Respiratory alkalosis

Respiratory alkalosis
Davenport diagram outlines pH and bicarbonate levels
Classification and external resources
Specialty	endocrinology
ICD-10	E87.3
ICD-9-CM	276.3
DiseasesDB	406
MedlinePlus	000111
eMedicine	med/2009
MeSH	D000472

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][2] This condition is one of the four basic categories of disruption of acid-base homeostasis.

Classification

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.^[3][4]

• Acute respiratory alkalosis occurs rapidly, have a high pH because the response of the kidneys is slow.^[5]
• Chronic respiratory alkalosis is a more long-standing condition, here one finds the kidneys have time to decrease the bicarbonate level.^[5]

Terminology

• Alkalosis refers to the process due to which there is elevation of blood pH.^[6]
• Alkalemia refers to an arterial blood pH of greater than 7.45.^[7]

Signs and symptoms

	PVC (a type of palpitation) recording An audio clip recording of a PVC symptom, made with a cardiac event monitor.
Problems playing this file? See media help.

Signs and symptoms of respiratory alkalosis are as follows:^[8]

• Palpitation
• Tetany
• Convulsion
• Sweating

Causes

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

• Stress^[1]
• Pulmonary disorder^[4]
• Thermal insult^[9]
• High altitude areas^[6]
• Salicylate poisoning (aspirin overdose) ^[6]
• Fever^[1]
• Hyperventilation (due to heart disorder or other)^[1][10]
• Vocal cord paralysis (compensation for loss of vocal volume results in over-breathing/breathlessness).^[11]
• Liver disease^[6]

Mechanism

Carbonic-acid

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: ${\rm {HCO_{3}^{-}+H^{+}\rightarrow H_{2}CO_{3}\rightarrow CO_{2}+H_{2}O}}$ This causes decreased circulating hydrogen ion concentration, and increased pH (alkalosis).^[12][13]

Diagnosis

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^[14]

Treatment

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.^[4] If the individual is on a mechanical ventilator then preventing hyperventilation is done via monitoring ABG levels.^[15]

Society

In The Andromeda Strain, one of the characters is exposed to contamination, but saves himself by increasing his breathing rhythm until he has respiratory alkalosis in his blood.^[16]

See also

• Acidosis
• Alkalosis
• Arterial blood gas
• Chemical equilibrium
• Hypocalcemia
• Metabolic acidosis
• Metabolic alkalosis
• pCO2
• pH
• pKa
• Respiratory acidosis

References

1. "Respiratory alkalosis: MedlinePlus Medical Encyclopedia". www.nlm.nih.gov. Retrieved 2016-02-12.
2. 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.
3. Adrogué, HJ; Madias, NE (June 2010). "Secondary responses to altered acid-base status: the rules of engagement.". Journal of the American Society of Nephrology : JASN. 21 (6): 920–3. doi:10.1681/ASN.2009121211. PMID 20431042.
4. "Respiratory Alkalosis: Background, Pathophysiology, Epidemiology".
5. Metheny, Norma M. (2011-01-07). Fluid and Electrolyte Balance. Jones & Bartlett Publishers. p. 148. ISBN 9780763781644.
6. "Alkalosis: MedlinePlus Medical Encyclopedia". www.nlm.nih.gov. Retrieved 2016-02-12.
7. Klingensmith, Mary E. (2015-10-28). The Washington Manual of Surgery. Lippincott Williams & Wilkins. p. 87. ISBN 9781496310798.
8. Porth, Carol (2011-01-01). Essentials of Pathophysiology: Concepts of Altered Health States. Lippincott Williams & Wilkins. p. 205. ISBN 9781582557243.
9. Feld, Leonard G.; Kaskel, Frederick J. (2009-12-15). Fluid and Electrolytes in Pediatrics: A Comprehensive Handbook. Springer Science & Business. p. 280. ISBN 9781603272254.
10. https://www.nlm.nih.gov/medlineplus/ency/article/003071.htm
11. "Medscape: Medscape Access". medscape.com.
12. "Evaluation of respiratory alkalosis". us.bestpractice.bmj.com. Retrieved 2016-02-12.
13. Wilkins, Lippincott Williams & (2005-01-01). Pathophysiology: A 2-in-1 Reference for Nurses. Lippincott Williams & Wilkins. p. 102. ISBN 9781582553177.
14. Albert, Richard K.; Spiro, Stephen G.; Jett, James R. (2008-01-01). Clinical Respiratory Medicine. Elsevier Health Sciences. p. 128. ISBN 0323048250.
15. Handbook of Medical-surgical Nursing. Lippincott Williams & Wilkins. 2006-01-01. p. 801. ISBN 9781582554457.
16. http://www.afi.com/wise/films/andromeda_strain/androm.html

Further reading

• Lang, Florian (2009-03-19). Encyclopedia of Molecular Mechanisms of Disease: With 213 Tables. Springer Science & Business Media. ISBN 9783540671367.
• Unwin, R.; Stidwell, R.; Taylor, S.; Capasso, G. (1997-11-01). "The effects of respiratory alkalosis and acidosis on net bicarbonate flux along the rat loop of Henle in vivo". American Journal of Physiology - Renal Physiology. 273 (5): F698–F705. ISSN 1931-857X. PMID 9374832.
• LeBlanc, P J; Parolin, M L; Jones, N L; Heigenhauser, G J F (2002-10-01). "Effects of respiratory alkalosis on human skeletal muscle metabolism at the onset of submaximal exercise". The Journal of Physiology. 544 (Pt 1): 303–313. doi:10.1113/jphysiol.2002.022764. ISSN 0022-3751. PMC 2290561. PMID 12356901.