Definition of Respiratory acidosis:

Respiratory acidosis is a condition that occurs when the lungs cannot remove all of the carbon dioxide the body produces. This disrupts the body's acid-base balance causing body fluids, especially the blood, to become too acidic.

Causes, incidence, and risk factors:

Causes of respiratory acidosis include:

• Diseases of the airways (such as asthma and chronic obstructive lung disease), which send air into and out of the lungs
• Diseases of the chest (such as sarcoidosis), which make the lungs less efficient at filling and emptying
• Diseases affecting the nerves and muscles that "signal" the lungs to inflate or deflate
• Drugs that suppress breathing (including powerful pain medicines, such as narcotics, and "downers," such as benzodiazepines), especially when combined with alcohol
• Severe obesity, which restricts how much the lungs can expand

Chronic respiratory acidosis occurs over a long period of time. This leads to a stable situation, because the kidneys increase body chemicals, such as bicarbonate, that help restore the body's acid-base balance.

Acute respiratory acidosis is a severe condition in which carbon dioxide builds up very quickly and before the kidneys can return the body to a state of balance.

Symptoms:

Symptoms may include:

• Confusion
• Easy fatigue
• Lethargy
• Shortness of breath
• Sleepiness

Signs and tests:

• Arterial blood gas (measures levels of oxygen and carbon dioxide in the blood; in respiratory acidosis, the level of carbon dioxide is too high)
• Chest x-ray
• Pulmonary function test

Treatment:

Treatment is aimed at the underlying lung disease, and may include:

• Bronchodilator drugs to reverse some types of airway obstruction
• Noninvasive positive-pressure ventilation (sometimes called CPAP or BiPAP) or mechanical ventilation if needed
• Oxygen if the blood oxygen level is low
• Treatment to stop smoking

Expectations (prognosis):

How well you do depends on the disease causing the respiratory acidosis.

Complications:

• Poor organ function
• Respiratory failure
• Shock

Calling your health care provider:

Severe respiratory acidosis is a medical emergency. Seek immediate medical help if you have symptoms of this condition.

Call your health care provider if you have symptoms of lung disease.

Prevention:

Do not smoke. Smoking leads to the development of many severe lung diseases that can cause respiratory acidosis.

Losing weight may help prevent respiratory acidosis due to obesity (obesity-hypoventilation syndrome).

Be careful about taking sedating medicines, and never combine these medicines with alcohol.