本文件描述了使用经认证的等离子体增强凝血酶原时间（PT）/国际标准化比值（INR）系统测试的性能；审查当制造商确定的ISI未经本地验证或校准而使用时，INR系统可能出现的限制；并提供了执行局部ISI验证的基本原理，以及何时指示PT校准的建议。第一部分是对制造商的详细、扩展说明，第二部分是对临床实验室有用的缩写版本。

This document is no longer being reviewed through the Consensus Document Development ProcessThis document describes the use of certified plasmas to enhance performance of the prothrombin time (PT)/International Normalized Ratio (INR) system test; reviews limitations of the INR system that may occur when a manufacturer-determined ISI is used without local verification or calibration; and provides a rationale for performing local ISI verification with recommendations as to when PT calibration may be indicated. Part I is a detailed, expanded account for manufacturers and Part II is an abbreviated version useful for the clinical laboratory.