Vanessa Fludder Worthing Anaesthetics Department The Difficult Airway Vanessa Fludder Worthing Anaesthetics Department

Causes of a difficult airway Small mouth opening Large tongue Dentition Big sticky out upper teeth Small lower jaw Immobility of head/neck/jaw Beard

The Difficult Airway - What exactly do we mean? Difficult Mask Ventilation Difficult Laryngoscopy Difficult Intubation All Three!

Causes of a difficult airway Congenital Infection Trauma Tumour Endocrine Body shape Degenerative Other (inhaled foreign body, anaphylaxis)

Congenital Down’s Syndrome Pierre Robin Treacher Collins Goldenhar’s Hurler’s Cleft Palate Marfan’s Klippel Feil

Down’s Syndrome Relatively large tongue Small mandible Atlanto-axial instability (20%) OSA is common Difficult intubation Smaller tube than predicted Atlanto axial instability = Poor muscle tone Ligamentous laxity Abnormal odontoid peg

Pierre Robin Severe micrognathia Posterior prolapse of tongue (small mandible) Posterior prolapse of tongue Difficult intubation Breathe better prone or on side May need tracheostomy

Goldenhar’s Facial Asymmetry Difficult intubation

Hurler’s Difficult intubation Connective Tissue disorder Mucopolysaccharidosis Abnormal airway anatomy Difficult intubation Also have dwarfism, cardiac failure

Infection Epiglottitis Croup Tonsilitis Tonsilar/Peritonsilar abcesses Dental abcess Ludwig’s Angina Tetanus Distortion of anatomy Narrowed airway Lung soiling if ruptures

Epiglottitis Haemophilus influenzae type B Adrenaline, heliox and steroids may help Gas induction sevo in 100% oxygen

NB don’t do X-ray!

Ludwig’s Angina

Tracheostomy – Gold Standard? Distorted anatomy, swollen tissue. Inability of patient to lie flat. Mediastinal spread of infection Aspiration of pus Recommended when retropharyngeal space is involved (CT scan)

Awake Fibre-optic Intubation May be more difficult due to copious secretions which cannot be swallowed Very important to avoid airway irritation and laryngeal spasm Probably the safest overall technique

Tetanus

Trauma C-spine injury Facial trauma Facial Burns Inhalational injury Post head/neck surgery/radiotherapy Inhaled foreign body Swelling, likely to get worse before better! Distortion of normal anatomy Hard collar Vision obscured by blood Post surgery or radiotherapy – scarring, immobility, relatively fixed.

C-spine injury Management Stable or Unstable? Elective Most likely patient will be in a hard collar Cannot move neck Associated injuries Management Elective Awake fibre-optic intubation Emergency RSI Remove collar if need to No evidence of damage to neck by intubation

Facial Burns Oedema worsens rapidly and may increase in 1st 24hrs Consider intubation if Soot in nostrils or in mouth Burns to face Do RSI, early rather than late, and don’t cut ETT

Inhalational Injury Airway oedema and obstruction Lung damage – ARDS Consider intubation if Voice changes Carboxyhaemoglobin levels > 15% CXR ranges Deteriorating ABGs

Inhaled foreign body Tend to be young Object may not be radio-opaque May push object further down by IPPV Dex/Adren to reduce swelling Inhalational induction ENT surgeon Ventilating rigid bronchoscope

Tumours

Airway tumours Pharyngeal Supraglottic Glottic Subglottic Check nasendoscopy pictures Look at CT scans Discuss with surgeon Change in voice Difficulty breathing Difficulty swallowing Stridor

Airway Tumours Supra-glottic Sub-glottic Cricothyroid cannula FOI asleep or awake Sub-glottic Laryngoscopy usually OK Will need smaller ETT

Endocrine Diabetes Mellitis Acromegally Thyroid Goitre

Diabetes Mellitis One third of IDDMs have a difficult airway! ? Due to glycosylation of tissue proteins Limited joint mobility Limited atlanto-occipital movement (Prayer sign)

Acromegally Enlarged facial features (Mask Ventilation can be difficult) Overgrowth of soft tissue in airway Enlarged tongue Enlarged epiglottis Smaller glottic aperture

Goitre

Degenerative/Autoimmune Ankylosing Spondylitis Rheumatoid Arthritis Scleroderma

Ankylosing Spondylitis Decreased mobility of whole spine Fixed flexion deformity of head and neck Some have limited mouth opening too due to flexed position of head Consider Type and length of operation Risk of aspiration Possibility of regional anaesthetic May not have a problem with mask ventilation, or LMA FOI asleep or awake

Rheumatoid Arthritis TMJ ankylosis Limited c-spine movement Cricoarytenoid arthritis

What to do? ‘Keep in mind that the discomfort of an intubation or the deformity of a tracheostomy will be forgiven much more readily than an anoxic event that occurs during the chaos of an emergency airway crisis’ WW shockley

Body Shape Obesity Pregnancy Beards! Dentition Obesity – increased soft tissue, obscuring view More difficult to position More difficult to ventilate, less overall compliance Higher BMR, less Oxygen reserve Reduced FRC OSAS

Pregnancy Increased risk of aspiration Increased airway tissue oedema Friable mucous membranes – liable to bleed Enlarged Breasts Complicated by Increased BMR, and decreased FRC and oxygen reserve

Management of Pregnant Woman Avoid GA! Antacid and prokinetc (ranitidine + maxalon +/- Sodium citrate) Optimum positioning Good pre-oxygenation RSI Short handled blade Don’t panic!

Avoiding Airway Problems Correct Positioning Proper equipment and preparation Proper pre-op assessment Plans A, B, C, D Call for senior help 

Avoiding Airway Problems Avoid GA! Local infiltration Local block Regional block Avoid traumatising the airway (BCMDI) Glycopyrolate Emergency Drugs Pre-Oxygenate properly

Management Plan A If no risk of aspiration If mask ventilation predicted not to be difficult iv induction Check mask ventilation Direct laryngoscopy Limited gentle attempts (ABCD) Asleep FOI or LMA

Management Plan B Risk of aspiration deemed to be significant Awake FOI Glycopyrolate 200mcg 15 mins pre-op Co-phenylcaine to nostrils NIBP, ECG, SpO2 Oxygen (nasal cannula) Epidural catheter in working channel, SAYGO Prepare equipment and mount ETT B4 start

Awake cricothyroid cannula