Summary

Acute upper airway obstruction is a life-threatening emergency where something blocks the passage of air through the throat, voice box, or windpipe—the critical "bottleneck" through which all air must pass. Think of it as a kink in a garden hose: even a small blockage can stop all flow. Unlike lower airway problems (like asthma), where you can still breathe but with difficulty, upper airway obstruction means you literally cannot get air in or out. The classic sign is stridor—a high-pitched, musical sound made when air is forced through a narrowed passage. Causes range from infections (epiglottitis, croup) to foreign bodies, allergic reactions, or trauma. This is a true "can't intubate, can't oxygenate" emergency where seconds count. Without immediate intervention (often intubation or emergency tracheostomy), complete obstruction leads to death within minutes.

Key Facts

• Definition: Blockage of airway above the level of the carina (tracheal bifurcation)
• Incidence: ~2-5% of emergency airway presentations; rare but critical
• Mortality: 5-10% if treated promptly; near 100% if untreated
• Time to intervention: Immediate—complete obstruction kills within 3-5 minutes
• Critical sign: Stridor (inspiratory = extrathoracic, expiratory = intrathoracic, biphasic = fixed)
• Key investigation: Clinical diagnosis (do not delay for imaging if severe)
• First-line treatment: Position, oxygen, prepare for intubation/tracheostomy

Clinical Pearls

"Stridor = Upper airway problem" — Stridor is the hallmark sign. If you hear it, think upper airway obstruction until proven otherwise. The sound tells you where the problem is: inspiratory = above vocal cords, expiratory = below, biphasic = fixed obstruction.

"If they can talk, they can breathe (for now)" — Ability to speak indicates some air movement. If they can only whisper or can't speak at all, obstruction is severe. Complete silence with no air movement = complete obstruction = immediate action needed.

"Don't lie them flat" — Sitting upright uses gravity to help keep the airway open. Lying flat can worsen obstruction, especially in conditions like epiglottitis or foreign body.

"If in doubt, secure the airway" — In suspected upper airway obstruction, it's better to intubate early (when it's easier) than wait until it's an emergency (when it's harder or impossible).

Why This Matters Clinically

Acute upper airway obstruction can kill within minutes if not recognized and treated. It's the classic airway emergency that every clinician must be prepared for. Unlike lower airway problems where you have time to think, upper airway obstruction requires immediate action. Delayed recognition or inappropriate management (like trying to visualize the airway in epiglottitis, which can cause complete obstruction) can be fatal. Rapid, protocol-driven management focusing on maintaining the airway while preparing for definitive management can save lives.

Structured Approach: ABCDE

A - Airway (Critical)

• Assessment: Is airway patent? Can patient speak?
• Look: Stridor, drooling, position, swelling
• Listen: Stridor (type: inspiratory, expiratory, biphasic)
• Feel: Swelling, crepitus (if trauma)
• Action:
  • If complete obstruction: Immediate intubation/tracheostomy
  • If severe: Prepare for intubation, do not delay
  • If moderate: Monitor closely, prepare for intervention

B - Breathing

• Look: Respiratory rate, use of accessory muscles, cyanosis
• Listen: Stridor, air entry (may be reduced)
• Feel: Chest expansion
• Measure: SpO2, respiratory rate
• Action: High-flow oxygen; consider intubation if severe

C - Circulation

• Look: Skin colour, capillary refill
• Feel: Pulse (rate, volume)
• Measure: BP, HR, ECG
• Action: IV access; treat hypotension if anaphylaxis

D - Disability

• Assessment: GCS, pupil response
• Finding: May be confused if hypoxic
• Action: Check glucose; consider if hypoxia causing confusion

E - Exposure

• Look: Full body examination, look for rash (anaphylaxis), trauma
• Feel: Swelling, crepitus
• Action: Identify cause if possible

Specific Examination Findings

Stridor Assessment:

Voice Assessment:

• Normal: Some obstruction but not at glottis
• Hoarse: Glottic involvement (vocal cords)
• Muffled: Supraglottic (epiglottitis - "hot potato voice")
• Whisper only: Severe glottic obstruction
• Unable to speak: Complete or near-complete obstruction

Swallowing Assessment:

• Normal: Can swallow saliva
• Difficulty: May drool occasionally
• Unable: Drooling constantly (severe obstruction, epiglottitis)

Position:

• Sitting upright: Uses gravity to help airway
• Leaning forward: Tries to open airway
• Tripod position: Hands on knees, leaning forward (severe distress)

Special Tests

CAUTION: Do NOT attempt to visualize the airway (e.g., with tongue depressor) in suspected epiglottitis—this can cause complete obstruction.

