1. Airway obstruction
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This requires immediate treatment and is why we as ICU physicians and anaesthetists drill so thoroughly to deal with these situations.

Remember, patients die because of failed oxygenation and ventilation; not failed intubation. Basic airway management skills (e.g. bag and mask ventilation using simple airway adjuncts) are therefore paramount! Do not delay and avoid task fixation; simple measures FIRST.


  • Internal obstruction
    • Foreign body or tumour
    • Airway bleeding/trauma
    • Aspiration vomit
    • Upper airway infection (e.g. epiglottitis, retropharyngeal abscess)
  • Swelling/oedema
    • Angio-oedema (ACE inhibitors, aspirin, hereditary C1-esterase deficiency
    • Anaphylaxis
    • Following upper airway interventions or surgery (including post-extubation laryngeal oedema)
    • Airways burns or inhalation of smoke/toxic fumes
  • External obstruction
    • Swelling/oedema: neck trauma, external mass or tumour
  • Haematoma (especially in coagulopathic or anti-coagulated patients)
  • Neck trauma
    • Following thyroid or carotid surgery
    • Following internal jugular line insertion
  • Neurological causes
  • Diminished level of consciousness (e.g. intoxication, head injury/CVA,cardiac arrest)
  • Laryngospasm (especially in semi-conscious patients)
  • Paralysis of vocal cords
    • Neurological disease (e.g. myasthenia gravis, Guillain Barré, poly- neuritis, or recurrent laryngeal nerve damage)
    • Inadequate reversal of muscle relaxants


  • Partial obstruction
    • Anxiety
    • Patient prefers sitting, standing or leaning forward
    • Inability to speak or voice change (muffled or hoarse voice)
    • Stridor (inspiratory noise accompanying breathing) or noisy breathing
    • Obvious neck swelling
    • Lump in throat, difficulty in swallowingChoking
    • Coughing
    • Drooling
  • Respiratory distress
    • Tachypnoea and dyspnoea
    • Use of accessory muscles of respiration
    • Paradoxical breathing: indrawn chest and suprasternal recession
    • Tracheal tug
    • ‘Hunched’ posture
  • Total or near-total obstruction
    • Hypoxia, cyanosis, hypercapnia
    • Bradycardia, hypotension
    • Diminished or absent air entry
    • Decreased consciousness
    • Cardiac/respiratory arrest, where bag and mask ventilation impossible



  • ABGs (hypoxia, hypercapnia)
  • FBC (increased WCC in infection)
  • Clotting screen (coagulopathy)
  • Blood cultures and oropharyngeal swabs
  • Imaging
    • neck X-ray (AP & lateral)
    • CXR
    • CT scan may be required
  • Fibre-optic endoscopy or direct laryngoscopy
    • Although nasendoscopy will potentially allow a view of the airway and aid diagnosis, it requires skill to be done safely
    • Direct laryngoscopy should not be attempted unless the airway is already secured, or all preparations are in place to immediately secure the airway (see section on immediate management)

****Airway interventions in a patient with a partially obstruct- ed airway can provoke complete airway obstruction


  • Equipment failure (e.g. incorrectly assembled self-inflating ambu-bag)
  • ETT or tracheostomy obstruction
  • Conditions which result in noisy breathing
    • Bronchospasm
    • Hysterical stridor
  • Conditions which result in difficulty breathing spontaneously or high airway pressures when ventilating patient
    • Bronchospasm
    • Tension pneumothorax
  • Conditions which result in patients adopting a sitting or leaning for- ward position
    • SVC obstruction
    • Cardiac tamponade


  • 100% O2, pulse oximetry
  • Assess condition of patient and likely cause of airway obstruction
  • Support ventilation with bag and mask if required

If patient has suffered cardiac/respiratory arrest:

  • Follow BLS guidelines (Here)
  • Support/open airway; use adjuncts (oropharyngeal or nasopharyngeal airways) and suction
  • Remove obvious obstruction and commence CPR (ALS algorithm)

If patient is peri-arrest:

