When the lungs can no longer maintain adequate oxygen levels or clear enough carbon dioxide, respiratory failure begins. The brain tolerates 5 to 7 minutes without oxygen before irreversible damage and the trajectory from laboured breathing to unconsciousness can be fast. Pneumonia, COPD (chronic obstructive pulmonary disease), asthma, heart failure, and acute lung injury can all converge on the same emergency. At CARE Hospitals, the respiratory team assesses oxygen saturation, arterial blood gases, and airway status on arrival and escalates to ventilatory support without delay.

What is Respiratory Failure?

Respiratory failure is defined by what blood gas measurements reveal. When arterial oxygen tension (PaO2) falls below 60 mmHg, carbon dioxide tension (PaCO2) rises above 50 mmHg or both thresholds are crossed. This shows that the lungs are no longer adequately performing their job: the blood is not being oxygenated properly, and carbon dioxide is not being cleared. The two main types of respiratory failure are:

• Type 1 (hypoxaemic respiratory failure): Represented as low oxygen levels and normal or low CO2 levels. In this the lungs cannot transfer oxygen despite adequate breathing effort. Common causes are pneumonia, pulmonary embolism (blood clot in the lung), pulmonary oedema (fluid in the lung) and ARDS (acute respiratory distress syndrome). 
• Type 2 (hypercapnic respiratory failure): Characterised by low oxygen with raised CO2. This occurs when the breathing mechanism fails to remove carbon dioxide effectively. Common causes include COPD exacerbation, severe asthma, neuromuscular disease and sedative drug overdose.

Common Causes of Respiratory Failure

Any condition impairing oxygen transfer, breathing mechanics, or respiratory drive can cause respiratory failure. They are:

• Pneumonia: The bacterial infection fills lung tissue with pus, blocking oxygen transfer across the alveolar membrane (the thin wall of the air sacs)
• COPD exacerbation: Flare triggered by infection or pollution; already-damaged airways narrow further, trapping air and causing CO2 to accumulate (Type 2 failure)
• Acute severe asthma: Severe airway narrowing (bronchospasm) can significantly restrict airflow and impair breathing 
• Pulmonary embolism: A blood clot in the pulmonary arteries blocks blood flow to part of the lung, reducing oxygenation despite intact lung tissue
• Pulmonary oedema: Fluid accumulation in the lungs (due to heart failure or ARDS) interferes with oxygen exchange 
• Neuromuscular disease: Guillain-Barré syndrome, myasthenia gravis, motor neurone disease, or cervical cord injury paralysing the breathing muscles
• Drug or alcohol overdose: Opioids (heroin, morphine, fentanyl) and benzodiazepines suppress the brainstem's respiratory centre, causing hypoventilation (dangerously slow, shallow breathing)
• Pneumothorax: Air entering the pleural space (between the lung and the chest wall) collapses the lung, leading to respiratory distress.

Signs and Symptoms of Respiratory Failure

Symptoms reflect the degree of hypoxia (low oxygen) and hypercapnia (raised CO2):

• Severe breathlessness: Breathlessness at rest including being unable to complete a sentence
• Rapid breathing: Respiratory rate above 25 breaths per minute (normal is 12 to 20)
• Increased breathing effort: Use of accessory muscles, including neck (sternocleidomastoid), intercostal, and abdominal muscles to help with breathing 
• Chest wall retractions: Skin retraction above the sternum (breastbone) or between the ribs during inhalation
• Cynosis: Blue-grey discolouration of lips and fingernails 
• Paradoxical breathing: Abdomen moves outward as chest moves inward; a sign of diaphragmatic fatigue or airway obstruction
• Confusion, agitation or drowsiness: Hypoxia reduces brain function
• Rapid heart rate and excessive sweating: Common signs of the body's response to inadequate oxygen delivery
• Low oxygen saturation (SpO₂): SpO2 below 92% and below 88% in COPD patients on controlled oxygen
• Slow or irregular breathing: A sign of severe respiratory failure; seen in drug overdose, neurological conditions, or impending respiratory arrest.

First Aid for Respiratory Failure (Before Reaching Hospital)

Respiratory failure requires emergency care and home management is supportive only:

• Call emergency services immediately: Do not drive a severely breathless patient to the hospital. Paramedics carry oxygen, nebulisers and airway equipment. Tell the dispatcher the patient cannot complete sentences.
• Position upright: Sit upright or lean forward with hands on the knees (tripod position) - this reduces the work of the diaphragm. Never lay a conscious, breathless patient flat.
• Give prescribed reliever medication: For asthma or COPD, give the prescribed short-acting bronchodilator up to 10 puffs via a spacer, one puff every 30 seconds. Repeat every 15 to 20 minutes while waiting.
• Loosen clothing: Tight clothing around the neck, chest or abdomen restricts breathing. Loosen or remove anything constricting.
• If the patient becomes unconscious: Place the patient in the recovery position (on their side). If not breathing, begin CPR immediately.
• Do not give oxygen without prescription in COPD: In known COPD, uncontrolled high flow oxygen suppresses respiratory drive and worsens CO2 retention. Wait for paramedics with controlled-flow equipment.

