Awake intubation distribution

1. Let’s Revisit Awake
Intubation
Clifford Gonzales
CRNA, PhD
Wake Forest School of Medicine
Nurse Anesthesia Program

2. Objectives
• After the presentation, participants will be
able to:
 Identify physical assessments for
ventilation and tracheal intubation.
 Describe the innervation of the
airway.
 State the modalities of anesthetizing
the airway.

3. Closed Claims
• 1984- ASA Closed Claims Project
Anesthesiol. 1999; 91:552-556

4. Closed Claims
• 1970-2007 Closed claims analysis
Best Pract Res Clin Anaesthesiol. 2011; 25:263-276
0%
10%
20%
30%
Esophagealintubation
Inadequateoxygenation/ventilation
DifficultIntubation
Aspiration
Proportionofrespiratoryclaimsintimeperiod(%)
1970-1989
1990-2007

5. Closed Claims
1980-2011 Closed Claims Analysis
• 10,093 closed claims
• Airway injuries from general
anesthesia.
https://depts.washington.edu/asaccp/pubs/herring-jc-posner-kl-domino-kb-airway-injuries-associated-
general-anesthesia-closed-claims

6. Airway Management
Closed Claims
1980-2011 Closed Claims Analysis
0%
10%
20%
30%
40%
50%
Difficult Intubation (DI) Pharyngeal/Esophageal Perforation (P/EP)
ProportionofAirwayInjures
1980-1999
2000-2011
https://depts.washington.edu/asaccp/pubs/herring-jc-posner-kl-domino-kb-airway-injuries-associated-general-anesthesia-
closed-claims

7. Closed Claims
Limitations of closed claims
Inaccurate numerator and denominator
Geographical representations
Retrospective studies

8. Closed Claims
Lessons from closed claims
Securing an airway is a team effort
Avoid haste with preparation
(assessment, planning, communication)
Anatomy and physiology,
pharmacological, and equipment
knowledge needs to be current

9. Airway Assessment
Table 4a: Comparison of various predictive tests
Assessment Sensitivity (%) Specificity (%) PPV (%) NPV (%)
IIG 13.43 98.31 56.25 87.50
HNM 07.46 93.95 16.67 86.22
MMT 70.15 61.02 22.60 92.65
TMD 07.46 98.06 38.46 86.72
RHTMD 71.64 92.01 59.26 95.24
ULBT 74.63 91.53 58.82 95.70
IIG=Inter-incisor gap; HNM=Head and neck movement; MMT=Modified
mallampatti test; TMD=Thyromental distance; RHTMD=Ratio of height to
thyromental distance; ULBT=Upper lip bite test
J Aenesthesiol Clin Pharmacol, 2013, 29(2): 191-195

10. Airway Assessment
Assessment of ability to mask ventilate
M
O
A
N
S
Mask seal
Obese
Age
Nose, no teeth, neck mobility
stiffness

11. Airway Assessment
Assessment of ability to intubate
L
E
M
O
N
Look externally
Evaluate (TMD, RHTTMD, ULBT)
Mallampati
Obstruction
Neck mobility
Multivariate assessment to predict DI

12. Difficulty Airway Algorithm
• ASA Difficult Airway Algorithm
• 1. Assess the likelihood and clinical impact of basic management problems:
• Difficulty with patient cooperation or consent
• Difficult mask ventilation
• Difficult supraglottic airway placement
• Difficult laryngoscopy
• Difficult intubation
• Difficult surgical airway access
• 2. Actively pursue opportunities to deliver supplemental oxygen throughout the
process of difficult airway management.
• 3. Consider the relative merits and feasibility of basic management choices:
• Awake intubation vs. intubation after induction of general anesthesia
• Non-invasive technique vs. invasive techniques for the initial approach to intubation
• Video-assisted laryngoscopy as an initial approach to intubation
• Preservation vs. ablation of spontaneous ventilation
Anesthesiology 2013; 118:251-270

