Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
Department of Cardiac Surgery, Faculty of Medical Sciences, Ghent University, Ghent, Belgium.
Vet Med Sci. 2023 Jul;9(4):1534-1540. doi: 10.1002/vms3.1148. Epub 2023 May 4.
Activated clotting times (ACTs) are used to screen for coagulopathies and monitor heparin therapy.
To determine a reference interval (RI) for ACT in dogs using a point-of-care analyser, to quantify intra-subject within- and between-day variability, to quantify analyser reliability and inter-analyser agreement and to study the influence of a delay in measurement.
Forty-two healthy dogs were included. Measurements were performed on fresh venous blood using the i-STAT 1 analyser. The RI was determined using the Robust method. Intra-subject within-day variability and between-day variability were quantified between baseline and 2 h (n = 8) or 48 h (n = 10) later. Analyser reliability and inter-analyser agreement were studied by duplicate measurements (n = 8) on identical analysers. The influence of measurement delay was studied before and after a delay of one analytical run (n = 6).
Mean, lower and upper reference limits for ACT were 92.9 ± 9.1, 74.4 and 111.2 s, respectively. Coefficients of variation of intra-subject within- and between-day variability were 8.1% and 10.4%, respectively, resulting in a significant between-day measurement difference. Analyser reliability assessed by the intraclass correlation coefficient and coefficient of variation were 0.87% and 3.3%, respectively. Significantly lower ACT values were observed after a measurement delay compared to direct analysis.
Our study provides an RI for ACT in healthy dogs using the i-STAT 1 and suggests low intra-subject within- and between-day variability. Analyser reliability and inter-analyser agreement were good; however, analysis delay and between-day differences could significantly influence ACT results.
激活凝血时间（ACT）用于筛查凝血障碍和监测肝素治疗。
使用即时检验（POC）分析仪确定犬的 ACT 参考区间（RI），量化个体内日内和日间变异性，量化分析仪的可靠性和分析间一致性，并研究测量延迟的影响。
纳入 42 只健康犬。使用 i-STAT 1 分析仪对新鲜静脉血进行测量。使用稳健法确定 RI。在基线和 2 小时（n=8）或 48 小时（n=10）后，量化个体内日内和日间变异性。通过在相同的分析仪上重复测量（n=8）研究分析仪的可靠性和分析间一致性。研究测量延迟对结果的影响，即在一个分析运行之前和之后进行测量（n=6）。
ACT 的平均值、下限和上限参考限值分别为 92.9±9.1、74.4 和 111.2 s。个体内日内和日间变异性的变异系数分别为 8.1%和 10.4%，导致日间测量差异具有统计学意义。通过组内相关系数和变异系数评估的分析仪可靠性分别为 0.87%和 3.3%。与直接分析相比，测量延迟后观察到的 ACT 值明显降低。
本研究使用 i-STAT 1 为健康犬提供了 ACT 的 RI，并提示个体内日内和日间变异性低。分析仪的可靠性和分析间一致性良好；然而，分析延迟和日间差异可能会显著影响 ACT 结果。
