The area under the curve of L-lactate in neonatal foals from birth to 14 days of age.

Abstract

Prior studies have shown the prognostic utility of measuring L-lactate in critically ill neonatal foals, both as single (at admission) and serial measurements. Greater prognostic sensitivity and specificity may be achieved by use of the area under the L-lactate versus time curve (LACArea ) over the first 24 hours of hospitalization, which captures both severity and duration of hyperlactatemia. Prior to application of this concept in sick equine neonates, a reference interval for LACArea should be determined. The concentration of lactate [LAC] was measured in blood obtained via direct jugular venipuncture from clinically normal foals on Days 1 (birth-24 h of age), 3, 7, and 14 following birth at 6-hour intervals for each 24-hour period. LACArea was calculated using the trapezoidal method. Differences in LACArea by Day were determined by MANOVA with a priori Bonferroni correction, P ≤ 0.05. LACArea differed by Day (P = 0.001), being largest on Day 1, followed by Day 3. Days 7 and 14 were smallest and not different from each other. LACArea decreases substantially and predictably over the first week of life in normal neonatal foals. Knowing how LACArea normally changes over the first 2 weeks of life will aid in future study of LACArea as it applies to sick neonatal foals, allowing for consideration of maturational changes potentially unrelated to disease.