Stridor and Sleep Apnoea (DISEASE MECHANISMS) Flashcards
What is stridor?
Stridor is a predominantly inspiratory sound due to large airways obstruction
What are supraglottic/laryngeal causes of inspiratory stridor?
Laryngomalacia
Supraglottic mass
Glottic lesions
Vocal cord paralysis
What can cause stridor in children?
Infections
Foreign bodies
Anaphylaxis / Angioneurmtic oedema
Other (e.g. burns)
Which infections can cause stridor in children?
Croup Epiglottitis Pseudomembranous croup Retropharyngeal abscess Diphtheria Infectious mononucleosis
What is croup?
Laryngotracheobronchitis - commonly caused by RSV
What are the symptoms of croup?
Fever
Barking Cough
Stridor
What is pseudomembranous croup?
Laryngotracheobronchitis of the respiratory epithelium with micro purulent secretions
What commonly causes infectious mononucleosis (aka glandular fever/mono)
Epstein Barr Virus (EBV)
What is angioneurotic oedema?
Rapid swelling of: dermis subcutaneous tissue mucosa submucosal tissues
Which group are most as risk for foreign bodies in the airway
Children under the age of 3
What is the key element in diagnosis foreign body airway obstruction?
History
How do patients with a foreign body airway obstruction usually present?
Acute onset of stridor accompanied by a choking spell
How can a foreign body in an airway be detected?
Airway films and CXR
possibly lateral x-ray of the throat
What are causes of stridor in adults?
Neoplasma Anaphylaxis Goitre Trauma Other
Which neoplasms could cause stridor in adults?
Larynx
Trachea
Major bronchi
Which other causes of stridor are there besides neoplasms anaphylaxis, goitre and trauma?
Bilateral vocal cord palsy
Wegener’s granulomatosis
Cricoarytenoid arthritis
Tracheopathia
How can stridor be investigated?
Laryngoscopy Bronchoscopy Flow volume loop by spirometry CXR (CT/Thyroid scan)
How are laryngeal obstructions treated?
Treat underlying cause
High flow oxygen
Cricothyroidotomy (emergency)
Tracheostomy
What is the Heimlich Manoeuvre?
Rapid upward thrust in epigastrium force upward movement of diaphragm and forced expiration
How can malignant airway obstructions be treated?
Tumour removal (laser / photodynamic therapy / cryotherapy / Diathermy / surgical resection)
Tumour compression (intraluminal stent)
Radiotherapy
(Chemotherapy / Corticosteroids)
What type of hypersensitivity causes anaphylaxis?
Type I hypersensitivity
How does acute anaphylaxis present?
Flushing, pruritus, urticaria Angioneuortic oedema (Abdominal pain, vomiting) Hypotension leading to circulatory collapse (shock) Stridor, wheeze and respiratory failure
What are causes of anaphylaxis?
Food allergy
Insect venom
Drugs
Other e.g. latex
How is acute anaphylaxis treated?
IM Epi within minutes IV antihistamine within half hour IV corticosteroid within hour High flow O2 Nebuliser bronchodilators Endotracheal intubation if necessary
How can anaphylaxis be managed long-term?
Avoidance
Immunotherapy
Self-admin epinephrine
What causes snoring?
Relaxation of pharyngeal dilator muscles during sleep (esp. REM sleep) causes upper airway narrowing, turbulent airflow and vibration of soft palate and tongue base producing sound
What causes sleep apnoea?
Negative pressure from breathing in obstructs airway if the throat is floppy causing microarousal to re-establish airflow
What is obstructive sleep apnoea?
Intermittent upper airway collapse in sleep
Can be apnoeas or hypo apnoeas +/- hypoxaemias
Include recurrent arousals and sleep fragmentation
What are the risk factors for sleep apnoea?
Enlarged tonsils/adenoids
Obesity
Retrognathia
Acromegaly/Hypothyroidism
Oropharyngeal deformity
Neuro: Stroke / MS / Myasthenia gravis / Myotonic dystrophy
Drugs: Benzodiazepines / opiates / alcohol / post-op period after anaesthesia
What is retrognathia?
Jaw is set back and tongue is further back resulting in less space in the oropharynx
Why ca sleep apnoea occur after anaesthesia?
Muscle relaxant is part of anaesthetic
What are consequences of Sleep apnoea?
Excessive daytime sleepiness personality change Cognitive and/or functional impairment Major impact on daytime function 7-fold increased risk in RTA independent risk for hypertension Activated sympathetic system Raised CRP Impaired endothelial function Impaired glucose tolerance Increased risk of stroke & CVS events
How is obstructive sleep apnoea diagnosed?
Snoring& EDS (raised Epworth score)
Overnight sleep study - domiciliary recording / full poysomnography
What is included in domiciliary recording?
Airflow
Oximetry
Thoracic and abdominal movement
What is polysomnography used for?
Establish they don’t have narcolepsy or REM sleep disorders
How is obstructive sleep apnoea treated?
Remove underlying cause
CPAP (most effective)
What does CPAP stand for?
Continuous positive airway pressure
What are other treatment options for sleep apnoea besides CPAP?
Mandibular advancement device
Surgery (avoid in sleep apnoea because reduces future CPAP efficacy, used in simple snoring)
