Title: AIRWAY MANAGEMENT IN PATIENTS WITH UNSTABLE CERVICAL SPINES STRATEGIES AND TECHNIQUES
1AIRWAY MANAGEMENT IN PATIENTS WITH UNSTABLE
CERVICAL SPINESSTRATEGIES AND TECHNIQUES
- Brad Hindman, M.D.
- Department of Anesthesia
- University of Iowa, College of Medicine
2Endotracheal Intubation in Patients With Cervical
Spine Instability
- Secure airway without causing/worsening
neurologic injury - These patients are often a difficult intubation
- Disease process
- Methods to stabilize cervical spine
3Motion Force During Conventional Direct
Laryngoscopy IntubationNormal Spine
4Normal SpineCervical Spine Motion during Direct
Laryngoscopy/Intubation
5Normal SpineLifting Force during Direct
Laryngoscopy/Intubation a,b
6SummaryNormal Cervical Spines
- Cervical motion may be reduced by limiting
glottic exposure - Poor glottic view could pose risk with unstable
cervical spines - Too much force across unstable segments
7Motion ForceConventional Direct Laryngoscopy
IntubationUnstable Spine
8Unstable Cervical Spine
- Moves abnormally with motion/force of
laryngoscopy - Where pathologic motion occurs depends on
- Specific location nature of instability
- Force applied across unstable segment
9Unstable SpineO-C1-C2 Complex
- Laxity of Transverse Ligament (Rheumatoid
Arthritis, Down Syndrome) - Flexion Odontoid moves posteriorly towards cord
- Intubation (extension) Theoretically, not at
risk - Abnormal odontoid and/or O-C1-C2 articulations
- Flexion/Extension C1 subluxes on C2, compressing
cord - Intubation (extension) AT RISK
- Combined bony ligamentous abnormalities - ?
10Unstable SpineSub-axial Segments (C3-C7)Spine
Movement during Laryngoscopy/Intubation
11SummaryUnstable Cervical Spine
- Difficult to predict net spine motion during
laryngoscopy - When cervical spine instability present
- Minimize force applied across unstable segments
- Minimize cervical spine motion
- Maintain neck in neutral position
12Effects of External Cervical SpineStabilization
MethodsNormal Spine
13Normal SpineCollars and Manual In-Line
Stabilization (MILS)
- Concept Prevent spine movement during intubation
- Majernick TG Ann Emerg Med 1986 15417
- 16 normal subjects
- Collars did not reduce spine motion
- MILS did appear to reduce spine motion
14Normal SpineEffect of MILS during Direct
Laryngoscopy Intubation
15Effects of External Cervical SpineStabilization
MethodsUnstable Spine
16Unstable SpineEffect of Stabilization
- Aprahamian C Ann Emerg Med 1984 13584
- 1 cadaver complete C5-C6 ligamentous instability
- Rigid Collar did not appear to affect spine
movement - Donaldson WF Spine 1993 182020
- 5 cadavers incomplete C5-C6 ligamentous
instability - Head stabilization may have ? subluxation
angulation - Lennarson PJ J Neurosurg (Spine 2) 2000 92201
- 16 cadavers incomplete C4-C5 ligamentous
instability - MILS did not prevent abnormal flexion
17Unstable SpineComplete ligamentous laxity at
C4-C5a
18Unstable SpineAxial Traction
- Can result in severe distraction
- Bivins HG Ann Emerg Med 1988 1725
- Donaldson WF 3rd Spine 1993 182020
- Axial traction is to be avoided during
intubation, unless...
19Unstable SpineEffect of MILS with O-C1-C2
Instability
20SummaryExternal Stabilization Maneuvers Spine
MovementDuring Laryngoscopy and Intubation
- Axial Traction
- O-C2 Probably dangerous
- C3-C7 Probably dangerous
- Cervical Collars
- O-C2 ?
