Respiratory alkalosis is a medical condition in which increased respiration elevates the blood pH beyond the normal range (7.35–7.45) with a concurrent reduction in arterial levels of carbon dioxide.[1][4] This condition is one of the four primary disturbance of acid–base homeostasis.[5]

Respiratory alkalosis
Other namesAlkalosis - respiratory[1]
Davenport diagram outlines pH and bicarbonate levels
SpecialtyPulmonology, Anaesthesia
SymptomsTetany, palpitation[2]
CausesHyperventilation,[1] Pulmonary disorder[3]
Diagnostic methodChest x-ray, Pulmonary function tests[1]
TreatmentDetect underlying cause[1]

Signs and symptoms


Signs and symptoms of respiratory alkalosis are as follows:[2]



Respiratory alkalosis may be produced as a result of the following causes:



The mechanism of respiratory alkalosis generally occurs when some stimulus makes a person hyperventilate. The increased breathing produces increased alveolar respiration, expelling CO2 from the circulation. This alters the dynamic chemical equilibrium of carbon dioxide in the circulatory system. Circulating hydrogen ions and bicarbonate are shifted through the carbonic acid (H2CO3) intermediate to make more CO2 via the enzyme carbonic anhydrase according to the following reaction:  

This causes decreased circulating hydrogen ion concentration, and increased pH (alkalosis).[10][11]



The diagnosis of respiratory alkalosis is done via test that measure the oxygen and carbon dioxide levels (in the blood), chest x-ray and a pulmonary function test of the individual.[1]

The Davenport diagram allows clinicians or investigators to outline blood bicarbonate concentrations (and blood pH) after a respiratory or metabolic acid-base disturbance[12]



There are two types of respiratory alkalosis: chronic and acute as a result of the 3–5 day delay in kidney compensation of the abnormality.[13][3]

  • Acute respiratory alkalosis occurs rapidly, have a high pH because the response of the kidneys is slow.[14]
  • Chronic respiratory alkalosis is a more long-standing condition, here one finds the kidneys have time to decrease the bicarbonate level.[14]
  • Alkalosis refers to the process due to which there is elevation of blood pH.[7]
  • Alkalemia refers to an arterial blood pH of greater than 7.45.[15]



Respiratory alkalosis is very rarely life-threatening, though pH level should not be 7.5 or greater. The aim in treatment is to detect the underlying cause. When PaCO2 is adjusted rapidly in individuals with chronic respiratory alkalosis, metabolic acidosis may occur.[3] If the individual is on a mechanical ventilator then preventing hyperventilation is done via monitoring ABG levels.[16]


In The Andromeda Strain, one of the characters is exposed to contamination, but saves himself by increasing his respiratory rate to induce alkalosis.[17]

See also



  1. ^ a b c d e f g h i "Respiratory alkalosis: MedlinePlus Medical Encyclopedia". Archived from the original on 2016-07-05. Retrieved 2016-02-12.
  2. ^ a b Porth, Carol (2011-01-01). Essentials of Pathophysiology: Concepts of Altered Health States. Lippincott Williams & Wilkins. p. 205. ISBN 9781582557243. Archived from the original on 2024-05-19. Retrieved 2016-02-12.
  3. ^ a b c d "Respiratory Alkalosis: Background, Pathophysiology, Epidemiology". 2018-10-04. Archived from the original on 2020-03-02. Retrieved 2016-02-12. {{cite journal}}: Cite journal requires |journal= (help)
  4. ^ Singh, Virendra; Khatana, Shruti; Gupta, Pranav (2013-01-01). "Blood gas analysis for bedside diagnosis". National Journal of Maxillofacial Surgery. 4 (2): 136–141. doi:10.4103/0975-5950.127641. ISSN 0975-5950. PMC 3961885. PMID 24665166.
  5. ^ "The Four Primary Disturbances of Acid-Base Balance". Archived from the original on 2024-05-19. Retrieved 2022-06-10.
  6. ^ Feld, Leonard G.; Kaskel, Frederick J. (2009-12-15). Fluid and Electrolytes in Pediatrics: A Comprehensive Handbook. Springer Science & Business. p. 280. ISBN 9781603272254. Archived from the original on 2024-05-19. Retrieved 2016-02-12.
  7. ^ a b c d "Alkalosis: MedlinePlus Medical Encyclopedia". Archived from the original on 2024-05-19. Retrieved 2016-02-12.
  8. ^ "Hyperventilation: MedlinePlus Medical Encyclopedia". Archived from the original on 2016-02-17. Retrieved 2016-02-12.
  9. ^ "Medscape: Medscape Access". Medscape. 2018-04-05. Archived from the original on 2015-05-08. Retrieved 2015-05-11.
  10. ^ "Evaluation of respiratory alkalosis". Archived from the original on 2016-02-15. Retrieved 2016-02-12.
  11. ^ Wilkins, Lippincott Williams & (2005-01-01). Pathophysiology: A 2-in-1 Reference for Nurses. Lippincott Williams & Wilkins. p. 102. ISBN 9781582553177. Archived from the original on 2024-05-19. Retrieved 2016-02-12.
  12. ^ Albert, Richard K.; Spiro, Stephen G.; Jett, James R. (2008-01-01). Clinical Respiratory Medicine. Elsevier Health Sciences. p. 128. ISBN 978-0323048255. Archived from the original on 2024-05-19. Retrieved 2016-02-12.
  13. ^ Adrogué, HJ; Madias, NE (June 2010). "Secondary responses to altered acid-base status: the rules of engagement". Journal of the American Society of Nephrology. 21 (6): 920–3. doi:10.1681/ASN.2009121211. PMID 20431042.
  14. ^ a b Metheny, Norma M. (2011-01-07). Fluid and Electrolyte Balance. Jones & Bartlett Publishers. p. 148. ISBN 9780763781644. Archived from the original on 2024-05-19. Retrieved 2016-02-12.
  15. ^ Klingensmith, Mary E. (2015-10-28). The Washington Manual of Surgery. Lippincott Williams & Wilkins. p. 87. ISBN 9781496310798. Archived from the original on 2024-05-19. Retrieved 2016-02-12.
  16. ^ Handbook of Medical-surgical Nursing. Lippincott Williams & Wilkins. 2006-01-01. p. 801. ISBN 9781582554457.
  17. ^ "AFI: Robert Wise – Andromeda Strain". Archived from the original on 2019-08-26.

Further reading