Question 1

Aspirin-induced bleeding and Willebrand disease (VWD), type 1, are detected reliably by:&#10;A) Bleeding time&#10;B) Point-of-care testing (POCT)&#10;C) PFA 100 Platelet Function Analyzer&#10;D) Nephelometry

Accepted Answer

PFA 100 Platelet Function Analyzer is the most reliable method for detecting aspirin-induced bleeding and Willebrand disease (VWD), type 1. It is a whole-blood test that measures platelet function and detects the presence of aspirin-like drugs. This test is more sensitive than bleeding time and nephelometry, and it is more specific than point-of-care testing (POCT).

Question 2

Which single instrument development has been the most important improvement in coagulation instrumentation?&#10;A) Multiple-sample dilutions&#10;B) Improved flagging&#10;C) Random access testing&#10;D) Graphing of clot formation

Accepted Answer

Random access testing has significantly improved coagulation instrumentation by allowing for more flexible and efficient testing processes, enabling laboratories to run different tests on different samples in any sequence without the need for batching.

Question 3

Which of the following assays uses indirect measurement using a chromogenic substrate to quantitate heparin?&#10;A) Protein C&#10;B) Thrombin time (TT)&#10;C) Anti-Xa assay&#10;D) Fibrinogen assay

Accepted Answer

The Anti-Xa assay uses indirect measurement with a chromogenic substrate to quantitate heparin levels. The other assays listed do not measure heparin levels. Protein C measures the activity of protein C, which is a natural anticoagulant. Thrombin time measures the time it takes for blood to clot in response to thrombin. Fibrinogen assay measures the amount of fibrinogen in the blood.

Question 4

Examples of instrument malfunction flags include all of the following except:&#10;A) Temperature error&#10;B) Probe not aspirating&#10;C) No end point detected&#10;D) Hemolysis

Accepted Answer

All of the listed choices except for D are examples of instrument malfunction flags. Hemolysis is not an instrument malfunction, but rather a sample quality issue where red blood cells rupture and release hemoglobin into the sample. Therefore, the correct answer is D.

Question 5

Using which principle does plasma become more opaque as a clot forms and the amount of light being detected decreases?&#10;A) Photo-optical&#10;B) Mechanical&#10;C) Chromogenic&#10;D) Immunologic

Accepted Answer

The principle of photo-optical refers to the measurement of light absorption or scattering by a substance. As a clot forms in plasma, it becomes more opaque, meaning that it scatters or absorbs more light, resulting in a decrease in the amount of light that can be detected.

Question 6

Automatic performance of certain tests based on the results of other tests is called:&#10;A) Reflex testing&#10;B) Interpretive liberty&#10;C) Programming flexibility&#10;D) Random access

Accepted Answer

Reflex testing involves automatically performing additional tests based on the results of previous tests. This allows for efficient and thorough testing without the need for manual intervention or decision-making. The other options (interpretive liberty, programming flexibility, random access) do not accurately describe this process.

Question 7

Who should select the coagulation instruments for a given laboratory?&#10;A) Laboratory director&#10;B) Department manager&#10;C) Clinical laboratory scientists&#10;D) All of the previously listed individuals working together

Accepted Answer

All of the previously listed individuals should work together to select the appropriate coagulation instruments for a given laboratory. The laboratory director provides overarching guidance and budgetary considerations, the department manager has knowledge of the specific needs and workflow of the department, and the clinical laboratory scientists have hands-on experience with the instruments and can provide insight into their performance and usability. Working together as a team will ensure the best selection for the laboratory's specific needs.

Question 8

Which of the following is the most common clot detection principle used for coagulation testing?&#10;A) Photo-optical&#10;B) Mechanical&#10;C) Chromogenic&#10;D) Immunologic

Accepted Answer

Photo-optical clot detection is the most common principle used for coagulation testing. It involves measuring the change in light transmission as the clot forms, and is widely used in automated coagulation analyzers. Mechanical clot detection (B) involves measuring changes in pressure or movement as the clot forms, but is less commonly used. Chromogenic (C) and immunologic (D) clot detection principles are used in specific tests, but are not as common as photo-optical detection.

Question 9

Diagnostica Stago coagulation instruments are based on what clot detection principle?&#10;A) Photo-optical&#10;B) Mechanical&#10;C) Chromogenic&#10;D) Nephelometric

Accepted Answer

Diagnostica Stago coagulation instruments use a mechanical end-point clot detection principle.These instruments magnetically monitor the movement of a steel ball within plasma.As the clot forms,the sensor detects the slowing of the ball.

Question 10

Which of the following most improved safety for laboratory scientists?&#10;A) Closed tube sampling&#10;B) Random access&#10;C) Expanded computer capabilities&#10;D) Improved flagging capabilities

Accepted Answer

Closed tube sampling eliminates the need for direct handling of hazardous samples, reducing the risk of exposure to laboratory scientists.

Question 11

All of the following are considered routine coagulation tests that are available in most large and small clinical laboratories except:&#10;A) Prothrombin time (PT)&#10;B) Fibrinogen assay&#10;C) Partial thromboplastin time (PTT)&#10;D) Antithrombin assay

Accepted Answer

The answer of All of the following are considered routine...

Question 12

What is the greatest disadvantage to photo-optical coagulation instruments?&#10;A) High cost&#10;B) Complexity of operation&#10;C) Availability is limited&#10;D) Interference from lipemia, hemolysis, and hyperbilirubinemia

Accepted Answer

The answer of What is the greatest disadvantage to photo-optical...

Question 13

Which of the following principles measures the actual coagulation protein rather than fibrin formation?&#10;A) Photo-optical&#10;B) Mechanical&#10;C) Chromogenic&#10;D) Immunologic

Accepted Answer

The answer of Which of the following principles measures the...

Question 14

Which of the following is true regarding advances in automated coagulation instrumentation?&#10;A) Less staff training is required to operate and maintain the equipment than earlier semiautomatic instruments.&#10;B) Single-sample testing is possible because of increased precision.&#10;C) Newer instruments are less expensive.&#10;D) Accuracy is so improved that controls do not need to be run.

Accepted Answer

The answer of Which of the following is true regarding...

Deck 47: Coagulation Instrumentation