pH 值和储存条件对犬猫离子化钙浓度测量的影响。

Effect of pH and storage conditions on measured ionised calcium concentration in dogs and cats.

机构信息

Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel

Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel.

出版信息

Vet Rec. 2020 Oct 31;187(9):e72. doi: 10.1136/vr.105900. Epub 2020 Jun 22.

DOI:10.1136/vr.105900

PMID:32571985

Abstract

BACKGROUND

Aerobic blood sample collection and processing results in increased serum pH and decreased ionised calcium (iCa) concentration. This prospective study aimed to determine the effect of pH and storage conditions on measured iCa concentration in serum samples obtained from dogs and cats and establish correction formulas for use in samples obtained aerobically.

METHODS

Blood samples were collected from 44 dogs and 25 cats; iCa and pH were measured immediately under anaerobic conditions and in samples stored under several aerobic conditions.

RESULTS

Measured iCa concentrations were significantly lower in samples stored at all aerobic conditions than in samples handled anaerobically in both dogs and cats (P<0.01 for all). The largest and most clinically significant differences were noted in samples stored at -20°C for 30 days in both dogs (0.48 mmol/l; 95 per cent CI 0.40 to 0.55) and cats (0.40 mmol/l; 95 per cent CI 0.33 to 0.47). Correction formulas (corrected iCa=measured iCa+coefficient × (measured pH-7.41); coefficient=0.597 for dogs, 0.627 for cats) yielded good agreement between the corrected and the actual iCa concentrations.

CONCLUSIONS

Samples for iCa measurement can be stored at either 4°C or -20°C for 24 hours. Storage at -80°C is recommended for longer storage time periods.

摘要

背景

有氧条件下采集和处理血样会导致血清 pH 值升高和离子化钙（iCa）浓度降低。本前瞻性研究旨在确定 pH 值和储存条件对犬和猫血清样本中 iCa 浓度测量值的影响，并建立用于有氧采集样本的校正公式。

方法

从 44 只狗和 25 只猫中采集血样；在无氧条件下和在几种有氧储存条件下立即测量 iCa 和 pH 值。

结果

与在无氧条件下处理的样本相比，所有有氧储存条件下的样本中测量的 iCa 浓度均显著降低（所有犬和猫均 P<0.01）。在犬（0.48 mmol/l；95%置信区间 0.40 至 0.55）和猫（0.40 mmol/l；95%置信区间 0.33 至 0.47）中，在 30 天内储存在-20°C 下的样本中观察到最大且最具临床意义的差异。校正公式（校正 iCa=测量 iCa+系数×（测量 pH 值-7.41）；犬的系数为 0.597，猫的系数为 0.627）在校正和实际 iCa 浓度之间产生了良好的一致性。