Neonatal Nurse Practitioner Practice Exam

Which is a marker of impaired fatty acid oxidation in neonates?

1. Hyperketonuria

2. Cardiomyopathy

3. Lactic acidosis

4. Hypoglycemia

The correct answer is: Cardiomyopathy

The marker of impaired fatty acid oxidation in neonates is hyperketonuria. This condition occurs when the body is unable to effectively oxidize fatty acids for energy due to a defect in the fatty acid oxidation pathway. In scenarios where fatty acid oxidation is impaired, the body compensates by breaking down fats into ketone bodies, leading to an overproduction of ketones. Hyperketonuria indicates the presence of ketones in the urine and serves as a biochemical marker for the underlying metabolic derangement, highlighting the body's reliance on alternative energy sources when it cannot metabolize fatty acids properly. As such, its presence can signal that the neutered metabolic processes are not functioning optimally. While cardiomyopathy can arise as a consequence of specific inborn errors of metabolism, it is not a direct marker of impaired fatty acid oxidation. Lactic acidosis reflects issues with anaerobic metabolism or hypoxia, and hypoglycemia may be a general finding in various metabolic disorders, but neither of these distinctly indicates fatty acid oxidation impairment in neonates. Hyperketonuria remains the clear and specific marker associated with this metabolic concern.