RETAINED LUNG FLUID, ALSO KNOWN AS TRANSIENT tachypnea of the newborn, was first described as a syndrome by Mary Ellen Avery in 1966.1Other names that have been applied to this problem are wet lung syndrome and respiratory distress syndrome Type II. It is a diagnosis of exclusion and is generally a benign, self-limiting condition of the term or near-term neonate lasting 24 to 48 hours and occasionally up to 72 hours. The most prominent findings are tachypnea with respiratory rates as high as 120 per minute, grunting, nasal flaring, minimal to no retractions, minimal cyanosis, and mild hypoxemia. The onset of clinical findings appears soon after birth or at birth. Both the clinical and x-ray findings resolve within 72 hours.