Version 2.70

LP15429-1Base excessActive


LP15429-1   Base excess
Base excess refers to the amount of a strong acid required to bring back the blood pH to the normal value of 7.4. The term and concept were first introduced by Astrup and Siggaard-Andersen in 1958 as a way to measure the metabolic component of an acid-base disturbance.

Actual versus standard:
In vivo, acid-base homeostasis takes place throughout the extracellular fluid (ECF), not just the blood compartment that is in a patient specimen. The concept of "standard" base excess attempts to adjust for the base excess of the entire extracellular compartment by calculating the base excess for blood diluted as if the entire extracellular compartment were sampled (approx Hgb of 5g/l). So the ACTUAL base excess (ABE) is the dose of acid to return PLASMA to normal pH, whereas the STANDARD base excess (SBE) is the dose to return ECF to normal pH.

Adjusting for oxygen saturation:
Base excess normally assumes 100% oxygen saturation, which is valid for many arterial specimens. However, it is possible to add additional terms to the calculation which account for the actual oxygen saturation of the patient sample. The terms in LOINC indicating 'Base excess.100% oxygenated' are intended to encode base excess terms adjusted for oxygen saturation (i.e. do not assume 100% oxygenation). Source: Regenstrief LOINC

Basic Part Properties

Base excess
Created On
Construct for LOINC Short Name
Base excess

LOINC FHIR® API Example - CodeSystem Request Get Info


Language Variants Get Info

zh-CNChinese (China)
Synonyms: BE;BSE;碱超;碱过剩;过剩碱
nl-NLDutch (Netherlands)
et-EEEstonian (Estonia)
Aluste liig
fr-BEFrench (Belgium)
Excès de base
fr-CAFrench (Canada)
Excès de base
it-ITItalian (Italy)
Basi, eccesso
Synonyms: Eccesso di basi
ru-RURussian (Russian Federation)
Оснований избыток
es-ESSpanish (Spain)
Exceso de base
tr-TRTurkish (Turkey)
Baz fazlalığı