1 Department of Pediatrics and Aerospace Medical Laboratory (Clinical), Aerospace Medical Laboratory (AFSC), Wilford Hall USAF Hospital, Lackland Air Force Base, Texas
The effect of 5 to 20 minutes of mild to moderate activity on the concentration of blood lactate in 9 infants was measured. During activity the concentration of blood lactate increased 0.4 to 1.8 mM/L. The maximum increase in the concentration of blood lactate after vigorous activity was 2.9 mM/L.
Based on the results of these studies, the following conclusions are drawn:
1. Activity, even if mild, can increase significantly the concentration of blood lactate in the neonate.
2. During vigorous activity, lactate can accumulate at rates (0.14-0.34 mM/L/min) approaching those observed during total asphyxia.
3. Following activity, neonates may metabolize lactate at a slower rate than human adults.
4. The effect of activity must be considered in the interpretation of any studies which involve the concentration of blood lactate in the neonate.
Submitted on June 30, 1964