II. Background
- Evaluates the Extrinsic Clotting Pathway
- Plasma collected in a tube containing citrate, which binds Calcium and prevents initial clotting
- Both Calcium and Tissue Thromboplastin added to plasma
- Tissue Thromboplastin activates the Extrinsic Clotting Pathway which is fast (compared with Intrinsic Clotting Pathway)
III. Precautions
- International Normalized Ratio (INR) and ProTime (PT) were developed only to monitor Warfarin
- All Clotting Factors except Factor 8 and vWF are synthesized in hepatocytes
- In Cirrhosis and hepatic failure, INR is a marker of decreased hepatic synthetic function
- Cirrhosis may be associated with an increased INR/PT, but may also be Hypercoagulable
- Elevated INR in Cirrhosis does not reflect bleeding risk
IV. Labs: Normal
- International Normalized Ratio (INR)
- See Warfarin (includes INR targets per condition)
- See Warfarin Protocol (includes INR initiation protocols and maintenance dosing)
- See Warfarin Protocol for the Perioperative Period (includes bridging, and perioperative INR targets)
- ProTime (replaced by INR)
- Range: 10-12 sec (11-15 sec in some assays)
V. Causes: Increased
- Cirrhosis and other Advanced Liver Disease (e.g. Acute Hepatic Failure)
-
Clotting Factor deficiency
- Factor I Deficiency
- Factor II Deficiency
- Factor V Deficiency
- Factor VII Deficiency
- Factor X Deficiency
- Disseminated Intravascular Coagulation (DIC)
- Vitamin K Deficiency
- Afibrinogenemia
- Dysfibrinogenemia
- Medications
VI. Causes: Decreased
- Vitamin K supplementation
- Thrombophlebitis
- Medications
- Glutethimide
- Estrogens
- Griseofulvin
- Diphenhydramine
Images: Related links to external sites (from Bing)
Related Studies
| Definition (MSHCZE) | Quickův test (protrombinový čas, zkr. PT, QT) – test k vyšetření koagulace krve. Provádí se s dekalcifikovanou plasmou (z krve odebrané do citrátu). Testuje tzv. zevní systém aktivace (systém tkáňového faktoru). K plasmě se přidává tkáňový faktor (tromboplastin, faktor III) a koagulace se spouští kalciem. Měří se doba, za kterou dojde ke koagulaci. K ní dojde v normální krvi cca za 12–15 sekund, výsledek se pak vyjadřuje jako tzv. INR. Q. t. slouží jako základní koagulační test, užívá se k monitorování antikoagulační terapie warfarinem či dikumaroly (antagonisty vitaminu K), k vyšetření funkcí jater (schopnost proteosyntézy). Prodloužen je např. při jaterní cirhóze, déle trvajícím obstrukčním ikteru( malabsorpce vitaminu K), antikoagulační terapii. (cit. Velký lékařský slovník online, 2013 http://lekarske.slovniky.cz/ ) |
| Definition (NCI_CDISC) | A blood clotting measurement that evaluates the extrinsic pathway of coagulation. |
| Definition (NCI) | A measurement of the clotting time of plasma recalcified in the presence of excess tissue thromboplastin; it is a measure of the extrinsic pathway of coagulation. It is used to determine the clotting tendency of blood, in the measure of warfarin dosage, liver damage and vitamin K status. Factors measured are fibrinogen, prothrombin, and factors V, VII, and X. |
| Definition (MSH) | Clotting time of PLASMA recalcified in the presence of excess TISSUE THROMBOPLASTIN. Factors measured are FIBRINOGEN; PROTHROMBIN; FACTOR V; FACTOR VII; and FACTOR X. It is used for monitoring anticoagulant therapy with COUMARINS. |
| Definition (CSP) | clotting time of plasma recalcified in the presence of excess tissue thromboplastin; used for monitoring anticoagulant therapy with coumarins. |
| Concepts | Laboratory Procedure (T059) |
| MSH | D011517 |
| SnomedCT | 90735005, 142979005, 396451008 |
| CPT | 85610, 1014271 |
| English | Prothrombin Time, Prothrombin Times, Time, Prothrombin, Times, Prothrombin, One stage prothrombin time, PROTHROMBIN TIME, Prothrombin time (PT), Prothrombin test, Prothrombin Time Test, PTT - Prothrombin time, prothrombin time (PT) (lab test), prothrombin time (PT), prothrombin time, Pro-thrombin time, prothrombin times, Test;prothrombin time, Prothrombin time assay, prothrombin test, prothrombin time (PT) test, Prothrombin time test, One stage prothrombin time (procedure), PT, Plasma Prothrombin Test, Protime, Quick one stage prothrombin time, Prothrombin time, PT assay, PT - Prothrombin time, Prothrombin time (procedure), prothrombin time test |
| Dutch | protrombinetest, protrombinetijdtest, protrombinetijd, Protrombinetijd |
| French | Test de temps de prothrombine, Test de prothrombine, Temps de prothrombine, TT (Temps de Prothrombine), TP |
| German | Prothrombinzeittest, Prothrombintest, Prothrombinzeit |
| Italian | Analisi della protrombina, Analisi del tempo di protrombina, Tempo di protrombina |
| Portuguese | Exame de tempo de protrombina, Prova de protrombina, Tempo de protrombina, Tempo de Protrombina |
| Spanish | Prueba de tiempo de protrombina, Prueba de protrombina, tiempo de protrombina rápido en un paso, tiempo de PT, tiempo de protrombina (procedimiento), tiempo de protrombina, Tiempo de protrombina, Tiempo de Protrombina |
