What should a phlebotomist do to avoid the risk of backflow of an ...

[Melani1276]

What should a phlebotomist do to avoid the risk of backflow of an anticoagulant from a blood vacuum tube into the patient's circulation during blood collection by venipuncture?
 
  What will be an ideal response?

Question 2

Explain how the coagulation of blood can be prevented by the addition of oxalates, citrates, EDTA, or heparin.
 
  What will be an ideal response?

[sylvia]

Answer to Question 1

Answer: The phlebotomist needs to place the patient's arm in a downward position and the tube stopper (top) in the uppermost position to avoid the risk of backflow of an anticoagulant from a blood vacuum tube into the patient's circulation during venipuncture.

Answer to Question 2

Answer: Oxalates, citrates, and EDTA prevent the coagulation of blood by removing calcium and forming insoluble calcium salts. These three anticoagulants cannot be used in calcium determinations; however, citrates are frequently used in coagulation blood studies. EDTA prevents platelet aggregation and is therefore used for platelet counts and platelet function tests. Fresh EDTA-anticoagulated blood allows preparation of blood films with minimal distortion of white blood cells (WBCs). Heparin, a mucopolysaccharide used in assays, such as ammonia and plasma hemoglobin, prevents blood clotting by inactivating the blood-clotting chemicals thrombin and Factor X.