Ce. Hunt et al., HOME DOCUMENTED MONITORING OF CARDIORESPIRATORY PATTERN AND OXYGEN-SATURATION IN HEALTHY INFANTS, Pediatric research, 39(2), 1996, pp. 216-222
The objective of this study was to establish longitudinal normative li
mits for home memory monitors during early infancy. Eighty-eight healt
hy infants were monitored overnight at 0.25-19 wk of age using the Hea
lthdyne Smart Monitor. Apnea settings were 14 s for recording and 40 s
for alarm; the bradycardia setting was 50 beats/min (5-s delay) for b
oth recording and alarm. Arterial oxygen saturation (Sao(2)) was docum
ented whenever an event was recorded. The monitor was used 77% of all
possible days; median daily use was 8.0 h. Eighty-three percent of all
monitor alarms were caused by loose leads, the other 17% by false apn
ea or false bradycardia. Of all recorded events, 68.9% were caused by
false apnea or false bradycardia; the other 31.1% were central apneas
that reached the recording threshold of 14 s. The longest apnea was 36
s (wk 1); the 95th percentile for longest apnea was 19.9 s in wk 1 an
d 18.0 s in wk 17-19 (p < 0.001). Periodic low Sao(2) values occurred
with tiles for lowest Sao(2) were 82 and 86% in wk 1 and 13-19, respec
tively (p < 0.001), but the minimum value observed in any week was nev
er > 81%. The median duration of Sao(2) < 90% was only 5 s but the ran
ge was wide (1-183 s), and 39/527 episodes (7.4%) were > 10 s. In summ
ary, these longitudinal data provide the first available normal limits
for cardiorespiratory pattern and Sao(2) during documented home monit
oring in early infancy. Utilization of these normative data will impro
ve the diagnostic validity and clinical usefulness of event recordings
.