Respiratory acidosis

  • Definition
    • Respiratory acidosis is a condition that occurs when the lungs cannot remove all of the carbon dioxide the body produces. This causes body fluids, especially the blood, to become too acidic.

  • Alternative Names
    • Ventilatory failure; Respiratory failure; Acidosis - respiratory

  • Causes
    • Causes of respiratory acidosis include:

      • Diseases of the airways (such as asthma and chronic obstructive lung disease)
      • Diseases of the chest (such as scoliosis)
      • 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
      • Obstructive sleep apnea

      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 condition in which carbon dioxide builds up very quickly, before the kidneys can return the body to a state of balance.

      Some people with chronic respiratory acidosis get acute respiratory acidosis because an illness makes their condition worse.

  • Symptoms
    • Symptoms may include:

      • Confusion
      • Easy fatigue
      • Lethargy
      • Shortness of breath
      • Sleepiness
  • Exams and Tests
    • The health care provider will perform a physical exam. Tests that may be done include:

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

      • Bronchodilator drugs to reverse some types of airway obstruction
      • Noninvasive positive-pressure ventilation (sometimes called CPAP or BiPAP) or a breathing machine, if needed
      • Oxygen if the blood oxygen level is low
      • Treatment to stop smoking
  • Outlook (Prognosis)
    • How well you do depends on the disease causing the respiratory acidosis.

  • Possible Complications
      • Poor organ function
      • Respiratory failure
      • Shock
  • When to Contact a Medical Professional
    • 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 that suddenly get worse.

  • 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.

  • References
    • Effros RM, Swenson ER. Acid-base balance. In: Mason RJ, Broaddus CV, Martin TR, et al. Murray & Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, PA: Elsevier Saunders; 2010:chap 7.

      Seifter JL. Acid-base disorders. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 120.