2 Blood Counts and Coagulation Free Online FlashCards

Which major components does a CBC measure?

A CBC measures red blood cells, hemoglobin, hematocrit, white blood cells, and platelets; it may also report red-cell indices such as MCV.

What can low hemoglobin or hematocrit suggest?

Low hemoglobin or hematocrit may suggest anemia from blood loss, reduced red-cell production, or increased red-cell destruction. Assess symptoms and compare with prior results.

What do low and high MCV indicate?

MCV describes average red-cell size. A low MCV indicates smaller-than-average cells; a high MCV indicates larger-than-average cells. Neither pattern identifies the cause by itself.

Does a high WBC count alone prove infection?

A high WBC count can occur with infection, inflammation, physiologic stress, certain medicines, or other causes. A high count alone does not prove infection.

What does the ANC estimate?

The ANC estimates the number of infection-fighting neutrophils and is more useful for infection-risk assessment than the total WBC count alone.

What ANC is commonly used to define severe neutropenia?

Severe neutropenia is commonly defined as an ANC below 500/µL.

What should happen when a severely neutropenic patient has a fever?

Fever with known or suspected severe neutropenia requires immediate clinical escalation according to local protocol, even if other symptoms seem mild.

What do platelet abnormalities suggest about risk?

Platelets help form the initial plug that limits bleeding. A low count can increase bleeding risk, while a high count may be associated with increased clot risk.

What findings should be checked with thrombocytopenia?

Look for petechiae, unusual bruising, gum or nose bleeding, blood in urine or stool, and persistent bleeding; use bleeding precautions as directed.

Which anticoagulants are commonly monitored with PT/INR and aPTT?

PT/INR is commonly used to monitor warfarin, while aPTT may be used to monitor unfractionated heparin. Interpret results using the prescribed target and laboratory range.

What may an INR below the prescribed warfarin target mean?

An INR below the patient’s prescribed warfarin target may mean anticoagulation is inadequate, increasing clot risk. The target depends on the indication.

How should an unexpectedly prolonged PT/INR or aPTT be interpreted?

Unexpectedly prolonged PT/INR or aPTT means blood may take longer to clot. Assess for bleeding, consider medications and other causes, and report results outside the prescribed target.