Airway Management

Dr. Paul Labana
Emergency Medicine Consultant
12th February 2014
Overview

 Case presentation
 Assessment
 Clinical features

 Decision making algorithms
 Equipment used
 35 yr male is t/f to TWH with 5% PT burns to face, neck,
anterior chest after methylated spirits explodes from fire

 PMHx – Type I DM, hypercholesterolaemia, hypertension,
smoker, occasional EtOH
 Coversyl +, Amlodipine, Atorvastatin, Protophane, Actrapid
 Allergic to penicillin
 On examination: A, B, C currently stable pain under control,
covered in dressings with only nose showing, blisters/swelling
around lips/oropharynx
 Starts to complain of SOB – vitals OK on high flow oxygen
What would you do next?
 O/E facial swelling (but not in mouth), blisters on lips, nasal
hair singed
 Decision for definitive airway
 Pre-ox, cricoid pressure, propofol, suxamethonium
 Initially grade 2 view with McCoy blade + stylet
 ETT dislodged on removing stylet (paraffin all over
face/gloves making jaw thrust impossible)
 Bag & Mask ventilation
 Sux. wearing off, biting through guedel, desat 55% at lowest
 Further propofol, sux – Fastrach inserted #5 but big leak
 Replaced with classic – good ventilation
 Pt. became bradycardic – atropine 300 mcg
 Further attempts at ETT with swollen tongue, eventually
intubated as confirmed by ETCO2
Progress
 Continued to improve over next 5 days
 Successfully extubated with nil stridor and good ABG’s
 D/C to burns unit
 Later d/c and was well
General Principles of Airway Management
Airway Management
 Aims of management

 Maintain oxygenation, prevent hypercarbia
 Minimise airway trauma (i.e. minimal
instrumentation)

 3 main scenarios

 Anticipated difficult airway e.g. burns
 Unanticipated difficult airway
 Facial/neck trauma
Methods of assessment
 Anaesthetic history (if at all available)

 History
 Previous difficult intubation/ventilation
 Congenital syndromes
 Down’s syndrome, large tongue, Atlanto-axial
instability
 Nasal polyps, neck and TMJ problems, loose teeth
 Examination
 Facial hair
 Teeth: protruding or long upper incisors, prominent
overbite
 Mouth opening (need at least 3-4 cm between incisors)
 High arched, narrow palate
 Mandibular protrusion (upper lip bite)
 Neck mobility and masses
 Thyromental distance (>6cm normal)
Examination
 General Habitus











 Ethnic differences: anterior larynx, small jaw, protruberant teeth
 Pregnant: Large breasts, mucosal hypervascularity, reduced oxygen reservoir with risk
of desaturation
 Congenital syndromes: Downs’ syndrome, Goldenhaar, Pierre-Robin, Achondroplasia
 Orofacial trauma - (patient in C-spine collar?)
Nose
 Nasal polyps, deviated septum, hypervascularity in pregnancy
Mouth
 Small or restricted mouth opening, restricting laryngoscope passage
Teeth
 Protruberant incisors, loose teeth (potential airway obstruction if knocked out)
Tongue
 Macroglossia (Down’s Syndrome, Acromegaly)
Jaw (incl. TMJ)
 Small or recessive jaw, previous TMJ surgery causing restriction may impede
laryngoscopic view
Neck
 Bullneck, previous surgery/tracheostomy
 Reduced ROM: Ankylosing Spondylitis, previous fusion, rheumatoid instability
Environment
 Lack of equipment, skilled assistant
Relative Tongue/Pharyngeal size


Modified Mallampati classification gives variable
prediction of airway difficulty (rarely possible in
emergency setting)









I: Soft Palate, Fauces, Uvula, Ant + Post pillars
II: Soft palate, Fauces, Uvula
III: Soft palate, base of uvula
IV: Hard palate only

Performed with patient seated, head in neutral position,
mouth open to widest extent and tongue maximally
protruded without phonation
Correlation with Cormack-Lehane grading:




