Title: Difficult%20Airway%20Management%20in%20Anesthesia%20%20Part%20II
1Difficult Airway Management in Anesthesia Part
II
- Chan Wei-Hung MD
- Department of Anesthesiology
- National Taiwan University Hospital
2Awake Intubation Topicalization of Airway
- This should be done in such an order
- Nasopharynx
- Oropharynx
- Vocal cord and trachea
Generally speaking, vocal cord and its vincity is
the most sensitive site and the most common
barrier to successful awake fiberoptic
intubation others are usually tolerable under
the spray of local anesthetics.
3Sensory Innervations of Airway
- Nasal mucosa sphenopalatine ganglion (V2)
anterior ethmoidal nerve (ciliary ganglion) - Oropharynx and supraglottic region
glossopharyngeal nerve - Larynx superior laryngeal nerve (internal
branch) - Trachea recurrent laryngeal nerve
4Innervation of Nasopharynx
5Anesthesia of Nasopharynx
6Anesthesia of Nasopharynx
7Drugs to Use
- 4 lidocaine with 1200,000 epinephrine
- 4 lidocaine with 0.250.5 phenylephrine
- Lower concentration of lidocaine makes a slower
onset. - Apply bilaterally wait 23 min to take effect.
8A Case Report
- Intraoperative death of a 21-kg, 4-yr-old boy
during bilateral myringotomies and adenoidectomy - Unmeasured amount of 0.5 phenylephrine on the
surgical site to control bleeding - BP was 180/110 mmHg and heart rate was 160
beats/min - 2.5 mg labetalol was given
- Bradycardia developed, and copious amounts of
pink, frothy fluid were found from ET tube. - He died 16 h later in ICU.
. Anesthesiology 92(3)859-64, 2000
9Guidelines for Usage
- Phenylephrine for adults should not exceed 0.5 mg
or 20 µg/kg in children. - Mild-to-moderate hypertension resulting from
phenylephrine use, in a healthy individual,
should be closely monitored for 1015 min before
antihypertensive medications - Direct vasodilators or a antagonists are
appropriate treatments. - The use of ß blockers and calcium-channel
blockers should be avoided. - Glucagon may be used to treat ß blocker-induced
heart failure / pulmonary edema.
. Anesthesiology 92(3)859-64, 2000
10Lubrication of the Nasal Passage
- 7.5 / 7.0 mm nasopharyngeal airway soaked in
viscous lidocaine - Determination of the nostril
- Determination of the tube size (the bigger the
better ?)
11Glossopharyngeal Nerve Block
2ml of 12 lidocaine each side Aspiration before
injection May have the patient in sitting or
back-up position
26 spinal needle Advance 0.5 cm into mucosa
12Superior Laryngeal Nerve Block
- The patients neck is slightly hyperextended.
- Superior border of lateral wing of thyroid
cartilage and greater cornu of hyoid bone are
palpated. - Advance the needle just under the greater cornu
of hyoid bone until walk-off through the firm
thyrohyoid membrane, aspirate then inject 12
xylocaine 23 cc each side.
13Superior Laryngeal Nerve Block
14Superior Laryngeal Nerve Block
15Transtracheal Injection
- The patients neck is slightly hyperextended.
- Drug 4 Lidocaine 2 ml or 2 4 ml (2 needs
longer onset time, maybe 10 min) - 22 IV cath, through cricothyroid membrane, ????,
???air bubbles, ??????cough - NPO?????
16Spray As You Go
- Inject 0.2-1.0 ml 24 lidocaine via suction
channel of fiberoscope (esp. near the vocal
cord). - Remember to hold the suction tubing when inject.
- Wait 30 to 60 sec. Then advance again.
- Not as effective as nerve block.
17The Importance of Being Anesthetized
18Awake Intubation
- Planned or after failed intubation
- Fiberoptic intubation
- Retrograde intubation
- Blind nasal intubation
These techniques are essentially not for true
emergency situations (time-consuming).
19Awake Fiberoptic Intubation Nasal Approach
20Tube First or Scope First?
- ET tube first
- Higher possibility to cause bleeding
- Patients feel uneasy with tube in the nasal
passage. - Scope first
- Fiberoscope has the chance to divert from
midline. - Passage of ET tube through nasopharynx is not
assured.
21Tube First Technique
- Choice of tube size the size does not matter!
- Put the tube in warm water for 5 min
- Choice of nostril left side is preferable
- Do not do it forcefully!! (To shift to a smaller
ET tube is a virtue.) - Two points of high resistance will be met.
- After the second high resistance is passed,
advance the tube a little more then hold on. (at
about 15 cm) - Turn the tube gently while have the patient
breathe deeply, stop at the point of the largest
air passage.
22Two points of high resistance
1st
2nd
1 st between turbinate and nasal septum. 2 nd
turning into oropharynx
23Advancing the Scope
- Always keep the black in the center of the field.
(Esp. in distorted anatomy) - Identify the epiglottis.
- Pass beneath the epiglottis then bend the scope
upwards a little to make the opening of glottis
in the center of the field. - Bingo!
24Blood the Most Unwanted
- Be gentle in passing the tube through the
nasopharynx ! - Suction not always works well, usually quite
unsatisfactory. - Slightly back-up position, have the patient
swallowing the blood. - Advance the scope blindly esophagus is often
entered (which means the midline position of the
scope is secured), then withdraw slowly. Once the
scope slips out of esophagus, glottic opening is
hopefully in view.
