Airway Obstruction
OVERVIEW
Airway obstruction can be incomplete or complete
- Complete obstruction of the upper airway occurs when there is inability to talk, cough or breath. Apnea and cyanosis are present and paradoxical respiration may be noted.
- Incomplete obstruction occurs when there is partial upper airway obstruction and ability to breath is maintained. Inspiratory stridor and increased work of breathing are the hallmarks.
Upper airway obstruction can be due to the following factors:
- luminal (e.g. foreign body)
- intramural (e.g. tumour, neuromuscular diseases)
- extramural (e.g. thyroid mass)
CAUSES
- Foreign body
- Infection
- Epiglottis
- Retropharyngeal abscess
- Bacterial tracheitis
- Ludwig’s angina
- Laryngotracheitis
- Diptheria
- Tetanus
- Immune
- Angioedema
- Anaphylaxis
- Tumor
- Trauma
- Neck hematoma, e.g. trauma, bleeding diathesis, anticoagulants
- laryngeal fracture
- Burns
- Post-operative complications
- Poisoning and toxic exposures
- Smoke inhalation
- Caustic ingestion
- Strychnine poisoning
- Laryngospasm
- Physical or chemical stimuli
- Drug-induced e.g. acute dystonic reaction, ketamine
- Congenital
- Vascular rings
- Laryngeal webs
- Other
- Paradoxical motion of the vocal cords
- Altered level of consciousness
- Cranial nerve palsies
- Paralysis
- Hysterical stridor
- Myoedema
ASSESSMENT
History
- Stridor = sound on inspiration associated with airway narrowing
- stridor @ rest implies a reduction in airway diameter of >50%
- progression of symptoms
- positional exacerbation
- whether patient wakes @ night having difficulty breathing
- dysphagia
- drooling
- severe obstruction -> coughing becomes difficult -> chest infections
Examination
- Airway assessment
- Neck examination
- Nasal endoscopy – photos helpful, doesn’t involve LA to cords which could precipitate total airway obstruction, beaware that a nice view in the sitting position doesn’t mean the same in the supine position.
Investigation
- CT – more helpful in subglottic assessment
Define site of obstruction
- Supraglottic
- Laryngeal
- Subglottic – mid tracheal & lower tracheal/bronchial
MANAGEMENT
Supraglottic & Laryngeal Lesions
- Awake tracheostomy
- Inhalational induction
INHALATIONAL INDUCTION
- 2 anaesthestists
- experienced assistance
- vasoconstrictor + LA to nose
- surgeon in theatre scrubbed for emergency tracheostomy
- sevo/O2 induction (may need halothane)
- don’t bag if becomes apnoeic (allow CO2 rise)
- insert N/P airway if required
- wait for pupils to become small and central
- laryngoscopy (long, McCoy)
- assess whether can intubate
- attempt intubation only twice
- tracheostomy while breathing spontaneously
- sudden complete airway obstruction
-> immediate tracheostomy or single attempt @ rigid bronchoscope
AWAKE TRACHEOSTOMY
Indications
- severe stridor
- large tumour
- gross anatomical distortion
- larynx not visible on nasal endoscopy
Technique
- no sedation
- helium/O2 mix -> improves symptoms
- beaware of giving high FiO2 -> can precipitate CO2 narcosis
- prepare in sitting position
- once in place -> confirm with CO2
Post op
- Analgesia
- Humidification
- If intubated – leave Cook Airway catheter in place until patient fully awake
- Dexamethasone
- May need PEEP or IPPV post
Mid Tracheal Lesions
- ie. thyroid mass
- ensure that patient can be intubated to below level of obstruction
- normal induction may be appropriate
- any suggestion of malignant tracheal invasion -> AFOI
Lower Tracheal & Bronchial Obstruction
- mediastinal masses (lymphoma, invasive carcinoma)
- beaware of invading thyroid carcinomas -> tracheal collapse with muscle relaxation -> have a ridgid bronchoscope available.
- if obstruction close to the carina or invading the bronchus -> can’t do tracheostomy or give muscle relaxation -> may need bypass.
References and Links
CCC Airway Series
Emergencies: Can’t Intubate, Can’t Intubate, Can’t Oxygenate (CICO), Laryngospasm, Surgical Cricothyroidotomy
Conditions: Airway Obstruction, Airway in C-Spine Injury, Airway mgmt in major trauma, Airway in Maxillofacial Trauma, Airway in Neck Trauma, Angioedema, Coroner’s Clot, Intubation of the GI Bleeder, Intubation in GIH, Intubation, hypotension and shock, Peri-intubation life threats, Stridor, Post-Extubation Stridor, Tracheo-esophageal fistula, Trismus and Restricted Mouth Opening
Pre-Intubation: Airway Assessment, Apnoeic Oxygenation, Pre-oxygenation
Paediatric: Paediatric Airway, Paeds Anaesthetic Equipment, Upper airway obstruction in a child
Airway adjuncts: Intubating LMA, Laryngeal Mask Airway (LMA)
Intubation Aids: Bougie, Stylet, Airway Exchange Catheter
Intubation Pharmacology: Paralytics for intubation of the critically ill, Pre-treatment for RSI
Laryngoscopy: Bimanual laryngoscopy, Direct Laryngoscopy, Suction Assisted Laryngoscopy Airway Decontamination (SALAD), Three Axis Alignment vs Two Curve Theory, Video Laryngoscopy, Video Laryngoscopy vs. Direct
Intubation: Adverse effects of endotracheal intubation, Awake Intubation, Blind Digital Intubation, Cricoid Pressure, Delayed sequence intubation (DSI), Nasal intubation, Pre-hospital RSI, Rapid Sequence Intubation (RSI), RSI and PALM
Post-intubation: ETT Cuff Leak, Hypoxia, Post-intubation Care, Unplanned Extubation
Tracheostomy: Anatomy, Assessment of swallow, Bleeding trache, Complications, Insertion, Insertion timing, Literature summary, Perc. Trache, Perc. vs surgical trache, Respiratory distress in a trache patient, Trache Adv. and Disadv., Trache summary
Misc: Airway literature summaries, Bronchoscopic Anatomy, Cuff Leak Test, Difficult airway algorithms, Phases of Swallowing
- CEPD – October 2002 (Rees & Mason)
- Obstructed Airway in ENT Surgery – Anaesthesia 1999, 54, page 625-628 (Mason & Fielder)
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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