Class I: Grade I view 99-100% of the time
Class IV: Grade III or IV view 100% of the time
Class II and III are poor predictors
The Mallampati classification is a simple scoring system that relates the amount of
mouth opening to the size of the tongue, and provides an estimate of space
available for oral intubation by direct laryngoscopy. According to the Mallampati
scale, class one is present when the soft palate, uvula, and pillars are visible, class
two when the soft palate and uvula are visible, class three when the soft palate and
only the base of the uvula are visible, and class four when only the hard palate is
visible.
The Cormack-Lehane system for grading
laryngoscopic view at intubation
Difficult ventilation
Pregnant
 Increased breast tissue with reduced chest
compliance
 Obese
 As above, plus increased pharyngeal tissue with
increased upper airway resistance
 OSA / Snorers
 Beard
 Difficult to achieve seal with mask
 Edentulous
 Difficult to achieve seal with mask

Neck mobility and correct positioning

1. Bad : neutral position

2. Better : C6/C7 flexion

3. Best : Flexion at C6/C7
Extension at C1/C2 (~ 35º)
“Sniffing the morning air…”
Complications of difficult airway access










Hypoxaemia
Soft tissue injury of the airway
Increased gastric aspiration/regurgitation
risk
Haemodynamic stress of repeated
laryngoscopic stress attempts
Unnecessary tracheostomy
Tooth damage
Facial/Neck Trauma & Burns
 Ensure senior anaesthetic/surgical help present
 Early consideration of intubation/surgical airway essential
 Childhood infections causing partial obstruction generally approached
via gentle inhalational induction therefore call anaesthetics a.s.a.p.
 Can return to spontaneous breathing if laryngoscopic view poor, or
offer option of FOB (bearing in mind it may occlude already narrow
lumen)
 In cases of marked deformed anatomy, tracheostomy is generally the
definitive management
 Open vs percutaneous dilational: No major difference in outcome,
PDT associated with reduced risk of pneumomediastinum/bleeding
 May be performed under local anaesthetic (ketamine has also been
described)
LEMON
 L ook (facies, anatomy, obesity etc.)
 E valuate 3-3-2 (see below)

 M allampati
 O bstruction (mass, infection, SOL)
 N eck mobility (“sniffing morning air”)
Preparation for intubation

P repare patient & drugs & P ositioning
E nd-tidal CO2
M ask (& bag connected to O2 AND ON)
A djuncts (LMA/Guedel/Nasopharyngeal)
I ntroducer
L aryngoscope
S uction (turned on at head of bed)
Failed Intubation
Laryngoscopes



Macintosh (standard used on airway trolleys)
McCoy






Kessel




Modified Macintosh blade with increased handle-blade angle (110˚): easier
insertion in large-breasted (pregnant) women

Miller





Levered mobile tip allowing elevation of epiglottis
Potentially reduces C-L grade by one
Useful in cervical collar patients, anterior larynx

Straight blade with curved tip for elevating epiglottis
Thinner profile: easier insertion in small-mouth opening pts

Huffman


Macintosh blade with 30 or 80˚ refractive prism towards larynx: allows
indirect laryngoscopy
Intubation Aides


Gum elastic bougie (Eschmann tracheal tube introducer)
 60cm, 15F (adults)/10F (children), Coude tip. Introduced in the 1970’s
 Portex reusable bougies most common. Disposable available but
reported to have reduced success with intubation (?due to less
malleable texture)
 Used in conjunction with laryngoscope to facilitate ETT passage where
laryngeal inlet is incompletely visualised (or can be inserted blindly)
 Advantages are
 Longer compared with stylets


Malleable, angled tip - ideally at 60˚ to capture tracheal
“clicks”

Flexible yet firm enough to have ETT railroaded over it
Signs that bougie is endotracheal (therefore safe to railroad ETT)








“Clicks” from tracheal rings
Hold-up/Resistance at ~40cm (within bronchial tree)
Coughing
Intubation Aides 2
 Airway exchange catheters
 Functions as bougie, but with central lumen allowing
ongoing oxygenation between intubation attempts
 Internal diameter varies between 3.7mm (Cook exchange
catheters) to 4.7mm (Aintree airway catheters)
 NICE paper demonstrating use in conjunction with

LMA and fibreoptic bronchoscope:



