Question

the weight of a 3 - month - old infant with tetralogy of fallot has declined from the 25th percentile to the 5th. which mechanism would the nurse suspect is the reason for this inadequate weight gain?
cyanosis resulting in cerebral changes
decreased arterial oxygen level resulting in polycythemia
pulmonary hypertension resulting in recurrent respiratory infections
inadequate oxygen perfusion leading to activity intolerance, resulting in diminished energy to nurse

Explanation:

Tetralogy of Fallot is a congenital heart defect. In this condition, there is inadequate oxygen perfusion. This leads to activity intolerance. As a result, the infant has diminished energy to nurse. Without proper nursing (feeding), there will be inadequate weight gain. Cyanosis causing cerebral changes (first option) is more related to neurological symptoms rather than weight gain. Decreased arterial oxygen leading to polycythemia (second option) is a compensatory mechanism for low - oxygen levels but not directly the cause of weight loss. Pulmonary hypertension causing recurrent respiratory infections (third option) is not the main mechanism for the described weight decline in this context.

Answer:

Inadequate oxygen perfusion leading to activity intolerance, resulting in diminished energy to nurse.