The anion gap is used to aid in the differential diagnosis of metabolic acidosis. In medicine, differential diagnosis (sometimes abbreviated DDx or ΔΔ) is the systematic method physicians use to identify the disease causing a patients symptoms. ... In medicine, metabolic acidosis is a state in which the blood pH is low (under 7. ...

Calculation

It is calculated by subtracting the serum concentrations of chloride and bicarbonate (anions) from the concentrations of sodium plus potassium (cations): The chloride ion is formed when the element chlorine picks up one electron to form an anion (negatively-charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. ... In inorganic chemistry, a bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. ... ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Standard atomic weight 22. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Standard atomic weight 39. ... An ion is an atom or group of atoms with a net electric charge. ...

 = ( [Na+]+[K+] ) - ( [Cl-]+[HCO3-] ) 

However, for daily practice, the potassium is frequently ignored, leaving the following equation:

 = ( [Na+] ) - ( [Cl-]+[HCO3-] ) 

Uses

The anion gap is representative of the unmeasured anions in the plasma, and these anions are affected differently based on the type of metabolic acidosis. The primary function of the anion gap measurement is to allow a clinician to narrow down the possible causes of a patients metabolic acidosis. For example, if a patient presents with metabolic acidosis, but a normal anion gap, then conditions that cause a high anion gap can be ruled out as being the cause of the acidosis.

Normal value ranges

In the past, methods for the measurement of the anion gap consisted of colorimetry for [HCO₃^-] and [Cl^-] as well as flame photometry for [Na⁺] and [K⁺]. Thus normal reference values ranged from 8 to 16 mmol/L plasma when not including [K⁺] and from 10 and 20 mmol/L plasma when including [K⁺]. Some specific sources use 15^[1] and 8-16 mEq/L.^[2][3] A colorimeter is a device used to measure the absorbance of a specific solution. ...

Modern analysers make use of ion-selective electrodes which give a normal anion gap as <11 mmol/L. Therefore according to the new classification system a high anion gap is anything above 11mmol/L and a normal anion gap is between 3-11 mmol/L.^[4]

Interpretation and causes

Anion gap can be classified as either high, normal or, in rare cases, low. A high anion gap indicates that there is loss of HCO₃^- without a subsequent increase in Cl^-. Electroneutrality is maintained by the increased production of anions like ketones, lactate, PO₄^-, and SO₄^-; these anions are not part of the anion-gap calculation and therefore a high anion gap results. In patients with a normal anion gap the drop in HCO₃^- is compensated for by an increase in Cl^- and hence is also known as hyperchloremic acidosis. Ketone group A ketone(key tone) is either the functional group characterized by a carbonyl group (O=C) linked to two other carbon atoms or a chemical compound that contains this functional group. ... Lactic acid is a chemical compound that plays a role in several biochemical processes. ... Hyperchloremic acidosis is a form of metabolic acidosis associated with a normal anion gap, a decrease in plasma bicarbonate concentration, and in increase in plasma chloride concentration. ...

High anion gap

The bicarbonate lost is replaced by an unmeasurable anion and thus you will see a high anion gap.

• Lactic acidosis
• Ketoacidosis
  • Diabetic ketoacidosis
  • Alcohol abuse

• Toxins:
  • Ethanol
  • Ethylene glycol
  • Lactic acid
  • Methanol
  • Paraldehyde
  • Aspirin
  • Cyanide, coupled with elevated venous oxygenation
  • Iron
  • isoniazid

The mnemonic "MUDPILES" is used to remember the causes of a high anion gap. Lactic acidosis is a condition caused by the buildup of lactic acid in the body. ... Ketoacidosis is a type of metabolic acidosis which is caused by high concentrations of keto acids, formed by the deamination of amino acids. ... Diabetic ketoacidosis (DKA) is a life-threatening complication in patients with untreated diabetes mellitus (chronic high blood sugar or hyperglycemia). ... Alcoholism is the consumption of, or preoccupation with, alcoholic beverages to the extent that this behavior interferes with the drinkers normal personal, family, social, or work life, and may lead to physical or mental harm. ... Grain alcohol redirects here. ... Ethylene glycol (monoethylene glycol (MEG), IUPAC name: ethane-1,2-diol) is an alcohol with two -OH groups (a diol), a chemical compound widely used as an automotive antifreeze. ... Lactic acid (IUPAC systematic name: 2-hydroxypropanoic acid), also known as milk acid, is a chemical compound that plays a role in several biochemical processes. ... Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naptha or wood spirits, is a chemical compound with chemical formula CH3OH. It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid with a distinctive odor that is somewhat milder and sweeter than ethanol (ethyl alcohol). ... Paraldehyde is the cyclic form of three acetaldehyde molecules (a trimer). ... Aspirin or acetylsalicylic acid (acetosal) is a drug in the family of salicylates, often used as an analgesic (against minor pains and aches), antipyretic (against fever), and anti-inflammatory. ... The cyanide ion, CN−. From the top: 1. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... Isoniazid (also called isonicotinyl hydrazine or isonicotinic acid hydrazide); abbreviated INH or just H. Isoniazid is a first-line antituberculous medication used in the prevention and treatment of tuberculosis. ...

