Which condition is characterized by persistent increased pulmonary pressure and resistance?

Persistent Pulmonary Hypertension of the Newborn (PPHN) is characterized by sustained elevated blood pressure in the pulmonary arteries, leading to increased pulmonary vascular resistance. In PPHN, the normal transition at birth to lower pulmonary vascular resistance fails to occur, resulting in inadequate oxygenation of the blood despite the presence of normal lung function. This condition can severely affect the newborn's oxygenation and breathing efficiency, leading to serious complications.

The condition develops when blood vessels in the lungs do not dilate properly, often due to factors like congenital heart disease, meconium aspiration, or other perinatal issues. Patients with PPHN require careful management, including the use of supplemental oxygen, medications to reduce pulmonary pressure, or mechanical ventilation in severe cases.

Other conditions mentioned, such as pneumothorax, meconium aspiration syndrome, and transient tachypnea of the newborn, do not present with persistent elevated pulmonary pressure as a defining characteristic, which is why they are not the correct answer. Pneumothorax relates to the presence of air in the pleural space, meconium aspiration syndrome involves airway obstruction due to aspiration of meconium, and transient tachypnea of the newborn is typically a self-resolving condition