Neutropenia
This is a decrease in the Absolute Neutrophil Count (ANC)
The ANC is calculated by by multiplying the total white cell count by the percentage of segmented neutrophils and bands.
This is the biggest factor that increases the risk of infection with bacteria and fungi.
Severity of neutropenia correlates with risk of infection:
- Severe neutropenia = ANC less than 500/mm3
- Moderate neutropenia = ANC 500 - 1000/mm3
- Mild neutropenia = ANC 1000 - 1500/mm3
The risk of infection increases as the ANC decreases.
Neutropenia is usually secondary to chemotherapy but can be due to bone marrow failure from leukemia or aplastic anemia.
Neutropenic patients are usually infected with their own endogenous bacterial flora (so gram negative infections more common)
Fever = Temperature of more than 38 degrees - three times in 24 hours or more than 38.5 degrees once.
Granulocyte Colony Stimulating Factor (GCSF)
- Produces a neutrophil recovery
- Reduces the incidence and severity of infection.
- Well tolerated.
Fever in a neutropenic patient is a medical emergency
see Sepsis and Shock
Bone Marrow failure
Pancytopenia (anemia, low white cell count and thromboytopenia) occurs secondary to chemotherapy and radiation therapy. It can also be due to bone marrow replacement by disease.
Blood component transfusion is often an important part of supportive care in pediatric oncology.
This therapy can be life saving
Risks associated with transfusion are:
- Transfusion Reactions
- Acute hemolytic reaction
- commonest problem
- due to blood group incompatibility
- major and minor red cell antigens
- prevented by typing and Xmatching
- fever, chills, hypotension during transfusion
- Delayed hemolytic reaction
- Febrile transfusion reaction
- due to sensitization to leucocyte antigens
- prevented by leucocyte depleted products
- Allergic reaction
- due to plasma proteins
- Transfusion related acute lung injury
- occurs within 4 to 5 hours of transfusion
- leukoagglutinens in donor blood react with recipient white cells
- white cell complexes are deposited in pulmonary vasculature
- Acute hemolytic reaction
- Development of alloimmunization and refractoriness
- All transfusion recipients become sensitized to foreign leucocyte antigens
- This problem particularly applies to platelet transfusions
- Transmission of infection
- Viruses can be transmitted - HIV, CMV, Hepatitis B and C
- Donated blood is screened for Hepatitis B, C and HIV
- CMV may be transmitted. 85% of the population is positive for CMV.
- Patients who are severely immunocompromised should not be given CMV antibody positive blood.
- Development of Graft Versus Host disease (GVH)
- Can occur 4 to 30 days after administration of non-irradiated blood products to immunocompromised patients.
- Viable stem cells in the donors blood engraft into the recipient's bone marrow.
- This is associated with a high mortality rate and irradiating the blood product prior to administration will prevent this from happening.
Links:
Operation Alysha: Social action group to promote awareness of the need to donate blood