Natural History (Without Treatment)

Untreated Upper Airway Obstruction:

• Mortality: Near 100% if complete obstruction
• Progression: Rapid deterioration → complete obstruction → cardiac arrest
• Time course: Death within 3-5 minutes if complete obstruction

Outcomes with Treatment

Factors Affecting Outcomes:

Good Prognosis:

• Prompt recognition (<30 minutes)
• Early intervention (before complete obstruction)
• Reversible cause (anaphylaxis, croup)
• Expert airway management
• No underlying chronic condition

Poor Prognosis:

• Delayed recognition (>1 hour)
• Complete obstruction before treatment
• Underlying malignancy (tumors)
• Multiple comorbidities
• Failed intubation requiring surgical airway

Prognostic Factors

Key Guidelines

1. Difficult Airway Society Guidelines (2015) — UK guidelines for difficult airway management. British Journal of Anaesthesia

Key Recommendations:

• Rapid assessment of airway
• Prepare for difficult intubation
• Have surgical airway backup
• Evidence Level: 1A

2. ATLS Guidelines (2020) — Advanced Trauma Life Support for trauma-related airway issues. American College of Surgeons

Key Recommendations:

• Airway is priority in ABCDE
• Do not delay for imaging
• Have backup plans
• Evidence Level: 1A

3. Anaphylaxis Guidelines (2020) — World Allergy Organization guidelines. World Allergy Organization

Key Recommendations:

• IM adrenaline first-line
• Secure airway if not improving
• Evidence Level: 1A

Landmark Trials

Epiglottitis Management Study (1990s)

• Finding: Intubation reduces mortality from 20% to <1%
• Clinical Impact: Established intubation as standard
• PMID: Multiple studies

Evidence Strength

What is Acute Upper Airway Obstruction?

Imagine your throat as a narrow tunnel that air must pass through to reach your lungs. In acute upper airway obstruction, something blocks this tunnel—like a kink in a garden hose. Even a small blockage can stop all airflow. Unlike asthma (where the problem is in your lungs), this is in your throat or voice box, so you literally cannot get air in or out. The classic sign is stridor—a high-pitched, whistling sound when you try to breathe.

In simple terms: Something blocks your throat, making it impossible to breathe properly. This is a medical emergency that needs immediate treatment.

Why does it matter?

Acute upper airway obstruction can kill within minutes if not treated. Your body needs a constant supply of oxygen—without it, your brain and organs start to fail within 3-5 minutes. The good news? With immediate treatment (often a breathing tube inserted to bypass the blockage), most people recover completely.

Think of it like this: It's like someone holding your nose and mouth closed—you need help to breathe, and you need it fast.

How is it treated?

1. Immediate Support: Doctors give you extra oxygen and keep you sitting upright (lying flat can make it worse).

2. Breathing Tube: If the blockage is severe, doctors insert a breathing tube (intubation) through your mouth into your windpipe, bypassing the blockage. This is done under anaesthetic so you don't feel it.

3. Treating the Cause:

• If it's an infection: Antibiotics to treat the infection
• If it's an allergic reaction: Medicines to reduce swelling
• If it's a foreign body: Doctors remove it with a special scope

4. Surgery: Rarely, if a breathing tube can't be inserted, doctors may need to make a small opening in your neck (tracheostomy) to help you breathe.

The goal: Get air to your lungs immediately, then treat whatever is causing the blockage.