13. Difficulty Airway Algorithm
• ASA Difficulty Airway Algorithm
Anesthesiology 2013; 118:251-270

14. Difficulty Airway Algorithm
• Unanticipated Difficulty Airway Algorithm
Brit J of Anesthet, 2015; 115(6):827-848

15. Awake Intubation
• Indications
 Co-morbidities (cervical conditions,
intolerance to apnea, etc.)
 Risk of aspirations
 Difficult airway assessment
 Emergency

16. Awake Intubation
• Explanation to patient
• Pharmacological
• Equipment
• Personnel

17. Awake Intubation
• Pharmacological
 Antisialagogue
 Dilators
 Sedation
 Topical anesthesia
 Emergency

18. Awake Intubation
• Equipment
 Airway visualization
 Adjuncts
 Monitors
 Emergency

19. Awake Intubation
• Personnel
 Other anesthesia providers
 Surgeon/s
 Nurses

20. Awake Intubation
• Various local anesthetics (LA) can be used
for anesthetizing the airway.
• Lidocaine has an advantage because of:
 Availability of different formularies
and preparation.
 Wider margin of safety

21. Awake Intubation
Airway innervation
• Nasopharynx- Trigeminal nerve
(opthalmic and maxillary branch)
• Oropharynx- CNIX
(Glossopharyngeal nerve)
• Laryngopharynx- superior
laryngeal nerve
• Larynx and trachea- recurrent
laryngeal nerve

22. Common Methods of Anesthetizing
the Airway
Nasopharynx
• ½ in of lidocaine 5% at each nares (50mg)
OR
• 2 ml Lidocaine 4% aerosol spray (80mg)

23. Common Methods of Anesthetizing
the Airway
Oropharynx
•Apply 2 inches of 5% Lidocaine
ointment on a tongue depressor
(200mg)
OR
• Instruct patient to gurgle 5 ml of
Lidocaine 4% topical solution (may
need to do this twice) (200 mg or
400mg)

24. Common Methods of Anesthetizing
the Airway
Oropharynx
OR
• Place ½ in. of 5% lidocaine at a cotton tip
applicator and apply it at the base of
palatoglossal arch (5 min each side) (100
mg)
OR
• Using a 22g spinal needle, administer 2% of
Lidocaine injection solution to both bases of
the palatoglossal arch (80mg)

25. Common Methods of Anesthetizing
the Airway
Laryngopharynx (Superior Laryngeal Nerve)
•Administer 5 ml of 4% lidocaine injection
solution via nebulization (200 mg)
OR
•Drip 5 ml of 2% lidocaine viscous solution to
the back of the patient’s tongue (1-2 min)
(200mg)

26. Common Methods of Anesthetizing
the Airway
Laryngopharynx (Superior Laryngeal Nerve)
OR
• Using a 23 G needle, administer 3 ml of
2% lidocaine injection solution at both
lateral sides of the neck between the
thyroid cartilage and hyoid bone (120mg).

27. Common Methods of Anesthetizing
the Airway
Recurrent Laryngeal Nerve
• Lidocaine nebulization may suffice
OR
• Using epidural cath through the fiberoptic,
5ml of lidocaine 4% to the trachea (200mg)
OR
• Using a 20 G needle, administer 5 ml of 4%
lidocaine injection solution to the
Cricothyroid membrane (200mg)

28. Awake Intubation
Calculation of lidocaine total
administered dose:
1. Nasopharynx (ointment)= 50mg
2. Glossopharyngeal nerve= 80mg
3. Superior Laryngeal nerve= 120mg
4. Recurrent Laryngeal nerve=200mg
Total without nasopharynx = 400mg
Total with nasopharynx = 450mg

29. Awake Intubation
Lidocaine toxicity
• Legendary: 5mg/kg
• Normal therapeutic range for ventricular
arrythmias: 2-5mcg/ml
• Various pharmacological factors affect
lidocaine plasma level

30. Awake Intubation