Home pneumograms in normal infants.

To obtain age-specific normative data, we performed home cardiorespiratory recordings (pneumograms) in 56 normal infants at 1 month of age. A repeat pneumogram was performed at 3 months in 39 infants. Total sleep time was determined and all sleep intervals were summed and analyzed for five respiratory pattern variables: frequency of all apneic episodes greater than or equal to 6 seconds in duration (A6/D%), periodic breathing, longest apneic episode, and number of episodes greater than 11 and greater than 15 seconds. The normal infants at 1 and at 3 months were compared with 66 patients with apnea of infancy. Median A6/D% was 0.1 in the normal infants at 1 and 3 months, compared with 0.64 in those with apnea of infancy (P less than 0.001). Median periodic breathing was 0.4 and 0.2 episodes per 100 minutes in the normal infants at 1 and 3 months, respectively, compared with 1.25 in infants with apnea of infancy (P less than 0.001). Median longest apneic episode was 8.0 seconds in the normal infants at 1 and 3 months, compared with 11 seconds in those with apnea of infancy (P less than 0.001). No normal infant had an apneic episode greater than 15 seconds in duration, whereas the group with apnea of infancy had 0.4 +/- 1.0 episodes of apnea of greater than 15 seconds (P less than 0.01). Despite these significant group differences, use of these respiratory patterns either alone or in combination permitted only about 80% correct classification of normal infants and those with apnea of infancy.