Periodic breathing in preterm infants: incidence and characteristics.

The prevalence and characteristics of periodic breathing in preterm infants were measured by 24-hour impedance pneumograms in 66 preterm infants before discharge from the nursery. Four periodic breathing parameters (percentage of periodic breathing per quiet time, number of episodes of periodic breathing per 100 minutes of quiet time, mean duration of periodic breathing, and longest episode of periodic breathing) were compared to data available from healthy term infants and from term infants who subsequently died of sudden infant death syndrome (SIDS). Periodic breathing was found in all preterm infants studied and mean periodic breathing parameter values (12.0%, 8.6 episodes, 1.2 minutes, and 7.3 minutes, respectively) in our preterm population were substantially higher than values from healthy term infants and SIDS victims. Most periodic breathing parameters decreased significantly in infants studied at 39 to 41 weeks' postconceptional age compared with earlier postconceptional age groups. No relationship was found between central apneas of greater than or equal to 15 seconds' duration and postconceptional age or any periodic breathing parameter. Periodic breathing is a common respiratory pattern in preterm infants that is usually not of pathologic significance. Associations between elevated levels of periodic breathing and respiratory dysfunction or SIDS should be made with caution.