Which diagnostic method is considered the gold standard for diagnosing PPHN?

Echocardiography is regarded as the gold standard for diagnosing persistent pulmonary hypertension of the newborn (PPHN) due to its ability to provide detailed information about both cardiac structure and function as well as pulmonary hemodynamics. This non-invasive imaging technique allows clinicians to visualize the heart's anatomy, assess blood flow patterns, and evaluate right ventricular function, all of which are critical in confirming the diagnosis of PPHN.

In patients suspected of having PPHN, echocardiography can reveal significant findings, such as right-to-left shunting through foramen ovale or ductus arteriosus, elevated pulmonary artery pressures, and ventricular hypertrophy, which are essential for establishing the diagnosis and guiding management. Other diagnostic methods like chest X-ray and pulse oximetry provide supportive information but lack the specificity and comprehensive insights offered by echocardiography. A clinical examination, while important, cannot provide the objective data needed to definitively diagnose PPHN, making echocardiography the most reliable and standard method for this condition.