Cardiorespiratory events recorded on home monitors: the effect of prematurity on later serious events.

OBJECTIVE: To describe severe alarms on home-documented monitoring in infants born prematurely.

METHODS: In infants born at a post-menstrual age (PMA) less than 35 weeks, a polysomnography was performed before discharge. A heart rate less than 50 beats per minute (bpm) for more than 3 seconds or an apnea lasting for more than 15 seconds with a heart rate less than 60 bpm were defined as abnormal. These babies were given cardiorespiratory home monitoring with memory. Serious alarms on the home monitor were defined as heart rate less than 50 bpm for more than 3 seconds.

RESULTS: Of 1058 infants, 96 infants needed cardiorespiratory home monitoring. Sixty-one infants showed alarms at home. The mean post-conceptional age (PCA) when alarms stopped was 46 weeks. Seventeen patients had serious alarms above the PCA of 50 weeks. There was a significant negative correlation (r = -0.46 and p = 0.0002 by Spearman's rank correlation) between the PMA at birth and the PCA at which the last alarm was noted

CONCLUSION: Prematurely born infants with an abnormal polysomnography at discharge are at high risk for developing acute events at home. A younger PMA at birth correlates with a higher risk of alarms at a later PCA.