Keidel A, Mischke R
Klinik für kleine Haustiere der Tierärztlichen Hochschule Hannover.
Berl Munch Tierarztl Wochenschr. 1998 Nov-Dec;111(11-12):452-6.
The platelet-function-analyzer PFA-100 (Fa. Dade Behring, Liederbach) proofs the capillary in vitro bleeding time by the blood flow through a capillary. The membrane at the end of the capillary is a membrane with a layer of an inductor of the platelet aggregation (collagen/ADP or collagen/epinephrine). The closure time and optional the blood volume flowing out of the capillary can be determined. To find out the applicability of the analyzer for canine blood samples several examinations were carried out in this study. Based on 45 blood samples of clinically healthy dogs a reference range (2.5%- and 97.5% quantile) was defined. Using the collagen/ADP test cartridge the reference range for the closure time was 47-81 s and for the blood volume 223-303 microliters. Using the collagen/epinephrine test cartridge the reference range for the closure time was 67-210 s and for the blood volume 269-611 microliters. In addition, blood samples (n = 19) of dogs with different degrees of thrombocytopenia were examined. Hereby, in contrast to the collagen/epinephrine cartridge, the collagen/ADP cartridge showed a high sensitivity regarding the closure time (n = 18) as well as the blood volume (n = 17). Regarding the results of the healthy dogs and dogs with thrombocytopenia a moderate close correlation was calculated between the in vitro bleeding time and the capillary in vivo bleeding time (rs = 0.590). After intravenous injection of 20 mg/kg acetylsalicylic acid the closure time measured with the collagen/ADP cartridge was 1.3 fold prolonged. The reference range was not exceeded in every case. With artificial variation of the haematocrit a clear prolongation of the closure time at haematocrit values < or = 25% was demonstrated. These results indicate that clinical usability of the platelet function analyzer in dogs is restricted despite its sensitivity to disorders of primary haemostasis.
血小板功能分析仪PFA - 100（达德拜耳公司，利德巴赫）通过测量血液流经毛细血管的情况来检测体外毛细血管出血时间。毛细血管末端的膜是带有一层血小板聚集诱导剂（胶原蛋白/二磷酸腺苷或胶原蛋白/肾上腺素）的膜。可以测定封闭时间以及流出毛细血管的血量。为了确定该分析仪对犬类血液样本的适用性，本研究进行了多项检测。基于45份临床健康犬的血液样本，确定了参考范围（第2.5百分位数和第97.5百分位数）。使用胶原蛋白/二磷酸腺苷测试盒时，封闭时间的参考范围为47 - 81秒，血量参考范围为223 - 303微升。使用胶原蛋白/肾上腺素测试盒时，封闭时间的参考范围为67 - 210秒，血量参考范围为269 - 611微升。此外，还检测了不同程度血小板减少症犬的血液样本（n = 19）。在此，与胶原蛋白/肾上腺素测试盒不同，胶原蛋白/二磷酸腺苷测试盒在封闭时间（n = 18）以及血量（n = 17）方面表现出高敏感性。关于健康犬和血小板减少症犬的检测结果，体外出血时间与毛细血管体内出血时间之间计算出中等程度的密切相关性（rs = 0.590）。静脉注射20毫克/千克阿司匹林后，用胶原蛋白/二磷酸腺苷测试盒测得的封闭时间延长了1.3倍。并非每种情况都超出参考范围。通过人为改变血细胞比容，结果表明血细胞比容值≤25%时封闭时间明显延长。这些结果表明，尽管血小板功能分析仪对原发性止血障碍敏感，但其在犬类中的临床实用性仍受到限制。
