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Thromb Haemost 2000; 84(04): 664-667
DOI: 10.1055/s-0037-1614084
Review Article
Schattauer GmbH

A Comparison of Two Sodium Citrate Concentrations in Two Evacuated Blood Collection Systems for Prothrombin Time and ISI Determination

A. M. H. P. van den Besselaar
1   From the Haemostasis and Thrombosis Research Center, Leiden University Medical Center, Leiden, The Netherlands
,
V. Chantarangkul
2   Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Internal Medicine, University and IRCCS Maggiore Hospital, Milano, Italy
,
A. Tripodi
2   Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Internal Medicine, University and IRCCS Maggiore Hospital, Milano, Italy
› Author AffiliationsWe thank Becton Dickinson Vacutainer Systems and Terumo Europe N.V. for providing the blood collection systems. Thromboplastin reagents were given by Dade Behring, Ortho Diagnostics, bioMérieux, and Helena Laboratories. The international reference preparation rTF/95 was provided by the W.H.O. Excellent technical assistance was given by E. Witteveen, H. Schaefervan Mansfeld, J. Meeuwisse-Braun, J. van der Poel-van Veen, and M. Clerici.
Further Information

Publication History

Received 02 February 2000

Accepted after revision 16 May 2000

Publication Date:
11 December 2017 (online)

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Summary

The prothrombin time is usually measured in citrated plasma. The W.H.O. recommended concentration of sodium citrate for blood collection for laboratory control of oral anticoagulant therapy is 0.109 M. Some evacuated blood collection systems include 0.105 M sodium citrate. The purpose of the present study was to establish the difference in ISI calibration between 0.109 and 0.105 M citrate, using 7 types of thromboplastin and various types of instrumentation. The two citrate concentrations were provided in both evacuated siliconised glass tubes and in evacuated polyethylene terephtalate (PET) tubes. The ISI difference between the two citrate concentrations was 5.4% for one system but not greater than 3% for all other systems when blood samples were collected with either siliconized glass or PET tubes. Most of the ISI differences between the two citrate concentrations were not significant at the 5% level. It is concluded that the ISI differences between 0.105 M and 0.109 M citrate are not of practical importance. In contrast, ISI differences between siliconised glass and PET tubes, using either 0.105 or 0.109 M citrate, were significant (p <0.05) for most thromboplastin systems and amounted to 7%. ISI interchange between these glass and PET tubes could induce INR differences amounting to 14%, which could affect clinical dosage of oral anticoagulants.

Key words

Prothrombin time - ISI - oral anticoagulant control - blood collection - citrate
 

  • References

  • 1 Duncan EM, Casey CR, Duncan BM, Lloyd JV. Effect of concentration of trisodium citrate anticoagulant on calculation of the international normalised ratio and the international sensitivity index of thromboplastin. Thromb Haemost 1994; 72: 84-8.
    PubMedSearch in Google Scholar
  • 2 Chantarangkul V, Tripodi A, Clerici M, Negri B, Mannucci PM. Assessment of the influence of citrate concentration on the international normalized ratio (INR) determined with twelve reagent-instrument combinations. Thromb Haemost 1998; 80: 258-62.
    Thieme ConnectPubMedSearch in Google Scholar
  • 3 Ingram GIC, Hills M. Reference method for the one-stage prothrombin time test on human blood. Thromb Haemost 1976; 36: 237-8.
    Thieme ConnectPubMedSearch in Google Scholar
  • 4 W.H.O. Expert Committee on Biological Standardization. Guidelines for thromboplastins and plasma used to control oral anticoagulant therapy. WHO techn rep series. no. 889, 1999
    PubMedSearch in Google Scholar
  • 5 Tripodi A, Chantarangkul V, Negri B, Clerici M, Mannucci PM. International collaborative study for the calibration of a proposed reference preparation for thromboplastin, human recombinant, plain. Thromb Haemost 1998; 79: 439-43.
    Thieme ConnectPubMedSearch in Google Scholar
  • 6 Poggio M, van den Besselaar AMHP, van der Velde EA, Bertina RM. The effect of some instruments for prothrombin time testing on the international sensitivity index (ISI) of two rabbit tissue thromboplastin reagents. Thromb Haemost 1989; 62: 868-74.
    Thieme ConnectPubMedSearch in Google Scholar
  • 7 Van den Besselaar AMHP, Houbouyan LL, Aillaud MF, Denson KWE, Johnston M, Kitchen S, Lindahl TL, Marren M, Martinuzzo ME, Droulle C, Tripodi A, Vergnes C. Influence of three types of automated coagulometers on the international sensitivity index (ISI) of rabbit, human, and recombinant human tissue factor preparations. Thromb Haemost 1999; 81: 66-70.
    Thieme ConnectPubMedSearch in Google Scholar
  • 8 Poller L, Keown M, Shepherd SA, Shiach CR, Tabeart S. The effects of freeze drying and freeze drying additives on the prothrombin time and the international sensitivity index. J Clin Pathol 1999; 52: 744-8.
    CrossrefPubMedSearch in Google Scholar
  • 9 Van den Besselaar AMHP, van Halem-Visser LP, Loeliger EA. The use of evacuated tubes for blood collection in oral anticoagulant control. Thromb Haemost 1983; 50: 676-7.
    Thieme ConnectPubMedSearch in Google Scholar
  • 10 Adcock DM, Kressin DC, Marlar RA. The effect of time and temperature variables on routine coagulation tests. Blood Coag Fibrinol 1998; 09: 463-70.
    CrossrefPubMedSearch in Google Scholar
  • 11 Neofotistos D, Oropeza M, Ts’ao C-H. Stability of plasma for add-on PT and APTT tests. Am J Clin Pathol 1998; 109: 758-63.
    CrossrefPubMedSearch in Google Scholar
  • 12 D’Angelo G, Villa C. Measurement of prothrombin time in patients on oral anticoagulant therapy: effect of two different evacuated tubes. Haematologica 1999; 84: 656-7.
    PubMedSearch in Google Scholar
  • 13 Van den Besselaar AMHP, Meeuwisse-Braun J, Witteveen E, van Meegen E. Effect of evacuated blood collection tubes on thromboplastin calibration. Thromb Haemost 1998; 79: 1062-3.
    Thieme ConnectPubMedSearch in Google Scholar
  • 14 Van den Besselaar AMHP, Bertina RM, van der Meer FJM, den Hartigh J. Different sensitivities of various thromboplastins to two blood collection systems for monitoring oral anticoagulant therapy. Thromb Haemost 1999; 82: 153-4.
    Thieme ConnectPubMedSearch in Google Scholar
  • 15 Heyns duPA, van den Berg DJ, Kleynhans PHT, du Toit PW. Unsuitability of evacuated tubes for monitoring heparin therapy by activated partial thromboplastin time. J Clin Pathol 1981; 34: 63-8.
    CrossrefPubMedSearch in Google Scholar