Airway Assessment and Management

Introduction

Airway management is the first priority in any acutely unwell patient, because an obstructed airway kills faster than any other physiological problem. Managing it well means two related skills: recognising when the airway is or is about to become compromised, and working through an escalating sequence of interventions matched to that severity and to the rescuer's own competence.

The guiding principle is to anticipate difficulty before it happens. A brief, structured assessment can predict a difficult airway in advance, giving time to call for senior or anaesthetic help, gather appropriate equipment, and plan for failure before a crisis is already underway.¹

Assessing the airway

Assess by looking, listening and feeling: look for chest and abdominal movement and use of accessory muscles, listen for added sounds at the mouth, and feel for air movement at the mouth and nose.²

Predicting a difficult airway: LEMON

A structured assessment, ideally performed before any attempt at intubation, flags features that predict difficulty and should prompt calling for more senior help in advance rather than discovering the problem mid-attempt.

The escalation ladder

Airway management follows an escalating sequence, moving to the next step only as needed and only within the rescuer's competence - each step buys time and improves the airway, without necessarily being definitive.

1. Positioning and basic manoeuvres

• Head tilt-chin lift - opens the airway by lifting the tongue off the posterior pharyngeal wall; avoided if cervical spine injury is suspected
• Jaw thrust - achieves the same effect without moving the neck, and is the manoeuvre of choice when spinal injury is a concern
• Suction under direct vision to clear blood, vomit or secretions

2. Simple adjuncts

• Oropharyngeal (Guedel) airway - sized from the corner of the mouth to the angle of the jaw; used only in an unconscious patient without a gag reflex, since insertion in an awake or lightly obstructed patient risks vomiting or laryngospasm
• Nasopharyngeal airway - sized from the nostril to the tragus of the ear; better tolerated with some gag reflex present, but used with caution (or avoided) if a base of skull fracture is suspected, given a small risk of intracranial placement

Bag-valve-mask ventilation

Effective mask ventilation is a skill in its own right and often the technique that buys the most time in an emergency. A good seal, an open airway (with an adjunct in place) and a two-person technique - one provider holding the mask with both hands using a 'C-E' grip while the other squeezes the bag - achieves far more reliable ventilation than a single-handed attempt, and should be used without hesitation whenever a single operator is struggling to maintain a seal.

3. Supraglottic airway devices

Devices such as an i-gel or laryngeal mask airway sit above the glottis and provide a more secure airway and better ventilation than simple adjuncts, without requiring direct laryngoscopy. They are quicker and easier to place than a tracheal tube, making them a common first step in resuscitation, but they do not fully protect against aspiration in the way a cuffed tracheal tube does.

4. Definitive airway

A cuffed tracheal tube, placed via direct or video laryngoscopy, is the definitive airway - it protects against aspiration and allows reliable positive pressure ventilation. Placement needs training and, outside cardiac arrest, is usually achieved via rapid sequence induction.

Rapid sequence induction

Rapid sequence induction (RSI) is used to secure a definitive airway quickly in a patient considered at risk of aspiration (a full stomach, reduced consciousness, or an emergency where fasting status is unknown), minimising the time the airway is unprotected between loss of consciousness and tube placement.

• Preparation - equipment, suction, drugs and a plan for failure all ready before induction begins
• Pre-oxygenation with high-flow oxygen for several minutes, to extend the safe apnoea time available during the procedure
• Induction and paralysis given together - a fast-acting induction agent (for example propofol or ketamine) with a rapid-onset neuromuscular blocker (suxamethonium or high-dose rocuronium), rather than the staggered approach used for an elective anaesthetic, to minimise the window during which the airway is unprotected
• Laryngoscopy and tube placement, with confirmation by waveform capnography - the definitive way to confirm correct tracheal (rather than oesophageal) placement

The can't intubate, can't oxygenate emergency

'Can't intubate, can't oxygenate' (CICO) describes the rare but catastrophic situation where neither a tracheal tube, a supraglottic device, nor bag-valve-mask ventilation can achieve oxygenation. It is one of the few true airway emergencies requiring an immediate surgical airway rather than further attempts at the techniques that have already failed.

The emergency front-of-neck airway is achieved through the cricothyroid membrane, identified by palpating the gap between the thyroid and cricoid cartilages in the midline of the neck. A scalpel-bougie-tube technique (a horizontal stab incision through skin and membrane, a bougie passed through the incision to confirm and maintain tracheal placement, then a small cuffed tube railroaded over it) is now the widely taught approach in the UK, favoured over needle cricothyroidotomy with jet ventilation for its speed and reliability once trained.

Specific difficult airway scenarios

• Facial or laryngeal trauma - distorted anatomy and bleeding into the airway make both visualisation and mask ventilation difficult; involve anaesthetics and ENT/maxillofacial early
• Inhalation injury and burns - airway swelling progresses over hours, so the threshold for early, elective intubation is deliberately low, before the airway becomes difficult or impossible to secure
• Anaphylaxis - laryngeal and tongue swelling can progress rapidly; a difficult airway may develop within minutes
• Epiglottitis - avoid examining the throat or upsetting the patient, since agitation can precipitate complete obstruction; involve anaesthetics and ENT early and manage in a controlled environment (often theatre) rather than attempting airway instrumentation on the ward or in the emergency department

Complications

• Aspiration - the risk this whole escalation ladder is designed to minimise, particularly during induction and before a cuffed tube is in place
• Oesophageal intubation - unrecognised, this is rapidly fatal; capnography is what prevents it going unnoticed
• Dental and soft tissue trauma during laryngoscopy, more likely with a difficult view or a rushed attempt
• Laryngospasm, particularly with airway instrumentation at an inadequate depth of anaesthesia
• Cardiovascular instability during induction, especially in an already shocked or hypoxic patient - induction agents and positive pressure ventilation both tend to reduce venous return and blood pressure
• Hypoxia during prolonged attempts - a strict self-imposed time limit for any single attempt, with a return to bag-valve-mask ventilation if it is exceeded, is standard practice precisely to avoid this

Red flags

Prognosis

Outcome from airway compromise depends almost entirely on how quickly it is recognised and how appropriately it is escalated - most airway crises are made worse by delay or by persisting with a technique that has already failed, rather than by the underlying pathology being unmanageable. A structured assessment, anticipation of difficulty, and a clear plan for escalation and failure are what turn a potentially fatal airway emergency into a manageable one.