  • Call for skilled help: anaesthetist, ENT surgeon, your other ITU colleagues
  • Obstruction requires immediate laryngoscopy (direct with a laryngoscope!!)/tracheal intubation
  • Surgical airway i.e. cricothyroidotomy or tracheostomy for total obstruction if the above fails

If airway obstruction is due to diminished consciousness:

  • Call for skilled anaesthetic assistance
  • If traumatic: assume c-spine injury and asses for other injuries
  • Consider replacing hard-collar with manual in-line stabilization (often helpful when supporting airway, required prior to intubation)****Ensuring an adequate airway always overrides concerns about potential c-spine injuries
  • Support/open airway; use adjuncts (oropharyngeal or nasopharyngeal airways) and suction
  • Support ventilation with bag and mask if required
  • Proceed to definitive airway, most commonly rapid sequence intubation 
  • Cricothyroidotomy or tracheostomy is indicated in the event of failed intubation***If airway obstruction is due to airway swelling, infection or physical obstruction; call for senior help (anaesthetic and ENT)
  • Formulate an airway management plan and arrange for equipment to be available (e.g. plan A: endotracheal intubation; plan B: laryngeal mask airway; plan C: temporary cricothyroidotomy); CICV drill
  • Arrange equipment for inhalational induction (anaesthetic machine with anaesthetic gas sevoflurane or halothane)
  • Consider transferring patient to operating theatre where above equipment is present if patient stable enough
  • Temporary measures which may be used whilst arranging the above include: nebulised adrenaline (5mg / 5ml 1:1000 in a nebuliser) and/or humidified oxygen or heliox

***Early intubation should be considered to reduce the risk of sudden deterioration and airway obstruction

  • Cricothyroidotomy or tracheostomy is indicated in the event of failed intubation and ventilation, or as initial management plan under local anaesthesia

Other considerations requiring simultaneous treatment:
  • Anaphylaxis
    • IV or IM adrenaline, steroids, anti-histamines
  • Haematoma after neck surgery
    • remove dressings, cut open sutures
  • Airway bleeding
    • correct coagulopathy
  • Facial trauma
    • simultaneous assessment of c-spine and other associated trauma
  • Laryngospasm:
    • support ventilation with bag and mask ventilation
    • apply PEEP (easier using a Water’s or C-circuit)
    • low dose propofol, 10-20mg IV, and low dose suxamethonium, 10-15mg IV have been successfully used
    • intubation must be immediately available
  • Inadequate reversal of muscle relaxants
    • treat for laryngospasm
    • consider reversal with IV neostigmine 2.5mg mixed with glycopyrronium bromide 0.5mg (only works if reversing a non-depolarising muscle relaxant that is already beginning to wear off)
    • alternatively suggamadex 2-4mg/kg IV may reverse muscle relaxation with vecuronium or rocuronium
  • Post extubation oedema
    • nebulised adrenaline, IV steroids
  • Angiooedema which is non-allergic
    • this should be treated as allergic in the first instance
    • where there is a clear history of hereditary angiooedema consider C1 esterase inhibitor concentrate, icatibant, tranexamic acid, or danazol (seek specialist advice first)

***In stable patients where diagnosis/degree of obstruction is in doubt nasal endoscopy performed by an experienced ENT surgeon may help. Be prepared to intubate or per- form cricothyroidotomy/tracheostomy if total airway obstruction is provoked

  • Once Airway and Breathing are stabilised continue ABC approach – Transfer to critical care environment for close observation


  • Only if condition is stable and the airway obstruction has been relieved
    • Nurse patient 30-45 ° head up to promote venous drainage
    • Consider iv dexamethasone to reduce any further airway swelling
    • Ventilation and sedation for a number of days on ICU may be required for intubated patients until the cause of obstruction resolves
    • Adopt a lung-protective ventilation strategy (Link needed)
    • Surgical or microbiology opinions may be required
    • Supportive measures for sepsis may be required
    • Assess airway swelling (laryngoscopy and/or cuff-leak test) prior to extubation
    • Where intubation is likely to be prolonged, or airway obstruction may recur after extubation, consider elective tracheostomy


