Clinical and Laboratory Standards Institute document H47-A2--One-Stage Prothrombin Time (PT) Test and Activated Partial
Thromboplastin Time (APTT) Test; Approved Guideline--Second Edition describes the principles and procedures necessary for
the routine performance of the PT and APTT by conventional techniques using citrated plasma. Each of the two tests measures
the time for a fibrin clot to develop in test plasma after activation. The chemical reactions are complex and, characteristically,
results are affected by preexamination (preanalytical) and examination (analytical) variables. The PT and APTT are important
screening tests used in laboratory evaluation of patients suspected to have disorders of blood coagulation, including the presence
of circulating coagulation inhibitors. The PT measures the extrinsic or tissue factor pathway of the coagulation system and is used
to monitor oral anticoagulant therapy. The APTT measures the intrinsic coagulation pathway and is used in monitoring heparin
therapy. The objective of this guideline is to improve test reproducibility through standardization of technique and ensure clinical
relevance by setting test performance goals. The document also highlights the international effort for standardization of the PT
through the use of the international normalized ratio (INR).
| Edition : | 2nd |
| File Size : | 1
file
, 400 KB |
| ISBN(s) : | 1562386727 |
| Note : | This product is unavailable in Russia, Belarus |
| Number of Pages : | 48 |
| Published : | 01/01/2008 |
