In a child with Tetralogy of Fallot, what RBC count is expected?

In a child with Tetralogy of Fallot, a higher red blood cell (RBC) count is often expected due to the body's response to chronic hypoxemia (low oxygen levels in the blood). Tetralogy of Fallot is a congenital heart defect characterized by four specific heart abnormalities, leading to decreased blood flow to the lungs and resultant oxygen deficiency in systemic circulation.

To compensate for the lack of oxygen, the body increases the production of red blood cells in a process known as secondary erythrocytosis. This adaptive mechanism aims to enhance the oxygen-carrying capacity of the blood, resulting in elevated RBC counts. Therefore, a count of approximately 6.8 million/uL reflects this compensatory response to chronic hypoxia seen in children with Tetralogy of Fallot, making it the expected finding.

In contrast, lower RBC counts would not adequately reflect the physiological adaptations to the oxygen deprivation faced by these children. Thus, a significantly elevated count aligns with the conditions and compensatory mechanisms inherent in Tetralogy of Fallot.