  • Delaying intubation may make a difficult intubation impossible
  • Deterioration to complete obstruction may progress rapidly over a few hours
  • Cardiovascular collapse may mask airway signs
  • Airway interventions in a patient with a partially obstructed airway can provoke complete airway obstruction
  • Insertion of oropharyngeal or nasopharyngeal airway in patients with retropharyngeal abscess may burst the abscess and soil the airway
  • It is important to recognize patients in whom endotracheal intubation is likely to be difficult
  • Obtaining a definitive airway via endotracheal intubation or surgical tracheostomy can be challenging in the face of airway obstruction, the priority is always to maintain oxygenation
  • Cricothyroidotomy (Link needed) should only be attempted by inexperienced operators in circumstances where the patient is otherwise likely to die


Everyone’s nightmare situation! These can rapidly cause airway obstruction within hours, therefore the utmost vigilance is needed and the good old uncut dangly ET tube! The other thing to think about is the fact that there may be noxious gases involved that may ultimately impair gas exchange.

What’s breathed in up top will inadvertently cause damage to the primary airways and lung too, so be prepared!


  • Direct contact thermal burns to the face or airway
    • Airway fires (rare outside operating theatres)
    • Trapped/unconscious near a heat source
    • Inhalation of hot or corrosive gas
  • Entrapment near a burning substance (house fire, car fire)
  • “Flashbacks” of hot gases (foundry accidents, aerosol can fires)
  • Inhalation of steam or drinking hot fluids
    • Drinking corrosive fluids (e.g. bleach)


Look for these cardinal warning signs of impending airway obstruction!!!


  • Facial oedema is already present
  • Marked facial burns are present (blistering, pealing skin)

Inside of the mouth and nose

  • Airway oedema or blistering/pealing of mucosal membranes present


  • Circumferential or marked anterior neck burns are present
  • Laryngeal structures are no longer palpable


  • Difficulty swallowing, drooling
  • Carbonaceous sputum
  • Inability to speak or vocal changes (muffled or hoarse voice) – Inspiratory stridor or noisy breathing
  • Respiratory distress (looks like a croup child!)
    • Tachypnoea, dyspnoea, wheeze, cough
    • Use of accessory muscles of respiration, tracheal tug
    • Paradoxical breathing
    • Patient prefers sitting, standing or leaning forward


***Secure the airway first before mucking about with tests!!

  • ABGs (hypoxia, metabolic acidaemia)
    • Lactate (may be increased)
    • Carboxyhaemoglobin using co-oximetry (COHb may be increased)
  • FBC, cross match, U&Es
    • CXR
    • C-spine and trauma-series X-rays (if appropriate)


  • 100% O2, pulse oximetry
  • Assess degree of burn and airway obstruction
  • If associated trauma simultaneously assess C-spine and other injuries

 If patient already has evidence of airway obstruction:

  • Call for senior help (anaesthetic and ENT)
  • Consider nebulised adrenaline (5mg/5ml 1:1000 in a nebuliser)
  • Consider nasal endoscopy to asses degree of airway oedema
  • Prepare equipment for Rapid Sequence Intubation or inhalationalinduction (anaesthetic machine with anaesthetic gas sevoflurane)
  • Prepare difficult airway equipment 
  • Laryngoscopy/intubation will be required (use uncut endotrachealtubes in case of later facial swelling)
  • Cricothyroidotomy or tracheostomy is indicated in the event offailed intubation, or as the first-line technique***If patient is at risk of airway obstruction early, more elective intubation should be performed using an uncut endotracheal tube
  • Once Airway and Breathing are stabilised continue ABC approach
  • Follow trauma/ATLS principles as part of primary survey
  • Assess any associated chest and lung burns 
  • Urgent management of circumferential burns (especially neck and chest) may be required
  • Raised COHb levels require an FiO2 of 100% initially
  • Fluid resuscitate using a burns protocol


  • Assess and treat other traumatic injuries as part of secondary survey
  • If intubated, consider ventilation and sedation on ICU for a number ofdays until airway inflammation has resolved; assess airway swelling (by laryngoscopy and/or cuff-leak test using ventilator) before extubation
  • Consider transfer to burns unit, anaesthetic assessment of airway risk may be required in un-intubated patients
  • Treat inhalational injury
  • Consider giving antibiotics and check tetanus status


***If in doubt intubate, as delay may make a difficult intubation impossible. Complete airway obstruction can occur  extremely rapidly!!***

  • Hoarse voice is an early sign of laryngeal oedema
  • Trauma including chest, head and neck injuries are common

***Using suxamethonium >48 hours after burn may cause hyperkalaemia**




There will be further detail on this topic later, this is a brief introduction.