Low-skill fibreoptic intubation: use of the Aintree catheter with the classic LMA.
Anaesthesia 2005; 60: 915-920

Stylet


Malleable, single use stylets used to shape ETT, allowing for easier

passage into anterior larynxes

BURP/2 person intubation
Laryngeal Mask Airway









Most are disposable
Once inserted, the mask is bounded by:
 Tip at level of inferior constrictor
 Sides abutting piriform fossae
 Top against base of tongue
Provides airway support rather than definitive airway
 Valuable tool in rescue “can’t intubate, can’t mask ventilate” situations
Serves as a conduit for endotracheal intubation
 Theoretically #4 can fit a 5.5 ETT, but clumsy fit at best
 Narrowest point is at LMA connector - ETT cuff may be torn here
 Length of LMA tube may lead to improper depth of ETT placement
 Very difficult to remove LMA once ETT is placed
 Gum-elastic bougie/Fibreoptic bronchoscope may be fed down lumen to
facilitate endotracheal intubation and confirm position
Bronchoscopic port connector allows simultaneous ventilation & FOB
Cook Kit (Seldinger technique)






Seldinger technique safer than blind
approach
Aspirate air with the needle and syringe to
check placement, cut with scalpel
Remove syringe, insert wire into
needle, remove needle
Thread dilator with airway already loaded
onto wire
Remove wire
Needle cricothyroidotomy

 Oxygenation NOT ventilation

 Use 14 g cannula with syringe attached, once
aspirating air, insert sheath and remove needle
 Connect a 3 way valve to sheath and to oxygen
tubing
 15 L/min oxygen for 1 sec followed by 4 secs
expiration phase
 Approximately 45 mins to get definitive
airway




Cricothyroid membrane between thyroid and
cricoid cartilage
Locate hyoid with thumb & index finger and
middle finger will fall on correct area (1-1.5 cm
below)
Standard Surgical Airway








Equipment always available BUT need
most senior help available
Vertical incision in skin of neck
Transverse incision of cricothyroid
membrane
Artery forceps/finger to open airway
Insert cuffed ETT 6.0 into trachea
Surgical Airway
Questions ???