25The Oral Approach
- A more curved pathway compared with nasal passage
- Less convenient in distorted anatomy
- Prone to deviate from midline position (an
intubating airway is helpful.) - Easy to cause fiberoscope damage
- Can be done at sitting position
26The Oral Approach
- An oral bite is a must unless very good topical
anesthesia (which is a rarity.) - Advance the tip of the scope till the posterior
part of the tongue base then bend downwards
nearly 90 epiglottis will appear in view. - Advance between epiglottis and posterior wall of
larynx. Glottic opening would be found.
27Causes of Failed Fiberoptic Intubation
- Lack of expertise (most common)
- Secretion and blood
- Fogging of lenses
- Poor topical anesthesia
- Distorted anatomy
- Fiberoscope malfunction
- Inadvertent passage of fiberoscope through
Murphys eye
28Practice of Fiberoptic Intubation on Healthy
Patients More Often !
29Retrograde Intubation
30The Three Tenors good for the concert, disaster
for the OR.
31Laryngeal Mask Airway (LMA)
- Sizes
- 1 lt6.5 kg 2-5 ml 3.5
- 2 6.5-20 kg 10 ml 4.5
- 2 1/2 20-30 kg 14 ml 5.0
- 3 30-60 kg 20 ml 6.0
(cuffed) - 4 60 kg 30 ml 6.5
(cuffed) - 5 gt70 kg
32Does the Size Matter?
- It does in routine use.
- It dose not in difficult airway management.
- In patients with macroglossia, limited mouth
opening, poor dentition, enlarged adenoid tissue,
insertion of LMA is perceivably difficult the
use of LMA in these cases should be reconsidered. - A smaller size than recommended may help.
33(No Transcript)
34The Technique of Insertion (I)
- Deflate the mask while pressing the bowl of the
LMA against a flat surface. - Lubricate the posterior surface of the LMA.
- After induction, patients head is slightly
extended. - Insert the LMA into patients mouth, pressing the
back firmly against the hard palate.
35The Technique of Insertion (II)
- LMA should be seen to flatten against the palate.
- Push the LMA further while firmly pressing
against the palate. - Once pass the tongue, the LMA can be advanced
without resistance. - Inflate the cuff, then check the ETCO2 after
several manual ventilation. - Secure LMA with tape, with the black line facing
the nose.
36Keypoints for Successful LMA Insertion
- Practice and expertise
- Choice of correct size
- Proper patient positioning
- Adherence to correct technique
- Adequate depth of anesthesia
37Removal of LMA
- At deep or light level of anesthesia.
- Do not suction inside the LMA!
38Dont treat LMA like an ET tube!
- Dont push over the posterior pharyngeal wall!
- Dont suction inside the LMA!
39After LMA Insertion
- Awake the patient and cancel operation.
- Continue the operation with LMA.
- Fiberoscope intubation with LMA (then change to a
bigger ET tube).
40Contraindications of LMA
- Patients at the risk of aspiration
- Patients with poor pulmonary compliance
- Pharyngeal pathology
41Light Wand
- Et tube is attached to the light wand after
lubrication both inside and outside the tube. - A 90-degree bend is made at the distal end of the
tube. - After induction and mask ventilation is assured,
put the patient in neutral position with the neck
slightly extended. - Open the mouth and apply light wand until light
is seen in thyroid cartilage advance the tube.
42Problem Shooting in Light Wand
- No light is seen in the neck
- Light malfunction
- Increase the length of the bent end
- Light is seen in pyriform sinus
- Withdraw-reapply policy
43Admonition
- LMA and lightwand are basically used for
difficult intubation after induction and mask
ventilation is assured. - In case of difficult mask ventilation, LMA can be
tried in a very short time shift to cricothyroid
membrane puncture ASAP if LMA fails after
several attempts. Lightwand is generally not
desirable in difficult mask ventilation. - Rethink and take great care when use LMA and
lightwand in limited mouth opening!
44Tube Exchanger
45(No Transcript)
46Have an Algorithm of Yourself!
47(No Transcript)
48How to Recognize Esophageal Intubation?
49CO2 waveform in a 10 y/o boy after intubation.
Breathing sound clear bilaterally
Anesthesia Analgesia 66481, 1987
50CO2 waveform during tracheal and esophageal
intubation.
Anesthesia Analgesia 73333, 1991
51CO2 waveform during tracheal and esophageal
intubation afte addition of a carbonated beverage
into stomach.
Anesthesia Analgesia 73333, 1991
52Recognition of Tracheal Intubation
- Gold standard ETCO2
- Normal capnography indicating tracheal
intubation - CO2 may appear after several manual ventilations.
(From alveoli to the machine) - CO2 level increases to normal range and persists
after at least 5 manual ventilations.
53Pitfalls of Auscultation
- In the absence of ETCO2, stomach should be
checked first! - In case of esophageal intubation, chest
auscultation may reveal no obvious breathing
sound (mimicking bronchospasm) or a false typical
bilateral symmetrical breathing sound transuded
from stomach.
54How long does it take for a patient with an
unnoticed esophageal intubation to become
cyanotic / low SpO2?
55Case Presentation
- 42 y/o male, 87kg, severe burn over neck and
facial area with inhalation injury. Mechanical
ventilation is expected. You are the
anesthesiologist who is consulted to the burn ICU
for tracheal re-intubation because a suspected
cuff rupture. At arrival in ICU, only an intern
and a nurse is on the site. - What equipment will you take with you?
- What do you ask them to prepare for you?
- How to differentiate between esophageal/ tracheal
intubation on the site?
56Preparation for Intubation outside OR
- MA SALT
- Mask
- Ambu bag
- Suction
- Airway
- Laryngoscope
- Tube
57How to Differentiate Esophageal Intubation
outside the OR?
- Make good use of the tube exchanger!
58GOOD LUCK!