Comparison of Rapid Centrifugation Technique with Conventional Centrifugation for Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT) Testing
- 18 Downloads
Prothrombin Time (PT) and activated partial thromboplastin time (APTT) are frequently performed coagulation tests in patients with coagulation disorders especially in critical care areas and in monitoring patients on anticoagulation therapy. In coagulation testing, sample processing especially centrifugation is one of the most critical steps that affect turnaround time (TAT). This study was carried out over a period of 1 year. Three hundred paired samples from patients sent for PT and APTT estimation were included. One sample was centrifuged in a regular bench top centrifuge at 1500g for 20 min. The other sample was divided into two polypropylene aliquots and centrifuged in a microcentrifuge at 13000g for 3 min. The plasma obtained from both methods was tested for PT and APTT using the automated method on STA Compact coagulometer (Stago) using commercial thromboplastin STAR-NeoplastineR C1 Plus and phospholipid (cephalin), STAR-C K PRESTR 5 respectively. Data were analyzed using descriptive statistics, Student t test, correlation coefficient and Bland–Altman plots. Mean PT, INR and APTT for both centrifugation methods was comparable with no statistically significant difference (p > 0.05). PT, INR and APTT also showed good correlation (r > 0.98) when compared between the two methods of centrifugation. Bland–Altman comparison between rapid and conventional methods of centrifugation for PT, INR and APTT also showed acceptable agreement. Rapid centrifugation technique for routine coagulation testing can be used safely with a significant reduction in the TAT. This can benefit patients in critical care settings and those on outpatient oral anticoagulant therapy.
KeywordsCentrifugation Conventional Rapid PT APTT TAT
We thank the laboratory technicians of the Clinical hematology laboratory for their assistance during the study.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no competing interests.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. No patient/subject identifying information has been disclosed in the manuscript. No patient/subject intervention was done and the subjects were not exposed to any risks during the study.
Informed consent was taken from the patients included in the study.
- 3.Adcock DM, Hoefner DM, Kottke-Marchant K, Marlar RA, Szamosi DI, Warunek DJ (2008) Clinical and Laboratory Standards Institute: collection, transport and processing of blood specimens for testing plasma-based coagulation assays and molecular hemostasis assay; Approved guideline- H21-A5, 5th edn. NCCLS, WayneGoogle Scholar
- 5.Steindel SJ, Howanitz PJ (2001) Physician satisfaction and emergency department laboratory test turnaround time. Arch Pathol Lab Med 125:863–871Google Scholar
- 8.Boudaoud L, Divaret G, Marie P, Bezeaud A (2006) Rapid centrifugation for routine coagulation testing. Ann Biol Clin 64:315–317Google Scholar
- 9.Kao CH, Shu LC, Yen WH (2010) Evaluation of a high-speed centrifuge with rapid preparation of plasma for coagulation testing to improve turnaround time. J Biomed Lab Sci 22:23–27Google Scholar
- 10.Pappas AA, Palmer SK, Meece D, Fink LM (1991) Rapid preparation of plasma for coagulation testing. Arch Pathol Lab Med 115:816–817Google Scholar
- 11.Nelson S, Pritt A, Marlar RA (1994) Rapid preparation of plasma for ‘Stat’ coagulation testing. Arch Pathol Lab Med 118:175–176Google Scholar