Coagulation
Coagulation laboratory tests
Coagulation laboratory tests - overview
Author: Jeremy C. Parsons, M.D.
Last author update: 1 June 2012
Last staff update: 4 March 2022
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Coagulation laboratory tests [title]
Table of Contents
Definition / general | Laboratory | General algorithm | Bleeding tests | Clotting tests | Additional referencesCite this page: Parsons JC. Coagulation laboratory tests - overview. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/coagulationcoaggeneral.html. Accessed April 20th, 2024.
Definition / general
- Performed in almost all hospitals in US
- Necessary for diagnosis, treatment and management of bleeding and hypercoagulation disorders, to screen for coagulation disorders and to monitor anticoagulant therapy
- CAP requires laboratories to notify medical staff immediately if a critical value is obtained
- For critical values, CLIA requires laboratory to immediately alert individual or entity that requested the test, or if applicable, the individual responsible for using the test results
Laboratory
- Tubes with 3.2% citrate are preferred over 3.8% citrate (higher concentration prolongs PT and PTT if tube not filled to the recommended level)
- Do not draw specimens from indwelling catheters (which contain anticoagulants)
- If multiple tubes are drawn, draw coagulation tube after the red top and before the EDTA, heparin or oxalate / fluoride tubes
- Try to fill the sample tube completely
- Notify laboratory if patient is on anticoagulants and specify which ones
- Do not delay transport of tubes to laboratory; if delay cannot be avoided, separate plasma or serum from cells as soon as possible; store plasma (or serum) on ice for up to 4 hours, or store frozen
General algorithm
Bleeding tests
Clotting tests
Additional references