  • Extrinsic
    • Pharyngeal, retropharyngeal or peri-tonsillar abscess
  • Ludwig’s angina (soft tissue infection of the floor of the mouth)
  • Deep-neck infections

Can be caused by streptococci or staphylococci, but may be polymicrobial and include anaerobic or Gram-negative organisms

  • Intrinsic
    • Diphtheria: airway inflammation and a greyish pseudo-membrane in the respiratory tract (caused by Corynebacterium diphtheriae)
    • Epiglottitis: inflammation of epiglottis, vallecula, aryepiglottic folds, and arytenoids (commonly Haemophilus species, but also Strep. pneumoniae and S. aureus)


  • Poor dental hygiene
  • Recent sore throat, tonsillitis, pharyngitis, URTI
  • Recent oral/pharyngeal surgery/trauma


  • Depending on cause, may include:
    • Tachypnoea, dyspnoea, hypoxia and cyanosis
    • Stridor
    • ‘Hunched’ posture; sitting forward, mouth open, tongue protruding – ‘Muffled’ or hoarse voice, painful swallowing, drooling
    • Neck swelling, cervical lymphadenopathy
    • Trismus, neck pain, neck stiffness
    • Fever and signs of systemic sepsis
    • Diphtheria exotoxin may cause CNS symptoms or cardiac failure
    • Infection may spread causing: pneumonia, mediastinitis, pericarditis,


  • FBC (raised WCC)
  • Blood cultures and throat swabs*
  • Laryngoscopy (indirect/fibre-optic) performed by a skilled operator*
  • CXR (if mediastinal/chest involvement suspected)
  • Lateral soft tissue neck X-ray may demonstrate soft tissue swelling and ‘thumb sign’ and ‘vallecula’ signs in epiglottitis
  • CT or MRI of head and neck

***Airway interventions in a patient with a partially obstructed airway can provoke complete airway obstruction***


  • Airway foreign body or tumour


  • Humidified 100% O2, pulse oximetry
  • Rapid assessment (note that manipulating airway or adjusting patient position may completely obstruct airway, particularly in children)

!!If in extremis!!

  • Call for senior help (anaesthetic and ENT)
  • Elective intubation is required, prior to complete airway obstruction
  • Prepare difficult airway equipment and equipment for inhalational induction (anaesthetic machine with sevoflurane)
  • Consider transferring patient to operating theatre or critical care area where above equipment is present, if this is quicker
  • Surgical tracheostomy by a skilled surgeon is indicated in the event of a ‘failed intubation’, or as the first-line technique
  • If there is a need to “buy” time waiting for senior help consider: Heliox or nebulised adrenaline (5mg/5ml 1:1000 in a nebuliser)


In more stable patients:

  • Transfer to critical care environment for close observation
  • The risk of airway obstruction may still mandate early intubation

Once Airway and Breathing are stabilised continue ABC approach

  • Take blood cultures and pharyngeal/epiglottic swabs
  • Obtain IV access and consider steroids (dexamethasone 8mg IV)
  • Empirical antibiotics will depend upon the type of infection (seek microbiological advice), but may include:
    • Epiglottitis: cefotaxime 1-2g IV 12-hourly
    • Deep-seated neck infections: clindamycin 600mg IV 6-hourly, benzyl penicillin 600mg IV 6-hourly, metronidazole 500mg IV 8-hourly
    • For diphtheria: clarithromycin 500mg IV 12-hourly, and possibly anti-toxin (if strain is toxin producing)**For those patients in-extremis, blood cultures and epiglottic swabs should not be obtained until airway is secured**


  • Ventilation and sedation may be required for a number of days until inflammation has resolved
  • Surgical drainage of abscesses and collections may be required
  • Supportive measures on the ICU for septic patients 
  • Assess airway swelling (laryngoscopy/cuff-leak test) before extubation


  • Delaying intubation may make a difficult intubation impossible
  • Failure to appreciate how rapidly these conditions can progress, normal to complete airway obstruction in only a few hours



This section may be particularly poignant when treating patients requiring instrumentation, tracheostomy of those with autoimmune / vascular states.


