What is transillumination used for in a newborn physical exam?

Transillumination is a valuable diagnostic tool in neonatal assessments, particularly for identifying fluid- or air-filled structures within the body. When a light is passed through a tissue, it helps to reveal abnormalities that may not be visible through conventional examination. For example, transillumination can be utilized to detect conditions such as pneumothorax (air in the pleural space) or effusions (fluid accumulation in body cavities) by examining the ease with which light passes through the affected area.

In a newborn, this technique is especially useful because their tissues are still quite thin and translucent, making it easier to discern between normal and pathological conditions. For instance, when transilluminating the head, excessive fluid (like in hydrocephalus) will allow more light to pass through compared to healthy brain tissue, thereby indicating a potential issue.

While the other options pertain to important aspects of a physical exam, they do not specifically relate to what transillumination is used for. Blood flow assessment typically involves methods such as Doppler ultrasound, heart rate measurement is done through fetal monitors or pulse checks, and evaluating skin integrity is assessed visually and through palpation. These methods provide complementary information; however, they do not utilize transillumination's unique capability