base excess


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base ex·cess

a measure of metabolic alkalosis, usually predicted from the Siggaard-Andersen nomogram; the amount of strong acid that would have to be added per unit volume of whole blood to titrate it to pH 7.4 while at 37°C and at a carbon dioxide pressure of 40 mmHg.

base excess

a measure of metabolic alkalosis or metabolic acidosis (negative value of base excess) expressed as the amount of acid or alkali needed to titrate 1 L of fully oxygenated blood to a pH of 7.40, the temperature being held at a constant 37° C and the PCO2 at 40 mm Hg.

base excess

A measure of the nonrespiratory buffers—bicarbonate, haemoglobin, proteins—in blood.

BE refers to a deviation of the buffer base (BB) from normal BB, and is the amount of base in fully oxygenated blood (which is zero at pH 7.4, the normal base value of the blood); it is equal to the amount of a strong acid or base needed to bring the pH in blood to 7.4 at a pCO2 of 40 mmHg—5.3 kPa at 37ºC. The presence of base excess suggests metabolic alkalosis; a base deficit suggests metabolic acidosis. It is defined by the equation BE = actual BB – normal BB.

base ex·cess

(bās eks'es)
A measure of metabolic alkalosis; the amount of strong acid that would have to be added per unit volume of whole blood to titrate it to pH 7.4 while at 37°C and at a carbon dioxide pressure of 40 mmHg.

base

1. the lowest part or foundation of anything. See also basis.
2. the main ingredient of a compound.
3. a molecule or ion with a tendency to take up a proton according to Bronsted and Lowry theory; a substance that combines with acids to form salts. In the chemical processes of the body, bases are essential to the maintenance of a normal acid-base balance. Excessive concentration of bases in the body fluids leads to alkalosis. See also basal.
4. the primary entity against which all other entities are compared.
5. the non-sugar components of nucleotides in DNA and RNA.

acid-base pairs
the two molecules forming the matching acid and conjugate base.
base composition
refers to the relative components of a nucleic acid.
conjugate base
the anion or uncharged molecule of an acid once it has given up its proton, e.g. Cl is the conjugate base of the acid, HCl.
base deficit
see base excess (below).
base excess
the amount of acid or base required to titrate a sample of whole arterial blood to the normal pH of 7.4. The base excess is determined mathematically by calculations that include measurement of the blood Pco2 and pH and take into account the hemoglobin level. It is negative (base deficit) in acidosis and positive in alkalosis.
heart base
the wide dorsal part of the heart carrying the atria and the large blood vessels and the attachment to the pericardial sac.
horn base
the widest part of the horn, at its attachment to the skin. In the adult horned animal the horn is hollow at this point, encloses the horn process of the frontal bone and merges with the skin. This is covered with a thin layer of horn similar to the periople of the hoof, called the epiceras.
narrow base
a mandible which is narrow relative to the maxilla; often causes the lower canine teeth to strike the hard palate. See also anisognathism.
nitrogenous base
an aromatic, nitrogen-containing molecule that serves as a proton acceptor, e.g. purine or pyrimidine.
omasal base
faces cranially and to the left where it is attached to the reticulum and the abomasum at the reticulo-omasal and omasoabomasal orifices.
base pair
two hydrogen bonded nucleotides in a DNA or RNA molecule.
purine b's
a group of compounds of which purine is the base, including uric acid, adenine, guanine, xanthine and theobromine.
pyrimidine b's
a group of chemical compounds of which pyrimidine is the base, including uracil, thymine and cytosine, which are common constituents of nucleic acids.
stapedal base
the footplate of the stapes in the middle ear from which the two legs originate. The stapes lies horizontally with the base facing medially and attached to the vestibular window by the annular ligament.
References in periodicals archive ?
For those neonates with metabolic acidosis, cord arterial blood isoprostane concentrations and base excess showed a linear relationship, suggesting that oxidative stress plays a role in a significant proportion of cases with hypoxic-ischemic encephalopathy.
0 or a base excess of -12 or higher in cord or venous blood taken from newborns within 60 min of birth, or the need for resuscitation at birth and/or for positive pressure ventilation (>3 min) (15).
Last year, Diametrics Medical introduced a test cartridge that measures blood pH, carbon dioxide (pCO2) and oxygen (pO2) and also calculates bicarbonate (HCO3), total carbon dioxide (TCO2), base excess in blood (BEb), base excess in extra cellular fluid (BEecf) and oxygen saturation (O2SAT).
Instead, an unchanged base excess of extracellular fluid more simply and accurately would demonstrate the absence of a metabolic component.