Alkalosis
Encyclopedia
Alkalosis refers to a condition reducing hydrogen ion
concentration of arterial
blood plasma
(alkalemia). Generally, alkalosis is said to occur when pH
of the blood exceeds 7.45. The opposite condition is acidosis
(when pH falls below 7.35).
, resulting in a loss of carbon dioxide
. Compensatory mechanisms for this would include increased dissociation of the carbonic acid
buffering intermediate into hydrogen ion
s, and the related excretion of bicarbonate
, both of which would raise, not lower, blood pH
.
Metabolic alkalosis can be caused by prolonged vomiting, resulting in a loss of hydrochloric acid
with the stomach content. Severe dehydration
, and the consumption of alkali are other causes. It can also be caused by administration of diuretics and endocrine disorders such as Cushing's syndrome
. Compensatory mechanism for metabolic alkalosis involve slowed breathing by the lungs to increase serum carbon dioxide, a condition leaning toward respiratory acidosis
. As respiratory acidosis often accompanies the compensation for metabolic alkalosis, and vice versa, a delicate balance is created between these two conditions.
, causing, e.g., muscular weakness, myalgia
, and muscle cramps (owing to disturbed function of the skeletal muscles), and muscle spasms(from disturbed function of smooth muscles).
It may also cause hypocalcemia. As the pH of blood increases, the protein in the blood becomes more ionised into anions. This causes the free calcium present in blood to bind strongly with protein. If severe, it may cause tetany
(alkalotic tetany).
Hydrogen ion
Hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes.Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions....
concentration of arterial
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
blood plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
(alkalemia). Generally, alkalosis is said to occur when pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
of the blood exceeds 7.45. The opposite condition is acidosis
Acidosis
Acidosis is an increased acidity in the blood and other body tissue . If not further qualified, it usually refers to acidity of the blood plasma....
(when pH falls below 7.35).
Causes
The main cause of respiratory alkalosis is hyperventilationHyperventilation
Hyperventilation or overbreathing is the state of breathing faster or deeper than normal, causing excessive expulsion of circulating carbon dioxide. It can result from a psychological state such as a panic attack, from a physiological condition such as metabolic acidosis, can be brought about by...
, resulting in a loss of carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
. Compensatory mechanisms for this would include increased dissociation of the carbonic acid
Carbonic acid
Carbonic acid is the inorganic compound with the formula H2CO3 . It is also a name sometimes given to solutions of carbon dioxide in water, because such solutions contain small amounts of H2CO3. Carbonic acid forms two kinds of salts, the carbonates and the bicarbonates...
buffering intermediate into hydrogen ion
Hydrogen ion
Hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes.Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions....
s, and the related excretion of bicarbonate
Bicarbonate
In inorganic chemistry, bicarbonate is an intermediate form in the deprotonation of carbonic acid...
, both of which would raise, not lower, blood pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
.
Metabolic alkalosis can be caused by prolonged vomiting, resulting in a loss of hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
with the stomach content. Severe dehydration
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
, and the consumption of alkali are other causes. It can also be caused by administration of diuretics and endocrine disorders such as Cushing's syndrome
Cushing's syndrome
Cushing's syndrome is a hormone disorder caused by high levels of cortisol in the blood. This can be caused by taking glucocorticoid drugs, or by tumors that produce cortisol or adrenocorticotropic hormone or CRH...
. Compensatory mechanism for metabolic alkalosis involve slowed breathing by the lungs to increase serum carbon dioxide, a condition leaning toward respiratory acidosis
Acidosis
Acidosis is an increased acidity in the blood and other body tissue . If not further qualified, it usually refers to acidity of the blood plasma....
. As respiratory acidosis often accompanies the compensation for metabolic alkalosis, and vice versa, a delicate balance is created between these two conditions.
Complications
Metabolic alkalosis is usually accompanied with hypokalemiaHypokalemia
Hypokalemia or hypokalaemia , also hypopotassemia or hypopotassaemia , refers to the condition in which the concentration of potassium in the blood is low...
, causing, e.g., muscular weakness, myalgia
Myalgia
Myalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
, and muscle cramps (owing to disturbed function of the skeletal muscles), and muscle spasms(from disturbed function of smooth muscles).
It may also cause hypocalcemia. As the pH of blood increases, the protein in the blood becomes more ionised into anions. This causes the free calcium present in blood to bind strongly with protein. If severe, it may cause tetany
Tetany
Tetany has two meanings, though both are related to the muscular system.* Tetany * Tetany The terms "tetany" and "tetanus" are distinct....
(alkalotic tetany).
See also
- AcidosisAcidosisAcidosis is an increased acidity in the blood and other body tissue . If not further qualified, it usually refers to acidity of the blood plasma....
- Acid-base physiology
- Acid-base homeostasisAcid-base homeostasisAcid–base homeostasis is the part of human homeostasis concerning the proper balance between acids and bases, in other words, the pH. The body is very sensitive to its pH level, so strong mechanisms exist to maintain it...
- milk-alkali syndromeMilk-alkali syndromeIn medicine, milk-alkali syndrome, also called Burnett's syndrome in honour of Charles Hoyt Burnett, the American physician who first described it, is characterized by hypercalcemia caused by repeated ingestion of calcium and absorbable alkali...
- Mixed disorder of acid-base balance