Clinical Use of the Activated Partial Thromboplastin Time and Prothrombin Time for Screening: A Review of the Literature and Current Guidelines for Testing

https://doi.org/10.1016/j.cll.2014.06.005Get rights and content

Section snippets

Key points

  • Although the activated partial thromboplastin time (aPTT), prothrombin time (PT), and international normalized ratio (INR) are widely used in routine preoperative testing, these hemostatic tests are not reliable predictors of perioperative bleeding in patients without known bleeding risk factors.

  • A preoperative bleeding history and physical examination are usually obtained in an attempt to identify important bleeding risk factors. However, current questionnaires used to assess bleeding history

aPTT

The aPTT is a global coagulation screening test that is used for assessment of the coagulation status in patients with suspected acquired deficiencies of coagulation factors of the intrinsic and common pathways of the coagulation system. The test is affected by multiple factors, including the levels of factors VIII, IX, XI, XII, X, II, and fibrinogen. The aPTT is widely used for monitoring anticoagulation therapy with low levels of heparin (from 0.1 IU/mL to approximately 1 IU/mL). In a normal

PT and INR

The PT measures the time required for clotting to occur after the addition of a source of tissue factor to recalcified citrated plasma in laboratory instruments and on point of care (POC) devices. The PT is measured by adding thromboplastin (a mixture of tissue factor, calcium, and phospholipid) to a patient’s citrated plasma sample, and clot formation is determined. It is used also as a screening assay to detect deficiencies of one or more coagulation factors (fibrinogen and factors II, V,

Utility of aPTT and PT: evidence from the literature

Findings of previously published reviews of the literature on coagulation testing are summarized in Table 2.2, 10, 11, 12, 13, 14, 15, 16, 17, 18 The overwhelming conclusion from these reviews is that routine preoperative hemostatic testing with aPTT and PT is not useful in asymptomatic patients with no known risk factors. Moreover, with aPTT and PT, the high rate of false-positive and false-negative results may lead to inappropriate precautionary measures or false reassurance, respectively.12

Drugs

As would be expected from their indications, anticoagulant therapies (warfarin, heparin, low-molecular-weight heparins) will prolong aPTT and PT test results to a varying extent, depending on the pharmacologic agent. In addition, the antibiotic daptomycin may impact aPTT reagents leading to falsely prolonged results.58

Test Reagents

As described above, test results may vary with the reagent used. Prolonged aPTT times have been reported with micronized silica, celite, and ellagic acid as activators.59 Even

Preoperative Bleeding History and Physical Examination

A preoperative bleeding history and physical examination should be considered to potentially identify any of the bleeding risk factors summarized in Box 113 because many factors may contribute to the bleeding risk. Of paramount importance, a careful medication history should be obtained, including over-the-counter medicines that may contain aspirin and use of any anticoagulation agents or herbal supplements that may affect hemostasis such as platelet function. Particular attention should be

Summary

Coagulation testing using aPTT and PT/INR tests are not reliable predictors of excessive perioperative bleeding risk in patients without other known risk factors. Although routine preoperative use of these tests is common, the data do not support their utility for screening. However, they are used extensively for anticoagulation monitoring with many different anticoagulation agents. A thorough patient and family history, together with physical examination, is vital to identify patients at

First page preview

First page preview
Click to open first page preview

References (89)

  • O. Zagólski

    Post-tonsillectomy haemorrhage–do coagulation tests and coagulopathy history have predictive value?

    Acta Otorrinolaringol Esp

    (2010)
  • R.C. Howells et al.

    Value of preoperative prothrombin time/partial thromboplastin time as a predictor of postoperative hemorrhage in pediatric patients undergoing tonsillectomy

    Otolaryngol Head Neck Surg

    (1997)
  • S.C. Manning et al.

    An assessment of preoperative coagulation screening for tonsillectomy and adenoidectomy

    Int J Pediatr Otorhinolaryngol

    (1987)
  • G.C. Zwack et al.

    The utility of preoperative hemostatic assessment in adenotonsillectomy

    Int J Pediatr Otorhinolaryngol

    (1997)
  • T. Asaf et al.

    The need for routine pre-operative coagulation screening tests (prothrombin time PT/partial thromboplastin time PTT) for healthy children undergoing elective tonsillectomy and/or adenoidectomy

    Int J Pediatr Otorhinolaryngol

    (2001)
  • R. Baker

    Pre-operative hemostatic assessment and management

    Transfus Apher Sci

    (2002)
  • A.H. Kamal et al.