Airway management in the Emergency Department for Trainees

  • 1.
    Airway Management Dr. PaulLabana Emergency Medicine Consultant 12th February 2014
  • 2.
    Overview  Case presentation Assessment  Clinical features  Decision making algorithms  Equipment used
  • 3.
     35 yrmale is t/f to TWH with 5% PT burns to face, neck, anterior chest after methylated spirits explodes from fire  PMHx – Type I DM, hypercholesterolaemia, hypertension, smoker, occasional EtOH  Coversyl +, Amlodipine, Atorvastatin, Protophane, Actrapid  Allergic to penicillin  On examination: A, B, C currently stable pain under control, covered in dressings with only nose showing, blisters/swelling around lips/oropharynx  Starts to complain of SOB – vitals OK on high flow oxygen
  • 4.
  • 5.
     O/E facialswelling (but not in mouth), blisters on lips, nasal hair singed  Decision for definitive airway  Pre-ox, cricoid pressure, propofol, suxamethonium  Initially grade 2 view with McCoy blade + stylet  ETT dislodged on removing stylet (paraffin all over face/gloves making jaw thrust impossible)  Bag & Mask ventilation  Sux. wearing off, biting through guedel, desat 55% at lowest  Further propofol, sux – Fastrach inserted #5 but big leak  Replaced with classic – good ventilation  Pt. became bradycardic – atropine 300 mcg  Further attempts at ETT with swollen tongue, eventually intubated as confirmed by ETCO2
  • 6.
    Progress  Continued toimprove over next 5 days  Successfully extubated with nil stridor and good ABG’s  D/C to burns unit  Later d/c and was well
  • 7.
    General Principles ofAirway Management
  • 8.
    Airway Management  Aimsof management  Maintain oxygenation, prevent hypercarbia  Minimise airway trauma (i.e. minimal instrumentation)  3 main scenarios  Anticipated difficult airway e.g. burns  Unanticipated difficult airway  Facial/neck trauma
  • 9.
    Methods of assessment Anaesthetic history (if at all available)  History  Previous difficult intubation/ventilation  Congenital syndromes  Down’s syndrome, large tongue, Atlanto-axial instability  Nasal polyps, neck and TMJ problems, loose teeth  Examination  Facial hair  Teeth: protruding or long upper incisors, prominent overbite  Mouth opening (need at least 3-4 cm between incisors)  High arched, narrow palate  Mandibular protrusion (upper lip bite)  Neck mobility and masses  Thyromental distance (>6cm normal)
  • 10.
    Examination  General Habitus        Ethnic differences: anterior larynx, small jaw, protruberant teeth  Pregnant: Large breasts, mucosal hypervascularity, reduced oxygen reservoir with risk of desaturation  Congenital syndromes: Downs’ syndrome, Goldenhaar, Pierre-Robin, Achondroplasia  Orofacial trauma - (patient in C-spine collar?) Nose  Nasal polyps, deviated septum, hypervascularity in pregnancy Mouth  Small or restricted mouth opening, restricting laryngoscope passage Teeth  Protruberant incisors, loose teeth (potential airway obstruction if knocked out) Tongue  Macroglossia (Down’s Syndrome, Acromegaly) Jaw (incl. TMJ)  Small or recessive jaw, previous TMJ surgery causing restriction may impede laryngoscopic view Neck  Bullneck, previous surgery/tracheostomy  Reduced ROM: Ankylosing Spondylitis, previous fusion, rheumatoid instability Environment  Lack of equipment, skilled assistant
  • 11.
    Relative Tongue/Pharyngeal size  ModifiedMallampati classification gives variable prediction of airway difficulty (rarely possible in emergency setting)       I: Soft Palate, Fauces, Uvula, Ant + Post pillars II: Soft palate, Fauces, Uvula III: Soft palate, base of uvula IV: Hard palate only Performed with patient seated, head in neutral position, mouth open to widest extent and tongue maximally protruded without phonation Correlation with Cormack-Lehane grading:    Class I: Grade I view 99-100% of the time Class IV: Grade III or IV view 100% of the time Class II and III are poor predictors
  • 12.
    The Mallampati classificationis a simple scoring system that relates the amount of mouth opening to the size of the tongue, and provides an estimate of space available for oral intubation by direct laryngoscopy. According to the Mallampati scale, class one is present when the soft palate, uvula, and pillars are visible, class two when the soft palate and uvula are visible, class three when the soft palate and only the base of the uvula are visible, and class four when only the hard palate is visible.
  • 13.
    The Cormack-Lehane systemfor grading laryngoscopic view at intubation
  • 14.
    Difficult ventilation Pregnant  Increasedbreast tissue with reduced chest compliance  Obese  As above, plus increased pharyngeal tissue with increased upper airway resistance  OSA / Snorers  Beard  Difficult to achieve seal with mask  Edentulous  Difficult to achieve seal with mask 
  • 15.
    Neck mobility andcorrect positioning 1. Bad : neutral position 2. Better : C6/C7 flexion 3. Best : Flexion at C6/C7 Extension at C1/C2 (~ 35º) “Sniffing the morning air…”
  • 16.
