Pediatric ATI Practice Exam 2026 - Free Pediatric Practice Questions and Study Guide

An elevated hemoglobin and hematocrit level in a 2-month-old with cyanotic heart disease indicates a compensatory mechanism in response to tissue hypoxia. Cyanotic heart disease often leads to inadequate oxygen delivery to the body's tissues due to mixed oxygenated and deoxygenated blood. In this context, the body attempts to compensate for the reduced oxygen levels by increasing the production of red blood cells, resulting in higher hemoglobin and hematocrit levels. This adaptive response helps improve the oxygen-carrying capacity of the blood, ultimately promoting better oxygenation of tissues, despite the underlying cardiac condition.

In contrast, dehydration would typically present with elevated hemoglobin and hematocrit levels as well, but it is usually accompanied by other clinical signs such as dry mucous membranes and decreased output. Possible infection might reflect other changes, such as elevated white blood cell counts rather than hemoglobin levels. Fluid overload is characterized by lower hemoglobin and hematocrit levels, as excess fluid dilutes the concentration of red blood cells in circulation. Understanding these physiological responses is crucial for managing and monitoring children with congenital heart defects effectively.