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Introduction to Airway Management

8 min read

Why the airway comes first

In emergency medicine, the ABCs — Airway, Breathing, Circulation — are not a mnemonic convenience. They are a priority sequence based on a physiological fact: a patient can survive minutes without circulation, but only seconds to minutes without a patent airway. Everything else — IV access, medications, imaging, definitive treatment — is irrelevant if the patient cannot move air.

This is not because the airway is more complex than other organ systems. It is because the airway is the bottleneck. The cardiovascular system can only deliver oxygen the respiratory system has acquired. The respiratory system can only acquire oxygen the airway allows to pass. A blocked airway makes every downstream system fail simultaneously.

Two things that are not the same thing

Airway management requires distinguishing between two processes that are easy to confuse:

Oxygenation — getting oxygen into the blood. Measured by pulse oximetry (SpO2). When oxygenation fails, the patient becomes hypoxic — cells cannot generate energy, and organ damage follows within minutes.

Ventilation — moving gas in and out of the lungs, which removes carbon dioxide. Measured by capnography (end-tidal CO2). When ventilation fails, CO2 accumulates, blood becomes acidotic, and eventually the brainstem’s respiratory drive is overwhelmed.

These can fail independently. A patient on supplemental oxygen may maintain adequate oxygenation while ventilation deteriorates — they have enough oxygen in reserve to mask the fact that they are not moving air effectively. Pulse oximetry will read normal until the oxygen reserve is consumed, at which point desaturation is rapid and precipitous. This is why capnography matters: it detects ventilation failure before oximetry does.

The clinical error this distinction prevents: treating a ventilation problem with more oxygen. If a patient is not moving air (obstructed airway, depressed respiratory drive, exhausted respiratory muscles), increasing the concentration of oxygen they are not moving does not solve the problem. They need the airway opened, or they need mechanical ventilation — someone or something to move the air for them.

The airway as anatomy

The airway is a continuous tube from the nose and mouth to the alveoli. Clinically, it divides into upper and lower:

Upper airway (nose, mouth, pharynx, larynx): Where obstruction is most common and most immediately life-threatening. The tongue is the most frequent cause of upper airway obstruction in an unconscious patient — it falls posteriorly under gravity when muscle tone is lost. This is why the most basic airway intervention is positioning: head-tilt/chin-lift or jaw thrust lifts the tongue off the posterior pharyngeal wall.

Lower airway (trachea, bronchi, bronchioles): Where bronchospasm (asthma, COPD exacerbation), secretions, and edema produce obstruction. Lower airway obstruction typically presents with wheezing and prolonged expiration — air can get in but has difficulty getting out through narrowed airways.

The sound tells you the level: stridor (a harsh inspiratory sound) suggests upper airway narrowing. Wheezing (a musical expiratory sound) suggests lower airway narrowing. Silence — no air movement despite effort — suggests complete obstruction and is the most dangerous sign.

Staged escalation

Airway management follows a principle of staged escalation: start with the simplest effective intervention and escalate only as needed.

  1. Positioning and basic maneuvers — head-tilt/chin-lift, jaw thrust, recovery position. These cost nothing, require no equipment, and solve the most common cause of obstruction (tongue displacement) immediately.

  2. Supplemental oxygen — nasal cannula, face mask, non-rebreather. These address oxygenation but not ventilation. They buy time.

  3. Airway adjuncts — oropharyngeal airway (OPA), nasopharyngeal airway (NPA). These maintain a physical channel past the tongue. They assist positioning, not ventilation.

  4. Positive-pressure ventilation — bag-valve-mask (BVM) ventilation. This is the first intervention that actively moves air for the patient. It requires skill — a good mask seal, appropriate rate and volume, and awareness of gastric insufflation risk.

  5. Advanced airway — endotracheal intubation or supraglottic airway device. These provide a definitive (intubation) or rescue (supraglottic) airway. They require training, equipment, and ideally a plan for what happens if the first attempt fails.

The principle is not “always intubate.” The principle is “use the least invasive intervention that maintains oxygenation and ventilation while you address the underlying cause.” A patient with anaphylaxis needs epinephrine — the pharmacological intervention treats the cause while airway management buys time for the drug to work.

