Stridor
OVERVIEW
- Stridor = sound on inspiration associated with airway narrowing
HISTORY
- stridor at rest implies a reduction in airway diameter of >50%
- progression of symptoms
- positional exacerbation
- whether patient wakes at 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, be aware 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
- Inhalational induction
- Awake tracheostomy
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 NP airway if required
- wait for pupils to become small and central
- laryngoscopy (long, McCoy)
- assess whether can intubate
(1) attempt intubation only twice (2) 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
- be aware 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 -> awake fiberoptic intubation (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
Textbooks and journal articles
- Hillman DR, Platt PR, Eastwood PR. The upper airway during anaesthesia. Br J Anaesth. 2003 Jul;91(1):31-9. PMID: 12821563. [Fulltext]
- Mason RA, Fielder CP. The obstructed airway in head and neck surgery. Anaesthesia. 1999 Jul;54(7):625-8. PMID: 10417451.
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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