What to expect

In the Hospital:

• Immediate: Doctors will act quickly to secure your breathing
• First few hours: You'll be closely monitored, may have a breathing tube
• Days 1-2: If improving, doctors will remove the breathing tube when safe
• Days 3-5: Most people can go home if everything is healing

After Going Home:

• Recovery: Most people feel back to normal within days to weeks
• Voice: May be hoarse for a few days (from the breathing tube)
• Follow-up: Doctor visits to make sure everything is healing
• Prevention: Avoid triggers if it was an allergic reaction

Recovery Time:

• Breathing: Improves immediately once blockage is bypassed
• Voice: Usually back to normal within days to weeks
• Full recovery: 1-2 weeks for most people

When to seek help

Call 999 (or your emergency number) immediately if:

• You suddenly can't breathe
• You hear a whistling sound when breathing (stridor)
• You can't speak or can only whisper
• Your throat feels like it's closing
• You feel like you're suffocating
• Your lips or fingers turn blue

See your doctor urgently if:

• You have a sore throat that's getting worse quickly
• You're having trouble swallowing
• Your voice is getting hoarse
• You feel like something is stuck in your throat

Remember: If you suddenly can't breathe properly, especially if you hear a whistling sound, don't wait—get emergency help immediately. This can be life-threatening.

Conditions to Consider

Upper airway obstruction must be distinguished from other respiratory emergencies:

Clinical Differentiation

Stridor vs. Wheeze:

Upper vs. Lower Airway:

Mimics & Pitfalls

1. Vocal Cord Dysfunction:

• Clue: Paradoxical vocal cord motion (close on inspiration instead of opening)
• Key difference: No anatomical obstruction, laryngoscopy normal between episodes
• Investigation: Laryngoscopy (during episode if possible)
• Management: Speech therapy, reassurance, NOT intubation

2. Psychogenic Stridor (Functional Laryngeal Obstruction):

• Clue: Young patient, anxious, stridor that stops when distracted
• Key difference: Normal examination, normal SpO2, stops during sleep
• Investigation: Laryngoscopy (normal)
• Management: Reassurance, speech therapy, NOT intubation

3. Retropharyngeal Abscess (Don't Miss!):

• Clue: Posterior pharyngeal swelling, fever, drooling, neck stiffness
• Key: May mimic epiglottitis but swelling is behind
• Investigation: CT neck (lateral X-ray may show prevertebral swelling)
• Management: Surgical drainage + antibiotics + secure airway

4. Ludwig's Angina (Don't Miss!):

• Clue: Submandibular swelling, "wooden" floor of mouth, dental infection
• Key: Swelling elevates tongue, pushes it backward (blocks airway)
• Investigation: CT neck
• Management: Urgent surgical drainage + antibiotics + secure airway early

Primary Prevention

Vaccination Programs:

Foreign Body Prevention:

• Children: No small toys/foods for less than 3 years (choking hazards)
• Adults: Cut food into small pieces, chew thoroughly, avoid talking while eating
• Elderly: Careful eating if dentures or swallowing problems

Allergy Management:

• Known allergies: Avoid triggers, carry EpiPen
• Previous anaphylaxis: Wear medical alert bracelet
• Food allergies: Read labels carefully, inform restaurants

Secondary Prevention (After First Episode)

Post-Epiglottitis:

• Vaccination: Ensure up-to-date (Hib, pneumococcal)
• Follow-up: ENT review to ensure complete resolution
• Monitoring: Watch for recurrence

Post-Anaphylaxis:

• Allergy testing: Identify specific allergen
• Avoidance: Strict avoidance of trigger
• EpiPen: Carry at all times, teach family how to use
• Medical alert bracelet: Wear always
• Action plan: Written plan for what to do if exposure

Post-Foreign Body:

• Swallowing assessment: If recurrent, assess swallow function
• Education: Safe eating practices
• Monitoring: Watch for recurrence

Tertiary Prevention (High-Risk Groups)

Post-Radiation Patients:

• Risk: Laryngeal edema, stricture formation
• Monitoring: Regular ENT follow-up, laryngoscopy
• Early intervention: If symptoms develop

Chronic Conditions Increasing Risk:

Hospital Systems:

• Difficult airway registry: Document patients with known difficult airways
• Allergy alerts: Flagged in medical records
• Equipment availability: Airway carts available in all clinical areas

Paediatric Patients

Anatomical Differences:

• Narrower airway: Small changes cause big obstruction
• Cricoid ring: Narrowest point (vs. glottis in adults)
• Shorter neck: Less room to work
• Larger tongue: Relatively to airway size

Common Causes in Children:

Management Differences:

• Lower intubation threshold: Smaller airways = less reserve
• Smaller tube sizes: Age-appropriate sizing critical
• Parental involvement: Keep parents calm, involve in care
• Sedation: May need for procedures in cooperative children

Croup-Specific:

• Peak age: 6 months - 3 years
• Classic presentation: Barking cough, stridor, hoarse voice
• Treatment: Dexamethasone 0.15mg/kg PO/IV (single dose)
• Nebulized adrenaline: If severe (5ml of 1:1000)
• Intubation: Rarely needed (less than 5% of cases)

Elderly Patients (>75 Years)

Special Considerations:

Higher Risk Causes:

• Tumors: Head/neck cancer more common
• Post-operative complications: After ENT/thyroid surgery
• Aspiration: Neuromuscular problems, stroke
• Iatrogenic: Post-radiation, post-surgical

Management Adjustments:

• Lower threshold for airway security: Less physiological reserve
• Careful medication dosing: Renal/hepatic impairment common
• Early goals of care discussion: If very frail or terminal disease
• Multidisciplinary approach: Geriatrics, palliative care if appropriate

Pregnant Women

Physiological Changes:

• Airway edema: Increased from 2nd trimester (hormonal)
• Reduced reserve: Lower FRC (functional residual capacity)
• Difficult intubation: 2-3x higher risk than non-pregnant
• Rapid desaturation: Less oxygen reserve

Management Considerations:

• Left lateral tilt: If supine (prevents aorto-caval compression)
• Smaller tube: May need due to airway edema
• Difficult airway preparation: Have backup plans ready
• Fetal monitoring: If viable (>24 weeks)
• Obstetrics involvement: Always involve in care

Causes:

• Anaphylaxis: Same as non-pregnant
• Epiglottitis: Rare but can occur
• Angioedema: May be exacerbated by pregnancy
• Pre-eclampsia/eclampsia: Can cause laryngeal edema

Patients with Tracheostomy

Special Considerations:

• Bypass upper airway: Obstruction above tracheostomy not problematic
• Tracheostomy obstruction: Can occur (mucus plug, tube displacement)
• Emergency management:
  • Remove inner tube
  • Suction
  • Replace tube if needed
  • Ventilate through stoma if cannot replace

Assessment:

• Check tracheostomy first: Before assuming upper airway problem
• Cuff inflation: Check cuff if applicable
• Tube position: Ensure not displaced

Patients with Head/Neck Cancer

Challenges:

• Distorted anatomy: Tumor or post-surgical
• Radiation changes: Fibrosis, edema
• Difficult intubation: Often very difficult
• Bleeding risk: Tumor erosion into vessels

Management Approach:

• Early ENT involvement: Essential
• Awake intubation: Often needed
• Video laryngoscopy: Helps with visualization
• Low threshold for tracheostomy: May be safest option
• Bleeding control: Have equipment ready

Prevention:

• Regular monitoring: ENT clinic follow-up
• Early imaging: If symptoms develop
• Prophylactic tracheostomy: Consider if high risk

Obese Patients

Challenges:

• Difficult intubation: Anatomical challenges
• Rapid desaturation: Lower oxygen reserve
• Positioning: Difficult to position for intubation
• Equipment: May need specialist equipment

Management Adjustments:

• Preoxygenation: Crucial (desaturate faster)
• Ramped position: Head elevated 30° for intubation
• Video laryngoscopy: Often helpful
• Two-person technique: May be needed
• Have backup plans: Surgical airway equipment ready

Last Reviewed: 2025-12-24 | MedVellum Editorial Team

Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists. This information is not a substitute for professional medical advice, diagnosis, or treatment.