Children are not small adults

Pediatric airways differ from adult airways in ways that change management:

  • Larger occiput — the child’s head naturally flexes the neck forward, potentially occluding the airway. Positioning requires a pad under the shoulders, not the head.
  • Larger tongue relative to oral cavity — more prone to obstruction, less room for instruments.
  • More anterior and cephalad larynx — harder to visualize during intubation.
  • Narrowest point at the cricoid ring (subglottic), not the vocal cords — means a tube that passes the cords may still be too large, and subglottic edema (as in croup) produces dramatic obstruction in a small-diameter airway.
  • Lower oxygen reserve, higher metabolic rate — children desaturate faster than adults. The margin for error is smaller.

These are not complications. They are the baseline anatomy. Managing a pediatric airway without accounting for these differences is managing a different patient’s anatomy.

After the tube: the work continues

Post-intubation management is where errors quietly accumulate:

  • Confirm placement — capnography (persistent end-tidal CO2 waveform) is the gold standard. A tube in the esophagus ventilates the stomach, not the lungs. This kills patients.
  • Secure the tube — an unintentionally dislodged endotracheal tube is an emergency created by the intervention.
  • Post-intubation hypotension — common and multifactorial: positive-pressure ventilation reduces venous return, sedation drops sympathetic tone, and the underlying condition may be worsening. Anticipate it.
  • Sedation and analgesia — an awake, paralyzed patient is a preventable catastrophe. Adequate sedation and pain control are not optional.

Self-check

1. A patient has a pulse oximetry reading of 98% but is breathing only 6 times per minute with shallow breaths. Are they in danger? Why or why not?

Yes, they are in danger. The pulse oximetry reading reflects oxygenation, which may be maintained temporarily by supplemental oxygen or oxygen reserves. But the low respiratory rate and shallow breaths indicate ventilation failure — they are not moving enough air to clear CO2. Carbon dioxide is accumulating, blood pH is dropping, and eventually respiratory drive will be lost entirely. Capnography would show rising end-tidal CO2. This patient needs ventilatory support (bag-valve-mask ventilation or intervention to restore respiratory drive), not just more oxygen. The normal SpO2 is masking a ventilation crisis.

2. You hear stridor in a patient with a swollen face after a bee sting. Using the staged escalation framework, what do you do?

This is anaphylaxis — upper airway edema (indicated by stridor) with a known trigger. The staged escalation framework says to support the airway while treating the cause. Immediate actions: (1) Administer epinephrine intramuscularly — this is the pharmacological intervention that treats the underlying anaphylaxis by reversing bronchospasm and reducing edema. (2) Position the patient upright if conscious, supine with legs elevated if hypotensive. (3) Provide supplemental oxygen. (4) Prepare for escalation: if stridor worsens or the patient cannot maintain the airway, have BVM, airway adjuncts, and intubation equipment ready. (5) Call for help early — anaphylaxis can deteriorate rapidly, and a surgical airway may be needed if edema prevents intubation. The key insight: epinephrine treats the cause; airway management buys time for the drug to work.

3. Why is the distinction between oxygenation and ventilation particularly important in opioid overdose?

Opioids cause respiratory depression — they suppress the brainstem’s respiratory drive, producing slow, shallow breathing (hypoventilation). This is a ventilation problem first: the patient stops moving air effectively, CO2 accumulates. Oxygenation may initially be maintained because the patient still has some oxygen reserve. Giving supplemental oxygen (addressing oxygenation) without addressing ventilation will temporarily maintain SpO2 but does not solve the problem — the patient is still not clearing CO2 and will eventually arrest. The correct interventions address ventilation: naloxone (pharmacological reversal of the opioid’s effect on respiratory drive) and, if naloxone is not immediately available or the patient is not breathing, bag-valve-mask ventilation (mechanically moving air for the patient). This connects directly to pharmacology: naloxone is a competitive antagonist at the mu-opioid receptor, with a shorter half-life than most opioids — which is why ventilatory support and monitoring must continue after naloxone administration.

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