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 ≥6 seconds in duration (A₆/D%), periodic breathing, longest apneic episode, and number of episodes >11 and >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<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<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<0.001). No normal infant had an apneic episode >15 seconds in duration, whereas the group with apnea of infancy had 0.4±1.0 episodes of apnea of >15 seconds (P<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.