Respiratory Failure

How breathing normally works

The lungs bring oxygen into the blood and remove carbon dioxide. This depends on:

• the brain's breathing center sending signals
• nerves and breathing muscles (especially the diaphragm) working
• open airways
• healthy air sacs and blood flow in the lungs

A problem at any point can lead to respiratory failure.

Types of respiratory failure

Respiratory failure is also described by timing:

• acute: develops over minutes to days, a medical emergency
• chronic: develops over months to years, the body partly adapts
• acute-on-chronic: sudden worsening of chronic failure, for example during a COPD flare

Symptoms

• severe shortness of breath and air hunger
• fast or, in some cases, slow and shallow breathing
• using neck and chest muscles to breathe
• bluish lips or fingertips (cyanosis)
• fast heart rate
• restlessness, anxiety, confusion
• drowsiness, which can progress to coma with high carbon dioxide
• morning headaches and poor sleep in chronic hypercapnia

Causes

Lung and airway diseases

• pneumonia, including COVID-19 and influenza
• acute respiratory distress syndrome
• COPD and severe asthma attacks
• pulmonary fibrosis and other interstitial lung diseases
• cystic fibrosis

Heart and blood vessels

• heart failure causing fluid on the lungs
• pulmonary embolism

Brain, nerves and muscles

• opioid, sedative or alcohol overdose
• stroke and head injury
• amyotrophic lateral sclerosis, myasthenia gravis, Guillain-Barré syndrome, muscular dystrophy, spinal cord injury

Chest wall and other causes

• severe obesity
• scoliosis or chest injuries such as rib fractures
• sepsis
• smoke inhalation and carbon monoxide poisoning (which affects oxygen delivery)

Diagnosis

• pulse oximetry to measure oxygen saturation
• arterial or venous blood gas to measure oxygen, carbon dioxide and acidity
• chest X-ray or CT to look for pneumonia, fluid, collapse or clots
• ECG and echocardiogram for heart causes
• blood tests for infection, heart strain and drug levels
• lung function and sleep studies for chronic respiratory failure

Treatment

Oxygen

Supplemental oxygen through nasal prongs, masks or high-flow nasal cannula raises blood oxygen. In people with COPD and chronic CO2 retention, oxygen is given carefully to a target range (often 88 to 92 percent) to avoid worsening CO2 levels.

Breathing support

• Noninvasive ventilation (BiPAP): a tight-fitting mask that assists each breath. Very effective in COPD flares and heart failure, and used at home for chronic hypercapnic failure from obesity or neuromuscular disease.
• Mechanical ventilation: a breathing tube connected to a ventilator in intensive care when other support is not enough.
• ECMO: a machine that oxygenates blood outside the body, used in specialized centers for the most severe cases.

Treat the cause

• antibiotics or antivirals for infection
• bronchodilators and steroids for asthma and COPD
• diuretics for heart failure
• blood thinners for pulmonary embolism
• naloxone for opioid overdose
• immune treatments for myasthenia gravis or Guillain-Barré syndrome

Chronic respiratory failure

• long-term home oxygen
• home noninvasive ventilation
• pulmonary rehabilitation
• vaccinations against flu, COVID-19, pneumococcus and RSV
• advance care planning conversations

Outlook

Outcomes depend on the cause, age and overall health. Many people recover from acute respiratory failure caused by a treatable illness, though recovery after a long ICU stay can take months, with weakness, fatigue and memory problems. Chronic respiratory failure can often be managed for years with home oxygen and ventilation.

Frequently asked questions

What are the signs of respiratory failure?

Signs include severe shortness of breath, fast breathing, struggling to speak, blue or gray lips, confusion, and unusual drowsiness. Someone with these signs needs emergency care immediately.

What is the difference between type 1 and type 2 respiratory failure?

Type 1 means blood oxygen is too low, usually from lung problems like pneumonia or ARDS. Type 2 means carbon dioxide is too high because breathing is not moving enough air, as in COPD, opioid overdose or muscle weakness.

What causes respiratory failure?

Common causes are pneumonia, COPD, asthma, heart failure, pulmonary embolism, ARDS, opioid overdose, obesity and neuromuscular diseases such as ALS or myasthenia gravis. Anything affecting the lungs, airways, breathing muscles or brain's breathing control can cause it.

Can you recover from respiratory failure?

Yes, many people recover, especially when the cause is treatable, such as pneumonia or an asthma attack. Recovery after intensive care can take weeks to months. Chronic respiratory failure is usually managed long-term rather than cured.

Is respiratory failure the same as ARDS?

No. Respiratory failure is a broad term for the lungs failing to maintain normal oxygen or carbon dioxide levels. ARDS is one specific, severe cause of type 1 respiratory failure, involving widespread inflammation of both lungs.