Anioniväli

Anioniväli, often translated as anion gap, is a laboratory measurement used in medicine to help differentiate between different causes of metabolic acidosis. It is calculated by subtracting the measured concentrations of chloride and bicarbonate from the measured concentration of sodium in the blood. The formula is typically represented as: Anion Gap = [Sodium] - ([Chloride] + [Bicarbonate]).

The anion gap represents the unmeasured anions in the plasma, which primarily include negatively charged proteins like albumin, phosphates, and sulfates. A normal anion gap generally falls within a specific reference range, which can vary slightly between laboratories. An elevated anion gap suggests the presence of an increased amount of unmeasured anions, indicating that the metabolic acidosis is likely due to the accumulation of acids other than hydrochloric acid. Common causes of a high anion gap metabolic acidosis include ketoacidosis (diabetic or alcoholic), lactic acidosis, and certain intoxications with substances like methanol, ethylene glycol, or salicylates.

A normal or low anion gap in the setting of metabolic acidosis points to a different etiology, often referred to as a normal anion gap metabolic acidosis or hyperchloremic acidosis. This typically arises from a loss of bicarbonate or an inability of the kidneys to excrete acid. Examples include diarrhea, renal tubular acidosis, and certain medications like acetazolamide. Monitoring the anion gap alongside other electrolytes and acid-base parameters is a crucial diagnostic tool for clinicians managing patients with metabolic disturbances.