Apnea After Immunization
Predictable in Some Hospitalized Neonates
By David Douglas
NEW YORK (Reuters Health) Mar 12 - Multiple
factors, including severity of illness, predict
apnea following immunization in hospitalized
infants, researchers report in the March issue
"This study," lead investigator Dr. Nicola P.
Klein told Reuters Health, "can help physicians
identify hospitalized premature infants in
neonatal intensive care units who are at risk
for developing apnea after receiving routine
Dr. Klein of Kaiser Permanente, Oakland,
California and colleagues, using data from that
organization, identified more than 16,000
infants who were admitted to the NICU for at
least 53 days. In all, 497 infants received 1 or
more vaccines and met other entry criteria.
All of the 27 infants who had apnea before
immunization, and all but three of the 65
infants who had post-immunization apnea, had
gestational ages of less than 31 weeks.
The most important predictor of apnea after
immunization was having apnea before
immunization, but there were also associations
with a higher 12-hour Score for Neonatal Acute
Physiology II and an age that was less than the
mean for the cohort (67 days).
Forty-nine infants without pre-immunization
apnea and with one or more apnea predictors were
discharged within 48 hours of immunization. Of
these, two were subsequently readmitted because
Overall, concluded Dr. Klein, "focusing on
these at-risk infants could result in improved
vaccine safety because they would likely remain
hospitalized for monitoring after immunization."