applicable for cuffed or uncuffed endotracheal tubes?
106. How is the formula used to estimate the appropriate-sized endotracheal tubes for infants and children adapted for cuffed endotracheal tubes?
107. What three advantages do Microcuff endotracheal tubes have over conventional pediatric cuffed endotracheal tubes?
108. Are stylets useful in intubating infants and children?
109. What is the disadvantage of a straight laryngoscope blade compared to a curved blade?
110. Describe the most useful sizes of laryngoscope blades according to age.
111. What is the most important first step when an unexpected difficult airway occurs in pediatric patients?
112. Why should repeated attempts at direct laryngoscopy be avoided? What should be done instead?
113. Is an awake fiberoptic endotracheal intubation usually an option in managing an expected pediatric difficult airway?
114. What personnel and equipment should be in the operating room before induction of anesthesia in a pediatric patient with an expected difficult airway?
115. What airway devices are available in smaller sizes to facilitate intubation of a child with a difficult airway?
116. Why is tracheal extubation in infants and children riskier than that of adults?
117. When does postextubation croup most commonly occur? Why is this important?
118. What are the clinical manifestations of postextubation croup?
119. How is postextubation croup treated?
120. Why is obstructive sleep apnea especially important in infants and children?
121. How should opiate therapy be managed in an infant or child with obstructive sleep apnea?
122. Describe tracheal extubation and postoperative monitoring for infants and children with obstructive sleep apnea.
123. How should extubation after a difficult intubation be handled in infants and children?
Answers*
1. Difficult mask ventilation is defined as an inability to maintain oxygen saturation (Spo2) greater than 90% or an inability to prevent or reverse the signs of inadequate ventilation. (220)
2. The incidence of difficult mask ventilation ranges from 0.07% to 5%. (220)
3. Difficult tracheal intubation/laryngoscopy is defined as successful intubation requiring more than three attempts or taking longer than 10 minutes. (220)
4. Difficult tracheal intubation/laryngoscopy occurs in 1.1% to 8.5% of patients. (220)
5. Failed tracheal intubation occurs at an incidence of 0.01% to 0.03%. (220)
Anatomy and physiology of the upper airway
6. Resistance to airflow through the nasal passages is twice that through the mouth and accounts for approximately two thirds of total airway resistance. (220)
7. The ophthalmic (V1) and maxillary divisions (V2) of the trigeminal nerve (cranial nerve V) provide innervation to the nasal mucosa as the anterior ethmoidal, nasopalatine, and sphenopalatine nerves. (220, Figure 16-2)
8. The palatine nerves branch from the sphenopalatine ganglion to innervate the hard and soft palate. (220, Figure 16-2)
9. The mandibular division (V3) of the trigeminal nerve (cranial nerve V) forms the lingual nerve, which provides sensation to the anterior two thirds of the tongue. (220, Figure 16-3)
10. The posterior third of the tongue, the soft palate, and the oropharynx are innervated by the glossopharyngeal nerve (cranial nerve IX). (220, Figure 16-4)
11. The three components of the pharynx are the nasopharynx, the oropharynx, and the hypopharynx. (220)
12. The pharynx is innervated by cranial nerves IX (glossopharyngeal) and X (vagus). (220, Figures 16-4 and 16-5)
| Nerve | Sensory | Motor |
|---|---|---|
| Superior laryngeal, internal division |
Epiglottis Base of tongue Supraglottic mucosa Thyroepiglottic joint Cricothyroid joint |
None |
| Superior laryngeal, external division |
Anterior subglottic mucosa | Cricothyroid m. |
| Recurrent laryngeal |
