Which test is used to evaluate the coagulation cascade and is listed among the choices?

Which test is used to evaluate the coagulation cascade and is listed among the choices?

• A. BMP
• B. CBC
• C. PTT
• D. BUN

Answer: (C)

Testing the coagulation cascade is done with clotting times that show how long it takes blood to form a clot in response to specific activators. The partial thromboplastin time, or PTT, targets the intrinsic pathway and the common pathway. By adding an activator and phospholipid to plasma, it measures the time to fibrin clot formation and is sensitive to deficiencies in factors XII, XI, IX, VIII, X, V, II, and I, as well as the effect of anticoagulants like heparin. That’s why it’s used to evaluate coagulation function and to monitor unfractionated heparin therapy. The other listed tests serve different purposes: BMP checks metabolic and electrolyte status, CBC counts blood cells, and BUN evaluates kidney function and nitrogen waste. None directly measure the clotting cascade.

Testing the coagulation cascade is done with clotting times that show how long it takes blood to form a clot in response to specific activators. The partial thromboplastin time, or PTT, targets the intrinsic pathway and the common pathway. By adding an activator and phospholipid to plasma, it measures the time to fibrin clot formation and is sensitive to deficiencies in factors XII, XI, IX, VIII, X, V, II, and I, as well as the effect of anticoagulants like heparin. That’s why it’s used to evaluate coagulation function and to monitor unfractionated heparin therapy. The other listed tests serve different purposes: BMP checks metabolic and electrolyte status, CBC counts blood cells, and BUN evaluates kidney function and nitrogen waste. None directly measure the clotting cascade.