Blood products: Nursing pharmacology

Blood products are natural components of blood that can be transfused as adjuncts or replacement therapy. They can be used in conditions that increase the risk of bleeding, like thrombocytopenia, platelet dysfunction, or clotting factor deficiencies, as well as symptomatic anemia, and for hypovolemic shock that is secondary to trauma or severe bleeding.

Now, there are different types of blood products, depending on what they contain. Whole blood contains red blood cells, white blood cells, platelets, and plasma. On the other hand, some clients may be transfused with specific blood components. This includes packed red blood cells, or PRBCs for short, which are red blood cells that have been almost completely separated from platelets and plasma; as well as platelet transfusions, and fresh frozen plasma. In addition, specific components can be extracted from plasma, such as albumin, as well as cryoprecipitate, a blood product that contains clotting factors.

Now, the blood for these blood products can be taken from clients themselves, or from a different person. In autologous transfusion, the blood is taken from the client before a scheduled procedure, so that their own blood is reinfused later on. A specific type of autologous transfusion is called intraoperative blood salvage, or cell salvage, and it refers to a retrieval of blood that has been suctioned or drained during surgery from the client’s body cavities, joint spaces, or other closed body sites. The blood is reused and reinjected into the client after it’s been washed or filtered. Another possible blood source is allogenic transfusion, in which case the blood is derived from a compatible donor in terms of ABO and Rh(D) blood group.

Now, all blood products are administered through an intravenous transfusion, and work by replacing the blood components that are missing or dysfunctional. Whole blood transfusions replace all blood components, so they’re indicated to restore severe blood loss. Packed red blood cells replace erythrocytes to restore the oxygen-carrying capacity as well as the blood loss, while platelet transfusions help restore the adequate number of functional platelets needed for hemostasis. Cryoprecipitate and fresh frozen plasma are also important for coagulation and hemostasis, since they help restore the clotting factors. Cryoprecipitate is particularly useful in restoring factors VIII and XIII, and von Willebrand factor, as well as factor I, or fibrinogen, while plasma administration also helps increase the intravascular volume.

Now before administering blood products, it’s important to know the blood type of both the donor and the recipient, and check for compatibility. Now, the blood type is based on two classification systems: the ABO system and the Rh system. The ABO system refers to the type of glycoproteins found on a person’s red blood cells; you can have type A; type B; type A and B glycoproteins; or no glycoproteins, which is called type O blood. On the other hand, the Rh(D) group refers to the presence or absence of the Rh(D) antigen; so people are either Rh positive, meaning they have the antigen on their red blood cells, or they are Rh negative, meaning it’s absent.

So, to check for blood compatibility, first the client’s blood is drawn to identify their ABO and Rh(D) blood groups, as well as screen for antibodies against A, B, and Rh(D) antigens. Then, crossmatching is done by combining the red blood cells of a specific donor with the client’s plasma or serum. If agglutination occurs, the test is considered positive and further testing may be needed, whereas no agglutination is considered negative and is usually sufficient to determine ABO and Rh(D) compatibility.

Ok, now type A clients can receive blood type A or O, because they have antibodies against the B antigen; while type B clients can receive blood type B or O, because they have antibodies against the A antigen; this means that type AB clients have no antibodies against either, and can receive any type of blood; while type O clients have antibodies against both, and can only receive type O. On the other hand, clients that are Rh(D) positive can receive both Rh(D) negative or positive blood, since they do not have antibodies against the Rh(D) antigen; on the other hand, Rh(D) negative clients can’t receive Rh(D) positive blood, since they could develop a hemolytic transfusion reaction. Thus, donor’s with an O negative blood type are considered universal donors, while AB positive clients are considered universal recipients.

Although blood products have very important indications, there are many possible side effects, including transfusion reactions, which can be life threatening. One of the most dangerous transfusion reactions is transfusion-associated circulatory overload, referring to a form of pulmonary edema occurring when clients get large product volumes in a short time; as well as transfusion-related acute lung injury, which can lead to fever, chills, and respiratory distress.

Another dangerous reaction is acute hemolytic transfusion reaction, which usually occurs when a blood product is given to an incompatible client, and manifests as fever, chills, flank pain, leakage from the site of injection and decreased hematocrit.

Then there’s also sepsis, which occurs when the transfused product contains a pathogenic microorganism causing fever, chills, and hypotension; and anaphylactic transfusion reactions, which include allergic reactions, like angioedema, wheezing, and/or hypotension. IgA-deficient clients are at a particularly higher risk for this last complication, since they have anti-IgA antibodies.

Blood products can also cause an urticarial transfusion reaction, referring to hives with no allergic findings; febrile non-hemolytic transfusion reactions, manifesting as generalized fever, sometimes with chills, but no other systemic symptoms; and lastly, primary hypotensive reactions which is a sudden drop in blood pressure that is caused by the transfusion and returns to normal or baseline when the transfusion is stopped. It mostly occurs during platelet transfusions.

Other possible side effects of blood products include diseases transmitted from the donor, such as HIV or hepatitis viruses, as well as bacterial contamination. In addition, citrate toxicity or electrolyte imbalances, such as hyperkalemia and hypocalcemia can occur. Citrate toxicity manifests as myocardial depression and coagulopathy. Hyperkalemia can cause weakness, diarrhea and dysrhythmias, and hypocalcemia can lead to muscle cramps, paresthesias, or hyperactive reflexes. Finally, some clients, especially those getting transfusion of multiple units of blood, can develop iron overload.

Okay, now, it’s important to remember that blood products are contraindicated when there’s ABO or Rh(D) group incompatibility. Rh(D) compatibility is mainly important when receiving red blood cells and platelet units, while it does not apply to acellular components, like plasma and cryoprecipitate. Therefore, Rh(D) negative clients should only receive red blood cells and platelet units from other Rh(D) negative donors, while Rh(D) positive clients can receive them from both Rh(D) negative and positive donors.

Additionally, you should not transfuse a blood unit that’s been taken from the storage bank more than four hours earlier, as room temperature can damage the blood components and increase the risk of bacterial proliferation. Moreover, blood product transfusion is contraindicated in clients at risk of fluid overload, such as those with certain cardiovascular or hematologic conditions. Finally, special attention should be given when clients have religious or cultural objections to receiving blood products.