M - methanol
U - uremia
D - diabetic ketoacidosis
P - paraldehyde or phenformin
I - iron or isoniazid
L - lactate
E - ethylene glycol
S - salicylates Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naptha or wood spirits, is a chemical compound with chemical formula CH3OH. It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid with a distinctive odor that is somewhat milder and sweeter than ethanol (ethyl alcohol). ... Uremia is a toxic condition resulting from renal failure, when kidney function is compromised and urea, a waste product normally excreted in the urine, is retained in the blood. ... Diabetic ketoacidosis (DKA) is a life-threatening complication in patients with untreated diabetes mellitus (chronic high blood sugar or hyperglycemia). ... Paraldehyde is the cyclic form of three acetaldehyde molecules (a trimer). ... Phenformin is an anti-diabetic drug from the biguanide class. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... Isoniazid (also called isonicotinyl hydrazine or isonicotinic acid hydrazide); abbreviated INH or just H. Isoniazid is a first-line antituberculous medication used in the prevention and treatment of tuberculosis. ... Lactic acid is a chemical compound that plays a role in several biochemical processes. ... Ethylene glycol (monoethylene glycol (MEG), IUPAC name: ethane-1,2-diol) is an alcohol with two -OH groups (a diol), a chemical compound widely used as an automotive antifreeze. ... Salicylic acid is a colorless, crystalline organic carboxylic acid. ...

Normal anion gap (hyperchloremic acidosis)

Usually the HCO₃^- lost is replaced by a chloride anion, and thus there is a normal anion gap. Hyperchloremic acidosis is a form of metabolic acidosis associated with a normal anion gap, a decrease in plasma bicarbonate concentration, and in increase in plasma chloride concentration. ...

• Gastrointestinal loss of HCO₃^- (i.e. diarrhea) (note: vomiting causes hypochloraemic alkalosis)
• Renal loss of HCO₃^- (i.e. proximal renal tubular acidosis)
• Renal dysfunction (i.e. renal failure, hypoaldosteronism, distal renal tubular acidosis)
• Ingestions
  • Ammonium chloride and Acetazolamide.
  • Hyperalimentation fluids (i.e. total parenteral nutrition)
• Some cases of ketoacidosis, particularly during insulin treatment

• Alcohol (such as ethanol) can effect anion gap by inducing alcohol dehydrogenase enzyme.

For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and... Types 5-7 on the Bristol Stool Chart are often associated with diarrhea Diarrhea (in American English) or diarrhoea (in British English) is a generally unpleasant condition in which the sufferer has frequent watery, loose bowel movements (from the Greek word διάρροια; literally meaning through-flowing). Acute infectious diarrhea is a... Kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... Renal tubular acidosis, or RTA, is a medical condition in which the kidneys fail to dispose of a normal amount of acid into the urine, which may lead to acidosis (where the blood becomes too acidic). ... Kidneys viewed from behind with spine removed The kidneys are bean-shaped excretory organs in vertebrates. ... Renal failure is the condition in which the kidneys fail to function properly. ... In medicine (endocrinology), hypoaldosteronism refers to decreased levels of the hormone aldosterone. ... Renal tubular acidosis, or RTA, is a medical condition in which the kidneys fail to dispose of a normal amount of acid into the urine, which may lead to acidosis (where the blood becomes too acidic). ... Ammonium chloride or Sal Ammoniac (chemically ammonium chloride (NH4Cl); also nushadir salt, zalmiak, sal armagnac, sal armoniac, salmiakki, salmiak and salt armoniack) is, in its pure form, a clear white water-soluble crystalline salt with a biting taste. ... Hyperalimentation is a procedure in which nutrients and vitamins are given to a person in liquid form through a vein. ... Total parenteral nutrition (TPN), is the practice of feeding a person intravenously, circumventing the gut. ... Ketoacidosis is a type of metabolic acidosis which is caused by high concentrations of keto acids, formed by the deamination of amino acids. ... Insulin (from Latin insula, island, as it is produced in the Islets of Langerhans in the pancreas) is a polypeptide hormone that regulates carbohydrate metabolism. ... Alcohol Dehydrogenase Alcohol dehydrogenases are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones. ...

Low anion gap

A low anion gap is relatively rare but may occur from the presence of abnormal positively charged proteins, as in multiple myeloma, or in the setting of a low serum albumin level. It has been suggested that this article or section be merged into serum albumin. ...

References

In 1828 the Medical Academy of Georgia was chartered by the state of Georgia with plans to offer a single course of lectures leading to a bachelors degree. ...

External links

• Clinical Physiology of Acid-Base and Electrolyte Disorders by Rose, Post
• Intensive Care Medicine by Irwin and Rippe
• The ICU Book by Marino
• Calculator at mcw.edu