Quail M Thomas
Department of Public Health, Bureau of Environmental Health, Commonwealth of Massachusetts, Boston, MA 02108, USA.
J Pediatr Oncol Nurs. 2013 Jul-Aug;30(4):198-204. doi: 10.1177/1043454213487436. Epub 2013 Apr 29.
Nurses often encounter abnormal laboratory assays that require them to investigate further to ensure that appropriate patient care is provided. A prolonged activated partial thromboplastin time (PTT) with a normal prothrombin time (PT) assay demand further examination, to rule out laboratory error or bleeding disorders. Prekallikrein deficiency is a rare coagulation deficiency that presents itself with a prolonged PTT and a normal PT. It was first identified in 4 of the 11 Fletcher family children in 1965, coincidentally when one of the Fletcher children was undergoing a workup for an adenoidectomy. Both the Fletcher parents had normal coagulation laboratory assays with no history of bleeding tendencies. The term Fletcher factor deficiency was used until Fletcher factor was later identified as plasma prekallikrein. A prekallikrein deficiency is inherited as an autosomal recessive trait. The purpose of this article is to provide a basic review for nurses on hemostasis, identify the 6 causes of a prolonged PTT with a normal or slightly prolonged PT, and to present 2 recently diagnosed adult cases, not previously reported in the medical literature.
护士经常会遇到异常的实验室检测结果，这就要求她们进一步调查，以确保为患者提供恰当的护理。活化部分凝血活酶时间（PTT）延长而凝血酶原时间（PT）检测正常，需要进一步检查，以排除实验室误差或出血性疾病。前激肽释放酶缺乏是一种罕见的凝血因子缺乏症，表现为PTT延长而PT正常。1965年，在弗莱彻家族的11个孩子中，首次在4个孩子身上发现了这种疾病，巧合的是，当时其中一个弗莱彻家的孩子正在接受腺样体切除术的检查。弗莱彻夫妇的凝血实验室检测结果均正常，且无出血倾向病史。在弗莱彻因子后来被确定为血浆前激肽释放酶之前，一直使用弗莱彻因子缺乏这一术语。前激肽释放酶缺乏症是一种常染色体隐性遗传性状。本文旨在为护士提供关于止血的基础综述，确定PTT延长而PT正常或略延长的6个原因，并介绍2例最近诊断的成年病例，这在医学文献中此前未见报道。
