Diagnostic Procedures of the Blood System

Flashcards reviewing diagnostic blood tests, metabolic panels, blood gas analysis, coagulation tests, and newborn screenings based on the lecture.

What is venapuncture?

The puncturing of a vein for the purpose of drawing blood.

Why are blood specimens often placed in a centrifuge?

To separate the cellular and liquid portions of the blood for tests requiring a sample of serum or plasma.

What components are evaluated in a complete blood count (CBC)?

Erythrocytes, leukocytes, hemoglobin, platelets, mean corpuscular volume, and hematocrit.

What does mean corpuscular volume measure?

The average size of the red blood cells.

What is a comprehensive metabolic panel (CMP), also known as a CHEM fourteen?

A broad screening tool that provides information about the state of the body's metabolism by measuring 14 different substances in the blood.

What substances are standardly measured in a basic metabolic panel (BMP) or profile eight?

Four electrolytes (sodium, potassium, chloride, bicarbonate), blood urea nitrogen, creatinine, glucose, and sometimes calciase as an eighth substance.

What does a blood urea nitrogen (BUN) test measure?

The amount of urea nitrogen in the blood.

What is a direct antiglobulin test (DAT) or direct Coombs test used for?

To investigate possible hemolytic transfusion reactions or whether a fetus or newborn has a hemolytic disease.

What does a blood differential test measure?

The percentage of each type of leukocyte present in the blood.

Which cardiac enzyme is released by the heart when injured, indicating a possible heart attack?

Troponin.

What measurements are provided by a blood gas analysis or arterial blood gas test (ABG)?

The amount of oxygen and carbon dioxide in the blood, as well as the pH levels (acidity) of the blood.

What is the Erythrocyte Sedimentation Rate (SED rate) test based on?

The speed with which red blood cells separate from plasma and fall to the bottom of a specialized test tube.

What does an elevated SED rate indicate?

The presence of inflammation in the body.

What is a fibrinogen activity test used for?

To determine the level of fibrinogen in the blood, which may help find the cause of abnormal bleeding.

How is a glucose tolerance test administered and monitored?

Two hours after drinking a syrupy glucose solution, a blood glucose test is conducted to see if the body processed the glucose normally.

What is hematocrit (HCT)?

The percentage of blood that is made up of red blood cells.

What do the word roots 'hemato' and 'crit' mean?

'Hemato' means blood and 'crit' means to separate.

What instructions must a patient follow before drawing blood for a lipoprotein panel?

The patient must fast for eight to twelve hours before the blood is drawn.

When is newborn screening usually performed and how is blood drawn?

It is usually done twenty four to forty eight hours after birth via a prick to the heel.

What conditions or factors can cause a longer prothrombin time (PT)?

Serious liver disease, bleeding disorders, blood thinning medicines, or a lack of vitamin K.

How is prothrombin time expressed for patients taking the anticoagulant medication warfarin?

As an international normalized ratio (INR).

What does a total protein test measure?

The proteins albumin and globulin in the blood, as well as the ratio between the two (referred to as the AG ratio).