| Japanese | プロトロンビン試験, プロトロンビン時間試験, ﾌﾟﾛﾄﾛﾝﾋﾞﾝｼﾞｶﾝ, ﾌﾟﾛﾄﾛﾝﾋﾞﾝｼﾞｶﾝｼｹﾝ, ﾌﾟﾛﾄﾛﾝﾋﾞﾝｼｹﾝ, ラッセルクサリヘビ毒時間, トロンボ試験, トロンボテスト, クイックテスト, プロトロンビン時間 |
| Swedish | Protrombintid |
| Finnish | Protrombiiniaika |
| Russian | PROTROMBINOVOE VREMIA, RASSELA ZMEINYI IAD, VREMIA, TROMBOTEST, ПРОТРОМБИНОВОЕ ВРЕМЯ, РАССЕЛА ЗМЕИНЫЙ ЯД, ВРЕМЯ, ТРОМБОТЕСТ |
| Czech | Protrombinový test, Protrombinový čas, protrombinový čas, PT, prothrombinový čas |
| Polish | Czas Quicka, Czas protrombinowy |
| Hungarian | Prothrombin idő vizsgálat, Prothrombin idő, Prothrombin vizsgálat |
| Norwegian | Protrombintid |
Ontology: International Normalized Ratio (C0525032)
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (CHV) | a unit used to report blood coagulation test |
| Definition (NCI) | A system, commonly called the INR, established by the World Health Organization (WHO) and the International Committee on Thrombosis and Hemostasis for reporting the results of blood coagulation (clotting) tests. All results are standardized using the international sensitivity index (ISI) for the particular thromboplastin reagent and instrument combination utilized to perform the test; the ratio of a patient's clotting time to the lab's mean reference value is normalized against the ISI. (from medterms.com and medicine.ucsf.edu) |
| Definition (NCI_CDISC) | A ratio that represents the prothrombin time for a plasma specimen, divided by the result for a control plasma specimen, further standardized for the International Sensitivity Index of the tissue factor (thromboplastin) used in the test. |
| Definition (NCI) | A measure of the extrinsic pathway of coagulation. The International Normalized Ratio of Prothrombin Time (INR) is the ratio of a patient prothrombin time to a normal (control) sample raised to the power of the International Sensitivity Index (ISI) with a range of 0.8 to 1.2 seconds. |
| Definition (MSH) | System established by the World Health Organization and the International Committee on Thrombosis and Hemostasis for monitoring and reporting blood coagulation tests. Under this system, results are standardized using the International Sensitivity Index for the particular test reagent/instrument combination used. |
| Concepts | Laboratory Procedure (T059) |
| MSH | D019934 |
| SnomedCT | 142988001, 165581004 |
| LNC | LP20762-8 |
| English | INR, INR - Internationalized ratio, International Normalized Ratios, Internationalized ratio, Normalized Ratio, International, Normalized Ratios, International, Ratio, International Normalized, Ratios, International Normalized, International Normalized Ratio of Prothrombin Time, international normalized ratio (INR), international normalized ratio (INR) (lab test), BCR, coagulation studies: INR, bcr, international normalising ratio, international normalize ratio, international normalized ratio, international normalised ratio, international normalizing ratio, international normalized ratios, internationalised ratio, International normalised ratio (procedure), Prothrombin Intl. Normalized Ratio, INR - Internationalised ratio, Internationalised ratio, International normalised ratio, International normalized ratio, International normalized ratio (observable entity), International Normalized Ratio |
| Italian | Rapporto internazionale normalizzato, INR, BCR (INR), International Normalized Ratio |
| Dutch | BCR, internationale genormaliseerde ratio, INR, Ratio, internationale genormaliseerde |
| French | BCR, Rapport normalisé international, RIN, INR (International Normalized Ratio), TNI (Taux Normalisé International), INR, Taux normalisé international |
| German | BCR, International normalized ratio, International normalised ratio, INR, International Normalized Ratio |
| Portuguese | Relação internacional normalizada, BCR, International Normalized Ratio, Relação normalizada internacional, INR, Coeficiente Internacional Normatizado |
| Spanish | INR, Razón normalizada internacional, RIN, razón internacional normatizada (entidad observable), razón internacional normatizada, Proporción normalizada internacional, RNI, Relación Normalizada Internacional |
| Japanese | ＢＣＲ, BCR, 国際正規化比, 国際標準化比, ｺｸｻｲﾋｮｳｼﾞｭﾝﾋ, INR, ＩＮＲ, 国際標準比 |
| Swedish | INR |
| Czech | mezinárodní normalizační poměr, INR, Mezinárodně normalizovaný poměr, Mezinárodně normalizovaný poměr (international normalized ratio) INR |
| Finnish | INR |
| Russian | SVERTYVANIIA KROVI TESTOV MEZHDUNARODNAIA SISTEMA, СВЕРТЫВАНИЯ КРОВИ ТЕСТОВ МЕЖДУНАРОДНАЯ СИСТЕМА |
| Polish | Wskaźnik INR, Współczynnik INR, INR |
| Hungarian | INR, International normalised ratio (INR), BCR, Nemzetközi normalizált arány (INR) |
| Norwegian | INR-verdier, INR, Internasjonalt normalisert forholdstall |
Ontology: Point in time (C1442880)
| Concepts | Temporal Concept (T079) |
| LNC | LP6960-1 |
| English | Pt, Point in time |
