212 Acid-Base

Acidemia

A state where the arterial blood pH drops below the normal reference range (<7.35), indicating an increased concentration of hydrogen ions in the blood

Acidosis

A pathophysiologic process or condition that tends to cause an excess of acid or loss of base, driving body fluids toward a lower pH

Alkalemia

A state where the arterial blood pH rises above the normal reference range (>7.45), indicating a decreased concentration of hydrogen ions in the blood

Alkalosis

A pathophysiologic process or condition that tends to cause a deficit of acid or excess of base (bicarbonate), driving body fluids toward a higher pH

Anion gap

A calculated laboratory parameter derived from serum electrolyte measurements that assists in determining the specific underlying cause of metabolic acidosis

Buffering

The immediate chemical process by which body fluids resist large, rapid shifts in pH when acids or bases are added or removed

Buffers

Chemical pairs consisting of a weak acid and its conjugate base that immediately stabilize pH by binding excess hydrogen ions when fluid is too acidic or releasing hydrogen ions when fluid is too basic

Compensation

An adaptive physiological mechanism by which one organ system (lungs or kidneys) adjusts to counter an acid-base imbalance caused by the other system, moving blood pH back toward normal while leaving other chemical values abnormal

Correction

The definitive resolution of an acid-base disorder in which the primary organ responsible repairs the underlying defect, returning both blood pH and all blood gas values to their normal ranges

pH

The mathematical negative logarithm of the hydrogen ion concentration, serving as the clinical measure of acidity or alkalinity in body fluids

Respiratory acidosis

An acid-base disorder caused by alveolar hypoventilation and impaired pulmonary excretion of carbonic acid (CO2), resulting in an elevated PaCO2 and a decreased blood pH

Respiratory alkalosis

An acid-base disorder caused by alveolar hyperventilation and excessive excretion of carbonic acid CO2 by the lungs, resulting in a decreased PaCO2 and an elevated blood pH

Metabolic acidosis

An acid-base disorder characterized by an accumulation of metabolic acids or loss of bicarbonate base, resulting in a decreased serum bicarbonate (HCO3-) concentration and a decreased blood pH

Metabolic alkalosis

An acid-base disorder characterized by a deficit of metabolic acids or gain of bicarbonate base, resulting in an elevated serum bicarbonate (HCO3-) concentration and an elevated blood pH