All of the following are true about transient tachypnea of newborn except-

Transient tachypnea of Newborn o Transient tachypnea of the newborn is a benign self-limiting disease occurring usually in term neonates and is due to delayed clearance of lung fluid. It is also called respiratory distress syndrome type II. TTN follows - Uneventful normal preterm or term vaginal delivery Cesarean delivery TTN is believed to be secondary to slow absorption of fetal lung fluid resulting in decreased pulmonary compliance and tidal volume and increased dead space therefore also known as wet lung Clinical manifestations o Early onset of tachypnea Sometimes retraction or expiratory grunting Occasionally cyanosis Patients usually recover rapidly within 3 days Hypoxemia, hypercapnia and acidosis are uncommon. The lungs are generally clear without rales or rhonchi and chest roentgenogram shows   Prominent pulmonary vascular markings o Fluid lines in the fissure o Prominent inter-labar fissure Overaeration) Flat diaphragm o Occasionally pleural fluid.