Chief Complaint: Fever
A Complete Blood Count (CBC) in a newborn with fevers is a critical diagnostic tool for several reasons:
1. **Identifying Infection**: Elevated white blood cell (WBC) count, particularly an increase in neutrophils, can indicate a bacterial infection. Conversely, a low WBC count can also be a sign of a serious infection, such as sepsis.
2. **Evaluating Anemia**: The hemoglobin and hematocrit levels can help identify anemia, which may contribute to or complicate the fever.
3. **Platelet Count**: Low platelet counts (thrombocytopenia) can be associated with infections or other serious conditions like sepsis or disseminated intravascular coagulation (DIC).
4. **Differentiating Types of Infections**: The differential count (the breakdown of the types of white blood cells) can help distinguish between bacterial, viral, and other types of infections.
5. **Monitoring Response to Treatment**: Serial CBCs can be used to monitor the newborn’s response to antibiotics or other treatments for infection.
6. **Assessing for Bone Marrow Disorders**: Abnormal CBC results might indicate bone marrow suppression or other hematologic disorders.
In summary, a CBC provides essential information about the newborn's immune response, helps identify potential causes of fever, and guides further diagnostic and therapeutic decisions.