Detecting and Evaluating Coagulation Inhibitors and Factor Deficiencies (Online Course)

(based on 324 customer ratings)

Author: Leah Coppolino, MPH, CLS(NCA), MT(ASCP)
Reviewer: Donna D. Castellone, MS, MT(ASCP)SH

What causes a patient's prothrombin time and/or activated partial thromboplastin time to be prolonged when the patient is not on anticoagulant therapy? Is it something that happened as a result of the collection process, is it related to an illness, or is it perhaps related to a factor deficiency or a circulating coagulation inhibitor? This course will acquaint you with several conditions associated with prolonged PT and aPTT test results. You will learn when it is appropriate to perform a mixing study, whether the results suggest a factor deficiency or a coagulation inhibitor, and further testing that can be done to confirm your results.

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Continuing Education Credits

Objectives

  • Determine various causes of an elevated prothrombin time or activated partial thromboplastin time result.
  • Evaluate situations in which performing a mixing study would be appropriate.
  • List the steps involved in a prothrombin time or activated partial thromboplastin time mixing study procedure.
  • Correctly analyze and interpret mixing study results to distinguish a factor deficiency from a circulating inhibitor(s).
  • Determine which, if any, further coagulation studies would prove helpful after obtaining mixing study results.

Customer Ratings

(based on 324 customer ratings)

Course Outline

  • Introduction to Coagulation Inhibitors and Factor Deficiencies
      • Introduction: Coagulation Inhibitors
      • Coagulation Inhibitors
      • Introduction: Factor Deficiencies
      • Coagulation Inhibitors and Coagulation Screening Tests
  • Evaluating prolonged prothrombin time and activated partial thromboplastin time test results
      • Coagulation Factors Monitored By the Prothrombin Time (PT) Test
      • Coagulation Factors Involved in the Activated Partial Thromboplastin Time (aPTT) Test
      • Elevations in PT or aPTT assays
      • Preanalytical Variables That Can Cause Falsely Elevated PT or aPTT Results
      • Summary of Initial Elevations in the PT and aPTT
      • Which of the following may produce a falsely prolonged aPTT test result?
  • Performing a mixing study
      • Introduction to Mixing Studies
      • When To Perform a Mixing Study
      • Mixing studies may help to determine the presence of which of the following?
      • Mixing Study Test Principle
      • Mixing Study: Specimen Requirements
      • Performance of a Mixing Study
      • Performance of a Mixing Study, continued
      • Performance of a Mixing Study, continued
      • What is the ratio of patient plasma to pooled normal plasma that is usually used in the performance of a mixing study?
      • What is the MINIMUM percentage of each coagulation factor that must be present in a patient's plasma to produce a normal PT and aPTT test result?
  • Analyzing and interpreting mixing study results
      • Analyzing the Mixing Study Results
      • Interpreting the Mixing Study Results
      • Initial PT Immediate  Mixing Study PT Incubated Mixing Study ...
      • Analyzing the Mixing Study Results, continued
      • Mixing Study Methodology Differences
      • Analyzing the Mixing Study Results (cont.)
    • Case Study 1
      • Interpreting the Mixing Study Results: Case Study One
      • Case Study One, continued
      • Case Study One, continued
      • Case Study One, continuedWhich factor level(s) could be deficient?
    • Case Study 2
      • Interpreting the Mixing Study Results: Case Study Two
      • Case Study Two, continuedInitial aPTTImmed. aPTT mixing studyIncubated aPTT mixing study86 sec. (normal range 21-34 seconds)87 sec.88 sec.Is the aPTT ...
    • Case Study 3
      • Interpreting the Mixing Study Results: Case Study Three
      • Case Study Three, continuedInitial aPTTImmediate aPTT mixing studyIncubated aPTT mixing study63 sec. (normal range 21-34 seconds)26 sec.65 sec.Has the...
  • Determination of further coagulation studies
      • Further Analyses for Factor Deficiencies
      • Lupus Anticoagulant (LA)
      • Further Analyses for Coagulation Inhibitors
      • Treatment for Factor Deficiencies
      • Further Analyses for Coagulation Inhibitors- Lupus Anticoagulant
      • Further Analyses for Factor Deficiencies (cont.)
      • Further Analyses for Factor Deficiences: Factor Activity Curves
      • Treatment for Coagulation Inhibitors
  • References
      • References

Additional Information

Level of instruction: Intermediate

Intended Audience: Medical laboratory scientists, medical technologists, and technicians, This course is also appropriate for medical laboratory science students and pathology residents.
 
Author information: Leah Coppolino, MPH, CLS(NCA), MT(ASCP) is the Director of the Clinical Laboratory Science Program at St. Christopher’s Hospital for Children in Philadelphia, Pennsylvania. She holds a Masters in Public Health from Thomas Jefferson University.
 
Reviewer information: Donna D. Castellone, MS, MT(ASCP)SH has worked as a coagulation specialist in both clinical and commercial settings. Ms. Castellone holds a Masters Degree in Health Science and Administration from State University at Stony Brook, Stony Brook, New York. She has written over 70 articles, was a contributing author for 3 textbooks, and is a frequent lecturer at laboratory workshops.
Course description: Prolonged PT and aPTT results are caused by many different conditions. It is important for medical technologists to be able to distinguish between preanalytic causes, secondary clinical causes, and important and potentially dangerous causes such as coagulation factor deficiencies and circulating coagulation factor inhibitors. Upon completion of this course, you will be able to identify: the common causes associated with prolonged PT and/or aPTT results, when it is appropriate to perform a mixing study, how to perform and interpret mixing studies, how to differentiate between factor deficiencies and factor inhibitors, and further testing that can be done to confirm mixing study results.




blue top not filled


Properly Filled Sodium Citrate Tube


all 3 tubes incubating at 37 degrees for 90 minutes (or 1 hour, 30 minutes)


1 to 1 mix for incubation step


updated coag cascade 4-2014 LC