Airway Compromise: Recognition and Emergency Management

Introduction

Airway compromise describes partial or complete obstruction of the upper airway, and is one of the true time-critical emergencies in medicine - regardless of the underlying cause, the priority is recognising it early and securing help before obstruction becomes complete.¹ Causes range from infective (epiglottitis, deep neck space infection) to traumatic, allergic, and neoplastic, but the immediate assessment and escalation principles are shared across all of them.

This article draws together airway threats already touched on elsewhere - epiglottitis, quinsy, mastoiditis, anaphylaxis, and bilateral vocal cord palsy - into a single framework for recognising and managing the deteriorating airway.

Causes

Infective

• Acute epiglottitis: classically Haemophilus influenzae type b, now rare due to vaccination but still seen; rapid-onset fever, drooling, muffled voice and stridor, with a child (or adult) sitting forward in a tripod position
• Deep neck space infection: quinsy, parapharyngeal or retropharyngeal abscess, each capable of causing swelling that compromises the airway
• Ludwig's angina: a rapidly spreading infection of the submandibular space, usually from a dental source, pushing the tongue up and back and threatening the airway
• Croup (laryngotracheobronchitis): a paediatric viral illness (usually parainfluenza) causing a barking cough and stridor, most managed conservatively but occasionally severe
• Bacterial tracheitis: rare but severe, can mimic or complicate croup

Other causes

• Trauma: direct laryngeal injury, neck haematoma (traumatic or post-surgical, e.g. after thyroidectomy or carotid endarterectomy), inhalation/burn injury causing progressive oedema
• Foreign body aspiration: sudden-onset choking, which can cause complete obstruction
• Anaphylaxis and angioedema: laryngeal oedema as part of a systemic allergic reaction, or isolated angioedema (ACE inhibitor-induced, or hereditary angioedema from C1 esterase inhibitor deficiency)
• Bilateral vocal cord palsy: both cords sitting close to the midline obstructing airflow, most often following bilateral thyroid surgery injury
• Tumour: laryngeal, hypopharyngeal or thyroid malignancy causing progressive, and occasionally acute, obstruction

Recognition

Stridor is the cardinal sign of upper airway obstruction - a harsh, high-pitched sound, typically inspiratory with obstruction above the larynx, becoming biphasic as obstruction worsens or involves the larynx/trachea itself.^1,2 Other features include a muffled or "hot potato" voice, drooling (suggesting inability to safely swallow secretions), and the patient adopting a tripod position (sitting forward, leaning on outstretched arms) to maximise airway patency.

Look for accessory muscle use, tracheal tug, and intercostal or subcostal recession, all indicating significantly increased work of breathing. Agitation or confusion can be an early sign of hypoxia, and should never be dismissed as simple anxiety in a patient with a plausible airway threat.

General assessment principles

The overriding principle in suspected airway compromise, especially epiglottitis in a child, is to avoid distressing the patient. Do not attempt to examine the throat with a tongue depressor, insert a cannula, or lie the patient flat if they are maintaining their own airway by choosing a particular position - agitation and crying increase oxygen demand and can precipitate complete obstruction in a critically narrowed airway.¹

Allow the patient to remain in their position of comfort, provide oxygen in a way that is tolerated (blow-by rather than a forced mask in a distressed child), and call for senior anaesthetic, ENT and (in children) paediatric input early - this is not a situation to manage alone or to delay while awaiting further tests.

Cause-specific management

Epiglottitis: keep the patient calm; the airway is secured under controlled conditions in theatre, usually by gaseous induction with the anaesthetist ready to perform a surgical airway if intubation fails, followed by IV antibiotics and dexamethasone once the airway is safe.¹

Anaphylaxis: intramuscular adrenaline without delay, following the standard anaphylaxis algorithm, alongside oxygen, IV fluids, and antihistamine/corticosteroid as adjuncts. ACE inhibitor-induced angioedema is bradykinin-mediated and responds poorly to adrenaline, antihistamines or steroids; management is supportive with early airway assessment, and the ACE inhibitor is stopped and never restarted. Hereditary angioedema is treated with C1 esterase inhibitor concentrate or icatibant where available.

Foreign body aspiration: the standard choking algorithm (back blows and abdominal/chest thrusts) applies for acute complete obstruction; a lodged foreign body causing partial obstruction needs urgent removal by rigid laryngoscopy/bronchoscopy.

Ludwig's angina: IV antibiotics and urgent surgical drainage, with early anaesthetic involvement since the distorted floor-of-mouth anatomy makes this a recognised difficult airway, sometimes requiring awake fibreoptic intubation or tracheostomy rather than standard induction.

Croup is managed with oral dexamethasone for most cases, with nebulised adrenaline reserved for severe respiratory distress, and the great majority settle without needing airway intervention.

Definitive airway management

When the airway cannot be maintained by simpler measures, tracheal intubation by an experienced anaesthetist is usually attempted, but airway pathology can make this difficult or impossible, so senior input and preparation for a difficult airway (including a surgical back-up plan) is essential whenever the airway is at risk from local swelling or distorted anatomy.²

In the "can't intubate, can't oxygenate" (CICO) scenario - the most feared airway emergency - the definitive rescue is emergency front-of-neck access, most often a cricothyroidotomy, creating a surgical airway through the cricothyroid membrane. This follows structured algorithms (e.g. Difficult Airway Society guidance) designed to prevent delay and hypoxic injury while this decision is made. A planned, formal tracheostomy performed in theatre is used instead when a difficult airway is anticipated in advance, such as for major head and neck tumour surgery.

Complications

• Hypoxic brain injury from prolonged or unrecognised obstruction
• Cardiac arrest if obstruction becomes complete and is not rapidly relieved
• Aspiration
• Complications of a surgical airway itself - bleeding, pneumothorax, or tube misplacement
• Psychological impact of a critical airway event, both for the patient and, where applicable, their family

Red flags

Prognosis

With prompt recognition and early senior involvement, outcomes for airway compromise are generally excellent, and most causes - even epiglottitis and severe croup - resolve completely once appropriately treated.¹ The prognosis worsens sharply with any delay in recognition or escalation, which is why the emphasis throughout airway teaching is on early, low-threshold escalation rather than waiting for unequivocal signs of critical obstruction before acting.