- C3-C7 No indication of benefit
- MILS
- O-C2 May be of benefit, maybe not
- C3-C7 May be of benefit, maybe not
- Nevertheless, it is the standard of care
21Method of Manual In-Line Stabilization
(MILS)During Conventional Direct Laryngoscopy
- Patient supine, head flat on table in neutral
position - Assistant
- Grasps both mastoid processes with fingertips
- Cup occiput in hands without applying axial
traction - Anterior portion of cervical spine collar removed
- Allows maximal mouth opening
- Expose anterior neck (cricoid pressure,
retrograde wire, or surgical airway)
22Method of MILS, continued
- Preoxygenation ( cricoid pressure if full
stomach) - Sedatives/anesthetics paralytics as indicated
- Assistant applies force(s) equal opposite to
those of DL to keep the head/neck in neutral
position
23By limiting extension at O-C2MILS often worsens
glottic view with conventional DLGlottic View
with Standard Head Neck Position vs. MILSa
24MILS Conventional Direct Laryngoscopy
- 10 risk of not seeing glottis
- Lifting harder may not be advisable
- Airway aids (bougie, light wand, fiberoscope)
- Alternatives to Conventional Direct Laryngoscopy
- Bullard, WuScope, Intubating LMA
25Clinical Scenarios General Approachesto
Endotracheal IntubationEmergent Intubation with
Traumatic Cervical Spine Injury
26Emergent Intubation and C-Spine
Trauma/InstabilityThe Cervical Spine in the
Setting of Trauma
- 2-4 of blunt trauma patients have C-spine
fx/dislocations - Cluster around C1-C2 C5-C6
- 70 have major associated injuries
- 50 have neurologic signs/symptoms
- 25-50 require intubation within 24 h
- Before complete/definitive C-spine evaluation
- In presence of known instability
- Effect of DL/intubation difficult to predict
27Emergent Intubation and C-Spine
Trauma/InstabilityNeurologic Injury from
Conventional DL IntubationLow but Real
- Hastings RH Anesthesiology 1993 78580
- Unrecognized fx at C6-C7
- Muckart DJJ Anesthesiology 1997 87418
- 2 patients Unrecognized fxs at C2 C6
- Redl G Anesthesiology 1998 891262
- Unrecognized C2 instability
28Emergent Intubation and C-Spine
Trauma/InstabilityAdvanced Trauma Life Support
(ATLS) Guidelines-1980s
- Blind nasotracheal intubation for emergent
intubation - (n1) Aprahamian C Ann Emerg Med 1984 13584
- (n7) Bivins HG Ann Emerg Med 1988 1725
- Problems
- Often not easy
- Often not fast
- Often not successful
- Sometimes contraindicated (basilar- mid-face fx)
29Emergent Intubation and C-Spine
Trauma/InstabilityIntubation Methods In Patients
with Acute Cervical Spine Injury
30Emergent Intubation and C-Spine
Trauma/InstabilityRisk of Neurologic Injury
- Conventional Direct Laryngoscopy MILS
(anesthesia, paralysis) - 0/374 95 confidence 0-1
- Awake Nasotracheal Intubation
- 0/240 95 confidence 0-2
31Emergent Intubation and C-Spine
Trauma/InstabilityAdvanced Trauma Life Support
(ATLS) Guidelines-NOW
The most important determinant of whether to
proceed with orotracheal or nasotracheal
intubation is the experience of the doctor. Both
techniques are safe and effective when performed
properly. If orotracheal intubation is
chosen the two-person technique with in-line
immobilization should be used. - ATLS Student
Course Manual, 6th Edition, 1997
32Emergent Intubation and C-Spine
Trauma-InstabilityConventional DL Intubation
with MILS/Trauma
- Failed intubation reported 2-10
- MILS can limit glottic visualization
- Blood secretions
- Altered anatomy (prevertebral swelling)
- Difficult Airway algorithm (Caplan RA
Anesthesiology 1993 78597)
33Clinical Scenarios General Approachesto
Endotracheal IntubationNON-Emergent Intubation
with Cervical Spine Instability
34NON-Emergent Intubation with Cervical Spine
InstabilityRosenblatt WH Anesth Analg 1998
87153
35NON-Emergent Intubation with Cervical Spine
InstabilityAirway Anesthesia
- Supraglottic (Superior Laryngeal Nerve)
- Internal br. Sensory Pharynx to false cords
- External br. Motor to cricothyroid muscle
- Blockade Thyrohyoid membrane or pyriform fossa
