Preliminary investigation of the area under the L-lactate concentration-time curve (LACArea) in critically ill equine neonates.

BACKGROUND: A variety of measures of L-lactate concentration ([LAC]) in the blood of critically ill neonatal foals have shown utility as prognostic indicators. These measures, evaluating either the severity of hyperlactatemia or the duration of exposure to hyperlactatemia, perform fairly well and have correctly classified 75-80% of foals examined in several studies. The area under the L-lactate concentration versus time curve (LACArea) encompasses both severity and duration of hyperlactatemia and should improve correct classification of patient survival. HYPOTHESIS/OBJECTIVES: LACArea is larger in nonsurviving critically ill neonatal foals. ANIMALS: Forty-nine foals admitted for critical illness to 1 of 4 referral hospitals. METHODS: Whole blood was obtained at admission and 6, 12, 18, and 24 hours after admission for measurement of L-lactate using a handheld lactate meter. LACArea was calculated for: admission-6, 6-12, 12-18, 18-24 hours, and admission-24 hours using the trapezoidal method and summing the 6-hours interval areas to determine total 24 hours area. Differences between survivors and nonsurvivors were determined using robust regression and Kruskal-Wallis testing, P < .05. RESULTS: LACArea was significantly larger in nonsurviving foals (n = 9) than in surviving foals (n = 40) at all time periods examined. CONCLUSIONS AND CLINICAL IMPORTANCE: Differences in LACArea between surviving and nonsurviving critically ill neonatal foals are large and support further investigation of this method as an improved biomarker for survival in critically ill neonatal foals is indicated.

Pharmacokinetics and adverse effects of oral meloxicam tablets in healthy adult horses.

The objective of this study was to assess the pharmacokinetic profile and determine whether any adverse effects would occur in seven healthy adult horses following oral meloxicam tablet administration once daily for 14 days at a dose of 0.6 mg/kg·bwt. Horses were evaluated for health using physical examination, complete blood count, serum chemistry, urinalysis, and gastroscopy at the beginning and end of the study. Blood was collected for the quantification of meloxicam concentrations with liquid chromatography and mass spectrometry. The mean terminal half-life was 4.99 ± 1.11 h. There was no significant difference between the mean Cmax , 1.58 ± 0.71 ng/mL at Tmax 3.48 ± 3.30 h on day 1, 2.07 ± 0.94 ng/mL at Tmax 1.24 ± 1.24 h on day 7, and 1.81 ± 0.76 ng/mL at 1.93 ± 1.30 h on day 14 (P = 0.30). There was a statistically significant difference between the Tmax on the sample days (P = 0.04). No statistically significant increase in gastric ulcer score or laboratory analytes was noted. Oral meloxicam tablets were absorbed in adult horses, and adverse effects were not statistically significant in this study. Further studies should evaluate the adverse effects and efficacy of meloxicam tablets in a larger population of horses before routine use can be recommended.