    Complications of difficultairway access       Hypoxaemia Soft tissue injury of the airway Increased gastric aspiration/regurgitation risk Haemodynamic stress of repeated laryngoscopic stress attempts Unnecessary tracheostomy Tooth damage
  • 17.
    Facial/Neck Trauma &Burns  Ensure senior anaesthetic/surgical help present  Early consideration of intubation/surgical airway essential  Childhood infections causing partial obstruction generally approached via gentle inhalational induction therefore call anaesthetics a.s.a.p.  Can return to spontaneous breathing if laryngoscopic view poor, or offer option of FOB (bearing in mind it may occlude already narrow lumen)  In cases of marked deformed anatomy, tracheostomy is generally the definitive management  Open vs percutaneous dilational: No major difference in outcome, PDT associated with reduced risk of pneumomediastinum/bleeding  May be performed under local anaesthetic (ketamine has also been described)
  • 18.
    LEMON  L ook(facies, anatomy, obesity etc.)  E valuate 3-3-2 (see below)  M allampati  O bstruction (mass, infection, SOL)  N eck mobility (“sniffing morning air”)
  • 19.
    Preparation for intubation Prepare patient & drugs & P ositioning E nd-tidal CO2 M ask (& bag connected to O2 AND ON) A djuncts (LMA/Guedel/Nasopharyngeal) I ntroducer L aryngoscope S uction (turned on at head of bed)
  • 21.
  • 22.
    Laryngoscopes   Macintosh (standard usedon airway trolleys) McCoy     Kessel   Modified Macintosh blade with increased handle-blade angle (110˚): easier insertion in large-breasted (pregnant) women Miller    Levered mobile tip allowing elevation of epiglottis Potentially reduces C-L grade by one Useful in cervical collar patients, anterior larynx Straight blade with curved tip for elevating epiglottis Thinner profile: easier insertion in small-mouth opening pts Huffman  Macintosh blade with 30 or 80˚ refractive prism towards larynx: allows indirect laryngoscopy
  • 23.
    Intubation Aides  Gum elasticbougie (Eschmann tracheal tube introducer)  60cm, 15F (adults)/10F (children), Coude tip. Introduced in the 1970’s  Portex reusable bougies most common. Disposable available but reported to have reduced success with intubation (?due to less malleable texture)  Used in conjunction with laryngoscope to facilitate ETT passage where laryngeal inlet is incompletely visualised (or can be inserted blindly)  Advantages are  Longer compared with stylets  Malleable, angled tip - ideally at 60˚ to capture tracheal “clicks” Flexible yet firm enough to have ETT railroaded over it Signs that bougie is endotracheal (therefore safe to railroad ETT)      “Clicks” from tracheal rings Hold-up/Resistance at ~40cm (within bronchial tree) Coughing
  • 24.
    Intubation Aides 2 Airway exchange catheters  Functions as bougie, but with central lumen allowing ongoing oxygenation between intubation attempts  Internal diameter varies between 3.7mm (Cook exchange catheters) to 4.7mm (Aintree airway catheters)  NICE paper demonstrating use in conjunction with LMA and fibreoptic bronchoscope:  Low-skill fibreoptic intubation: use of the Aintree catheter with the classic LMA. Anaesthesia 2005; 60: 915-920 Stylet  Malleable, single use stylets used to shape ETT, allowing for easier passage into anterior larynxes BURP/2 person intubation
  • 25.
    Laryngeal Mask Airway      Mostare disposable Once inserted, the mask is bounded by:  Tip at level of inferior constrictor  Sides abutting piriform fossae  Top against base of tongue Provides airway support rather than definitive airway  Valuable tool in rescue “can’t intubate, can’t mask ventilate” situations Serves as a conduit for endotracheal intubation  Theoretically #4 can fit a 5.5 ETT, but clumsy fit at best  Narrowest point is at LMA connector - ETT cuff may be torn here  Length of LMA tube may lead to improper depth of ETT placement  Very difficult to remove LMA once ETT is placed  Gum-elastic bougie/Fibreoptic bronchoscope may be fed down lumen to facilitate endotracheal intubation and confirm position Bronchoscopic port connector allows simultaneous ventilation & FOB
  • 26.
    Cook Kit (Seldingertechnique)      Seldinger technique safer than blind approach Aspirate air with the needle and syringe to check placement, cut with scalpel Remove syringe, insert wire into needle, remove needle Thread dilator with airway already loaded onto wire Remove wire
  • 28.
    Needle cricothyroidotomy  OxygenationNOT ventilation  Use 14 g cannula with syringe attached, once aspirating air, insert sheath and remove needle  Connect a 3 way valve to sheath and to oxygen tubing  15 L/min oxygen for 1 sec followed by 4 secs expiration phase  Approximately 45 mins to get definitive airway
  • 29.
      Cricothyroid membrane betweenthyroid and cricoid cartilage Locate hyoid with thumb & index finger and middle finger will fall on correct area (1-1.5 cm below)
  • 30.
    Standard Surgical Airway      Equipmentalways available BUT need most senior help available Vertical incision in skin of neck Transverse incision of cricothyroid membrane Artery forceps/finger to open airway Insert cuffed ETT 6.0 into trachea
  • 31.
  • 33.