Airway Obstruction Flashcards
When does the URT end and the LRT begin?
Vocal cords
Movement of the vocal cords during phonation?
Adduct
Movement of the vocal cords during respiration?
Abduct (action of posterior cricoarytenoid muscles)
Features in the neonate that alter the airway?
Neonates are OBLIGATE NASAL BREATHERS
Relatively large tongue
Narrow subglottis (3.5mm at the cricoid)
Structure of the larynx in neonates?
Small, soft larynx that is in a higher position
They have weak neck muscles and floppy head
Describe Poiseuille’s equation
Blowing air through a tube with a decreasing diameter results in the resistance to flow increasing to the 3rd power of the radius
Thus, a slight reduction in diameter massively increases resistance
Describe the Bernoulli principle/Venturi effect
………..
Causes of airway obstruction?
Inflammatory/infective/allergy
Foreign body inhalation
Physical compression/invasion of the airway
Neoplastic causes, e.g: malignant pathology
Trauma (may be iatrogenic)
Burn
Congenital airway pathology
Signs and symptoms of airway obstructor?
- SoB on exertion OR at rest (stertor/stridor); coughing/choking
- Inability to complete a sentence (good marker of severity)
- Sternal/subcostal recession
- Tracheal tug
- Dusky skin colour of skin
- Dysphagia, dysphonia
- Pyrexia and cyanosis
What is stridor?
High-pitched harsh noise due to turbulent airflow caused by airway obstruction; typically inspiratory
What is stertor?
Low-pitched sonorous sound arising from the nasopharyngeal airway, e.g: during a cold
Consequences of enlarged tonsils and adenoids?
Obstructive sleep apnoea
Management of airway in acute epiglottitis?
Require intubation
Consequences of inhaling a peanut (foreign body)?
Airway obstruction
NOTE: peanuts are toxic and cause swelling
CXR appearance of foreign body inhalation into the left main bronchus?
Shows mediastinal shift
What is recurrent respiratory papillomatosis?
HPV causees papillomas to develop over time
Treatment of recurrent respiratory papillomatosis?
Intubation + surgery + anti-virals
What is sub-glottic stenosis?
Narrowing of the subglottis (just below the vocal cords); can be:
• Congenital
• Idiopathic (unknown cause)
• Acquired (majority are post-intubation)
How can burns cause airway obstruction?
Assoc. swelling
How to assess a patient with potential airway obstruction?
Appearance (anxious-looking, sternal recession, etc)
Work of breathing
Skin circulation
Pathway of deterioration following airway obstruction?
- Respiratory distress
- Respiratory failure
- Respiratory arrest
- Cardiac arrest
Respiratory, cardiac and neurological failure are all linked
Describe cardiorespiratory drive
If one fails, the other will as well
Mx of airway obstruction?
ABC
Administer: • Oxygen • Heliox (79% helium + 21% oxygen; makes air thinner and easier to inhale) • Steroids • Adrenaline
Secure the airway with:
• Endotracheal tube (intubation)
• Tracheostomy (avoid as there is an assoc. morbidity and mortality)
Treat the underlying pathology
Methods of Ix of the airway?
Rigid endoscopy and/or flexible endoscopy; this is best done without the ET tube in place, if possible
Options include:
• Direct laryngoscopy or microlaryngoscopy
• Exam with Hopkins rod
• Laryngotracheobronchoscopy
Types of general anaesthesia?
Anaesthetic gas (Sevoflurane)
IV anaesthesia (Propofol, Remifentanyl)
Pharmacotherapy for airway obstruction?
Heliox
Nebulised budesonide
Dexamethasone
Nebulised adrenaline
