By anoxemia is meant a condition in which the oxygen pressure in the systemic capillaries is abnormally diminished.1 It is seen most frequently when the hemoglobin of the blood is less saturated with oxygen than normally. The difference between the amount of oxygen which the hemoglobin is capable of carrying (oxygen capacity) and the amount which it actually carries (oxygen content) is known as the oxygen unsaturation of the blood.
In normal adults Lundsgaard2 found that the unsaturation of the venous blood varies from 2.7 to 9.0 c.c. of oxygen for each hundred cubic centimeters of blood, averaging 5.8 c.c. Our results with blood obtained from the longitudinal sinus of well infants (Table 1) are practically the same as those of Lundsgaard on blood from the median basilic vein of adults. The oxygen unsaturation varied from 5.1 to 8.3 c.c., averaging 6.7 c.c. Blood from a scalp vein