When to Seek Emergency Care for Respiratory Failure

All require immediate ambulance response.

• Breathlessness at rest & cannot speak in full sentences
• Respiratory rate above 25 or below 10 breaths per minute
• Oxygen saturation below 92% on pulse oximetry
• Visible use of neck or rib muscles to breathe
• Cyanosis (blue lips or fingernails)
• Confusion, agitation, or drowsiness in a breathless patient
• Asthma attack not responding after two doses of reliever inhaler
• Sudden severe breathlessness with chest pain
• Unconscious patient or very slow breathing.

Emergency Treatment at the Hospital for Respiratory Failure

Your doctor will initiate the treatment with finding the cause. They also support oxygen delivery to vital organs:

• Oxygen therapy: The emergency team delivers controlled oxygen to maintain SpO2 between 94 and 98% (88 and 92% in COPD). 
• Non invasive ventilation (NIV): For Type 2 failure from COPD or pulmonary oedema, BiPAP (bilevel positive airway pressure) clears CO2 and reduces breathing effort without intubation. CPAP (continuous positive airway pressure) keeps your air sacs open if you have pulmonary oedema.
• Intubation and mechanical ventilation: When NIV fails or the patient is unconscious the doctors perform rapid sequence intubation (RSI) - sedation plus muscle relaxant followed by endotracheal intubation (tube through the mouth into the windpipe) & mechanical ventilation. Lung protective ventilation uses a tidal volume of 6 ml/kg of ideal body weight to prevent pressure injury.
• Cause specific treatment:
  • Pneumonia: IV antibiotics within one hour. 
  • COPD: Nebulised bronchodilators, steroids & controlled oxygen. 
  • Pulmonary embolism: IV heparin and thrombolysis (alteplase) for massive PE with collapse. 
  • Asthma: Intensive bronchodilator therapy and intravenous magnesium sulphate. 
  • Tension pneumothorax: Needle decompression then chest drain. 
  • Opioid overdose: IV naloxone to reverse the effects of opioids.
• Arterial blood gas monitoring: Repeated ABG (arterial blood gas) measurements from the radial artery track PaO2, PaCO2, and pH (blood acidity) to confirm treatment response. 

What Not to Do

These actions delay treatment or worsen the patient's condition:

• Do not lay a conscious breathless patient flat as the supine position worsens distress and raises aspiration risk
• Do not give uncontrolled high flow oxygen in known COPD 
• Do not delay calling emergency services as respiratory failure can deteriorate from compensated to pre-arrest in minutes
• Do not rely on consumer phone oximeters as they can be inaccurate; clinical assessment and ABG are the standard.

Conclusion

Respiratory failure carries high mortality without rapid, correctly targeted treatment. Oxygen, correct positioning, cause-specific treatment, and escalation to NIV or mechanical ventilation must happen in minutes. At CARE Hospitals, ABG and airway status are assessed from arrival, NIV and intubation are escalated when indicated and pulmonology and critical care are involved without delay.

FAQs

1. What are the warning signs of respiratory failure?

Warning signs are:

• Breathlessness at rest preventing full sentences
• Respiratory rate above 25 or below 10
• Visible neck or rib muscle use 
• Blue lips or fingernails
• Confusion or drowsiness alongside breathing difficulty.

2. When is breathing difficulty considered an emergency?

When it occurs at rest, fails to respond to prescribed reliever medication within 15 to 20 minutes, or is accompanied by confusion, cyanosis (blue lips), or very slow breathing - all are considered emergencies.

3. Can respiratory failure become life-threatening?

Yes hypoxia (low oxygen) causes irreversible brain damage within five to seven minutes; rising CO2 causes narcosis (toxicity and unconsciousness); both are immediately life threatening without ventilatory support.

4. What should I do if someone is struggling to breathe?

Call emergency services, sit them upright in the tripod position (leaning forward with hands on knees), give prescribed reliever medication, loosen tight clothing, and begin CPR if they stop breathing.

5. How is respiratory failure diagnosed?

ABG (arterial blood gas) is definitive - PaO2 below 60 mmHg confirms hypoxaemia, PaCO2 above 50 mmHg confirms hypercapnia. Pulse oximetry, chest X-ray and clinical assessment diagnose respiratory failure. 

6. Can pneumonia lead to respiratory failure?

Severe pneumonia causes Type 1 respiratory failure by filling lung tissue with pus and fluid, blocking oxygen transfer. Community-acquired pneumonia requiring ICU care carries a high risk of respiratory failure and ARDS (the most severe lung injury) develops in many hospitalised pneumonia patients.

CARE Medical Team