    How to interpret and pursue an abnormal prothrombin time, activated partial thromboplastin time, and bleeding time in adults

    Mayo Clin Proc

    (2007)
  • L.V. Rao et al.

    Stability of prothrombin time and activated partial thromboplastin time tests under different storage conditions

    Clin Chim Acta

    (2000)
  • P.J. Conaglen et al.

    Implications for cardiac surgery in patients with factor XII deficiency

    Ann Thorac Surg

    (2010)
  • U. Seligsohn

    Factor XI deficiency in humans

    J Thromb Haemost

    (2009)
  • J.M. Jackson et al.

    Passovoy factor deficiency in five Western Australian kindreds

    Pathology

    (1981)
  • A.H. Jeske et al.

    Lack of a scientific basis for routine discontinuation of oral anticoagulation therapy before dental treatment

    J Am Dent Assoc

    (2003)
  • J.D. Douketis et al.

    Perioperative management of antithrombotic therapy: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines

    Chest

    (2012)
  • D.A. Garcia et al.

    Parenteral anticoagulants: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines

    Chest

    (2012)
  • J. Puetz

    Fresh frozen plasma: the most commonly prescribed hemostatic agent

    J Thromb Haemost

    (2013)
  • F.R. Rosendaal et al.

    Is administering blood as useless as blood letting?

    J Thromb Haemost

    (2013)
  • W.M. Halbmayer et al.

    The prevalence of moderate and severe FXII (Hageman factor) deficiency among the normal population: evaluation of the incidence of FXII deficiency among 300 healthy blood donors

    Thromb Haemost

    (1994)
  • J. Munro et al.

    Routine preoperative testing: a systematic review of the evidence

    Health Technol Assess

    (1997)
  • Y.L. Chee et al.

    Guidelines on the assessment of bleeding risk prior to surgery or invasive procedures. British Committee for Standards in Haematology

    Br J Haematol

    (2008)
  • S. Shetty et al.

    Comparison of four commercially available activated partial thromboplastin time reagents using a semi-automated coagulometer

    Blood Coagul Fibrinolysis

    (2003)
  • Clinical and Laboratory Standards Institute

    Defining, establishing, and verifying reference intervals in the clinical laboratory; approved guideline

    (2008)
  • World Health Organization (WHO). WHO Expert Committee on Biological Standardization – Thirty-Third report. Annex 3, WHO...
  • D. Sosothikul et al.

    Pediatric reference values for molecular markers in hemostasis

    J Pediatr Hematol Oncol

    (2007)
  • Preoperative routines. The Swedish Council on Technology Assessment in Health Care

    Int J Technol Assess Health Care

    (1991)
  • P. Peterson et al.

    The preoperative bleeding time test lacks clinical benefit: College of American Pathologists' and American Society of Clinical Pathologists' position article

    Arch Surg

    (1998)
  • Y.L. Chee et al.

    Role of coagulation testing in predicting bleeding risk

    Hematol J

    (2003)
  • M.H. Eckman et al.

    Screening for the risk for bleeding or thrombosis

    Ann Intern Med

    (2003)
  • W.H. Dzik

    Predicting hemorrhage using preoperative coagulation screening assays

    Curr Hematol Rep

    (2004)
  • P. Sié et al.

    Central laboratory and point of care assessment of perioperative hemostasis

    Can J Anaesth

    (2006)
  • P. Krishna et al.

    Post-tonsillectomy bleeding: a meta-analysis

    Laryngoscope

    (2001)
  • J.M. Eisenberg et al.

    Prothrombin and partial thromboplastin times as preoperative screening tests

    Arch Surg

    (1982)
  • A.P. Borzotta et al.

    Value of the preoperative history as an indicator of hemostatic disorders

    Ann Surg

    (1984)
  • M.J. Rohrer et al.

    A prospective evaluation of the efficacy of preoperative coagulation testing

    Ann Surg

    (1988)
  • C.R. Macpherson et al.

    Abnormal peri-operative haemorrhage in asymptomatic patients is not predicted by laboratory testing

    S Afr Med J

    (1993)
  • Cited by (0)

    Conflict of Interest Statements: Prof. J.H. Levy serves on steering committees for Boehringer Ingelheim, CSL Behring AG, Grifols, Janssen Pharmaceuticals, and The Medicines Company. F. Szlam, Dr AM Winkler, and Dr A.S. Wolberg have no relevant conflict of interest to disclose.

    View full text