O. Siggaardandersen et Ih. Gothgen, OXYGEN AND ACID-BASE PARAMETERS OF ARTERIAL AND MIXED VENOUS-BLOOD, RELEVANT VERSUS REDUNDANT, Acta anaesthesiologica Scandinavica, 39, 1995, pp. 21-27
A complete pH and blood gas analysis of arterial and mixed venous bloo
d may comprise more than forty different quantities. We have selected
sixteen, including patient temperature. The arterial oxygen tension gr
oup includes the oxygen tension, fraction of oxygen in inspired air, a
nd fraction of mixed venous blood in the arterial (total physiological
veno-arterial shunting). The haemoglobin oxygen capacity group includ
es effective haemoglobin concentration and fractions of carboxy- and m
ethaemoglobin. The haemoglobin oxygen affinity group includes half-sat
uration tension and estimated 2,3-diphosphoglycerate concentration of
erythrocytes. In a neonatal care unit fraction of fetal haemoglobin ne
eds to be included. The arterial oxygen extractivity is measured as th
e oxygen extraction tension, which indicates the degree of compensatio
n among the oxygen tension, capacity, and affinity. The mixed venous g
roup includes mixed venous oxygen tension, and, when measured, cardiac
output, and oxygen consumption rate. The acid-base status includes bl
ood pH, arterial carbon dioxide tension, and extracellular base excess
. Other quantities such as haemoglobin oxygen saturation, respiratory
index, total oxygen concentration (oxygen content), oxygen extraction
fraction, oxygen delivery, and several others, provide no essential ad
ditional clinical information and are therefore redundant.