- Subglottic (Recurrent Laryngeal Nerve)
- Sensory True vocal cords to trachea
- Motor Intrinsic muscles of larynx
- Blockade Transcricoid injection of local
anesthetic - Combined (Topical)
- Inhalation f nebulized local anesthetic
36NON-Emergent Intubation with Cervical Spine
InstabilityAirway Anesthesia
- Nasal Mucosae (Trigeminal)
- Anesthesia and vasoconstriction
- 4 cocaine or 3-4 lidocaine/0.25-1.00
phenylephrine - Oral/Gag (Glossopharyngeal)
- Lingual br. Posterior 1/3rd of tongue
- Blockade Palatoglossal arch (injection or
topical)
37Airway Anesthesia Topical vs. BlocksReasoner
DK J Neurosurg Anesth 1995 794
38NON-Emergent Intubation, FiberopticsDifficulties
Encountered during Elective Fiberoptic
Intubation in Patients with Cervical Spine
Diseasea,b,c,d
39NON-Emergent Intubation, FiberopticsEndotracheal
tube catching on Glottic Structuresa
a. Katsnelson T Anesthesiology 1992 76151
40NON-Emergent Intubation, FiberopticsEndotracheal
tube catching on Glottic Structures
41NON-Emergent Intubation, FiberopticEndotracheal
tube catching on Glottic Structures
- Rotate tube counterclockwise during advancement
- Pull tongue forward during advancement
- Patient persistence
42NON-Emergent Intubation with Cervical Spine
InstabilityThe Bullard Laryngoscope
43NON-Emergent Intubation with Cervical
InstabilityThe Bullard Laryngoscope
- Potential Advantages
- Can be faster than fiberoptics
- Neck can be maintained in neutral position
- Better glottic visualization with MILS
44NON-Emergent Intubation with Cervical Spine
InstabilityConventional Laryngoscopy vs. Bullarda
45NON-Emergent Intubation with Cervical Spine
InstabilityThe Bullard Laryngoscope
- Notes of Caution
- Significant learning curve
- Not evaluated in patients with unstable spines
- Successful intubation not a sure thing
- 15 failure (MacQuarrie K Can J Anesth 1999
46760)
46NON-Emergent Intubation with Cervical Spine
InstabilityThe WuScope
47NON-Emergent Intubation with Cervical Spine
Instability WuScope MILS vs. Conventional DL
MILSa
48NON-Emergent Intubation with Cervical Spine
InstabilityThe WuScope
- Potential Advantages
- Neck can be maintained in neutral position
- Better glottic visualization with MILS
- Notes of Caution
- Learning Curve
- Not evaluated in patients with unstable spines
- Not a sure thing
49NON-Emergent Intubation with Cervical Spine
InstabilityThe Intubating LMA (ILMA)
50NON-Emergent Intubation with Cervical Spine
InstabilityThe ILMA
- Can be inserted with head neck neutral
- Designed to allow rapid blind orotracheal
intubation - Fiberoptic guided intubation also possible
- Case reports of use in patients with unstable
spinesa,b - a. Schuschnig C Anaesthesia 1999 54793
- b. Wong JK J Clin Anesth 1999 11346
51NON-Emergent Intubation with Cervical Spine
InstabilityThe ILMA
- Patients in Cervical Collarsa
- Placement generally difficult
- Ventilation poor 40 blind intubation success
20 - Patients with Cervical Spine Disease (25
unstable)b - ?2 attempts to place 25
- Blind intubation success 63 esophageal
intubation 8 - Patients with Cervical Spine Disease (15
unstable)c - ?2 attempts to place 45
- C2-C5 displaced posteriorly 1.5-3.0 of flexion
- a. Wakeling HG Br J Anaesth 2000 84254
- b. Nakazawa K Anesth Analg 1999 891319
- c. Kihara S Anesth Analg 2000 91195
52NON-Emergent Intubation with Cervical Spine
InstabilityThe ILMA
- Cadavers with Stable Necksa
- ILMA Insertion/adjustment 200-400 cm H2O
pressure on C2-C3 - C3 displaced 1-3 mm
- Cadavers with Unstable Necks (posterior C3)b
- ILMA 1.71.3 mm post. displacement
- Conventional DL 2.61.6 mm post. displacement
- Combitube placement 3.21.6 mm post.
displacement - Nasal Fiberoptic 0.10.7 mm post. displacement
- a. Keller C Anesth Analg 1999891296
- b. Brimacombe J Anesth Analg 2000 911274
53NON-Emergent Intubation with Cervical Spine
InstabilityThe ILMA
- Notes of Caution
- Multiple attempts to correctly place often
necessary - Relatively low success rate with blind intubation
- High pressure on C2-C3, risk of spine displacement