Clinical Study of Transient Tachypnea of the Newborn

ABSTRACT

Transient tachypnea of the newborn(TTN) is a benign self-limited disease characterized by early onset and rapid recovery of tachypnea although it may occasionally have a more prolonged and protracted course. A retrospective clinical study was mad on 29 neonates with TTN admitted to NICU of Pohang St. Mary's Hospital from January 1992 to June 1993. The results were as follows 1) TTN(36.2%) was the most common cause of respiratory distress in the neonate followed by idiopathic respiratory distress syndrome(23.8%), pneumonia(18.8%), meconium aspiration syndrome(6.2%), perinatal asphyxia(6.2%), polycythemia(3.8%), anemia(1.2%), persistent fetal circulation(1.2%), paroxysmal supraventricular tachycardia(1.2%) and tracheoesophageal fistula(1.2%) 2) TTN was more frequent in the male term infants but can occur in premature(41.4%) and low birth weight infants(34.5%). 3) The associated perinatal conditions were oxytocin-induction(8 cases, 27.6%), Cesarean delivery(10 cases, 34.5%) and asphyxia(7 cases, 24.2%) 4) Arterial blood gas analysis showed respiratory acidosis in 3 cases and metabolic acidosis in 3 cases but none of TTN showed hypoxia unresponsive to oxygen 5) Chest X-ray showed hyperaeration in 10 cases(34.5%), increased pulmonary vascularity in 8 cases(27.6%), hyperaeration and increased pulmonary vascularity in 6 cases(20.6%) and cardiomegaly in 12 cases(53%). 6) Tachypnea usually appeared within 6hours and abated by 48-72hours but sustained more than 73hours in 7 cases(24.1%) 7) In majority of cases, maximal respiratory rates were below 100 rates/min and administered oxygen concentrations were 20-40%, and their mean values were 81 rates/min, 37.6% respectively. 8) TTN with more prolonged course(> or=48hours) was associated with low birth weight infants, prematurity and higher respiratory rates(> or=100 breaths a minute)(p<0.05).