Pneumograms in premature infants: a study of longitudinal data.

In order to define longitudinal data in premature infants, impedance pneumograms were performed weekly on 23 healthy premature infants. Studies were performed while infants remained hospitalized and at the discretion of the attending physician following discharge. A total of 97 studies were obtained on the study group. The recordings were analyzed for percentage of sleep time spent in periodic breathing, apnea density, and duration of longest apneic pause. Infants in this study demonstrated decreased percent of periodic breathing and decreased apnea density with increased maturation; longest pause per recording was independent of postconceptional age. Results from this study provide data to assist in the evaluation of pneumograms in the premature infant.