Sir.—The article by Sindel et al1 provides interesting new data suggesting that asymptomatic infants present with frequent gastroesophageal reflux (GER) in the proximal esophagus, and mechanical ventilation might be associated with a decline in gastroesophageal reflux in infants with bronchopulmonary dysplasia. Our own data about distal esophageal pH recordings strengthen these observations.
We investigated 42 mechanically ventilated premature infants (27 to 36 weeks' gestation), maintained in a supine position and parenterally fed. The duration of recordings ranged from 37 to 120 hours (mean [—SD], 94±28 hours). The mean (±SD) values for the percentage of time with distal esophageal pH less than 4, the number of acid GER episodes per hour, and the number of GER episodes lasting for more than 5 minutes per hour were 3.5% ± 3.3%; 1.2 ±1.4 episodes; and 0.08 ±0.09 episodes, respectively. These results did not exceed values we previously obtained in 46 asymptomatic neonates