  • Following airway surgery or interventions (e.g. tonsillectomy)
  • Following upper airway interventions, especially tracheostomy
  • Upper airway infection
  • Airway or neck trauma
  • Airway or neck tumours
  • Smoker or previous history of cancer
  • Coagulopathic or anticoagulated patients
  • Epistaxis may occasionally be so severe as to compromise the airway


  • Anxiety
  • Haemoptysis, epistaxis, or spitting blood
  • Airway obstruction: stridor (inspiratory noise accompanying breathing), use of accessory muscles, paradoxical breathing
  • Alveolar soiling: cough, widespread crepitations, diminished air entry
  • Respiratory distress
    • Paradoxical breathing: indrawing chest and suprasternal recessionAltered consciousness, hypoxia, cyanosis, and bradycardia, are preterminal signs
    • Tachypnoea and dyspnoea
    • Respiratory accessory muscle usage, diminished/absent air entry

Where tumour is the cause, the following may also be present:

  • Recurrent or persistent pneumonia
  • Hoarse voice and/or persistent cough
  • Cervical, supraclavicular, or axillary lymphadenopathy
  • Obstruction or respiratory distress of gradual onset


  • Diagnosis is clinical; investigations may have to wait until airway is secure
    • ABG
    • FBC, cross match
    • Coagulation screen
    • Blood and sputum cultures if there is evidence of co-existing infection
  • Imaging: CXR, neck X-ray CT scan
  • When possible endoscopy, direct laryngoscopy will aid diagnosis and allow interventions to restore airway patency


  • Haemoptysis due to pulmonary haemorrhage – Pulmonary oedema
  • Upper airway infection
  • Foreign body


  • 100% O2, pulse oximetry
  • For trauma patients: simultaneously assess C-spine and other associated trauma
  • Assess the degree of bleeding and extent of lung soiling, if severe:
    • Call for senior help (anaesthetic and surgical/ENT)
    • The first priority is to secure patency of airway
    • Airway obstruction will require immediate laryngoscopy, suctioning of the upper airway and tracheal intubation
    • Two suction devices may be needed if bleeding is rapid
    • The aim should be to place the cuff of an ETT beyond the site of haemorrhage or insert Double Lumen Tube (DLT) if haemorrhage is pulmonary and unilateral in origin.
    • Surgical airway (cricothyroidotomy or tracheostomy) may be needed if intubation fails (See here)
    • Surgical control of bleeding should then be attempted
    • Urgent fibre-optic bronchoscopy may be required to removeclots from lower airways
  • Where bleeding is not severe airway obstruction may still be a risk,especially if airway tumour is present
    • Make as full assessment as possible as detailed above; including CT scanning if the clinical situation allows
    • Airway manipulation may provoke complete obstruction
    • Once Airway and Breathing are stabilised continue ABC approach
    • Establish IV access and restore circulatory volume with fluid/colloid – Blood and blood product transfusion may be required


  • Fibre optic laryngoscopy or bronchoscopy to assess the source of haemorrhage
  • Assessment by ENT surgeon and/or thoracic surgeon for more definitive management of bleeding
  • Sedate and ventilate in intensive care until haemorrhage is controlled or if oxygenation is poor despite a patent airway
  • Circulatory support including inotropes may be required
  • Antibiotics for prophylaxis or treatment of concurrent infection maybe required


  • Deterioration may be rapid
  • Don’t use sedatives unless airway is secure
  • In extensive lung soiling hypoxia may not be relived by securing airwayand ventilation; also watch for development of pneumonia or ARDS