Inhalation of low (0.5%–1.5%) CO 2 as a potential treatment for apnea of prematurity

Apnea of prematurity is common and none of the treatments being used are fully effective and free of significant adverse side effects. We hypothesized that low concentrations of CO 2 (≤1.5%) may reduce apnea without causing discomfort from an increase in ventilation. We studied 10 preterm infants at a gestational age of 32±1 wk (mean ± SEM) and birthweight 1.8±0.2 kg. After a control period of 1 hour, concentrations of CO 2 were given (0.5%, 1%, and 1.5%) for 1 hour each, followed by a recovery period of 1 hour. Apnea number significantly decreased from 2.0±0.3 apneas/min during control to 1.0±0.1 apneas/min (0.5% CO2; P