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Apnoea after the 2-month immunisation in extremely preterm infants: what happens with the 4-month immunisation?
Jemma Anderson1, Khurram Noori, Scott A Morris
1Centre for Perinatal Medicine, Flinders Medical Centre, Adelaide, South Australia, Australia.
Insights
Extremely preterm infants experiencing apnea after 2-month immunizations are unlikely to have repeat events at 4 months. Subsequent immunizations appear safe, but further surveillance is recommended.
Area of Science:
- Neonatal Medicine
- Pediatric Immunology
- Clinical Auditing
Background:
- Apnea following infant immunization can be a concern in extremely preterm infants.
- Understanding the recurrence of apnea after subsequent immunizations is crucial for clinical practice.
Purpose of the Study:
- To evaluate the outcomes of 4-month immunizations in extremely preterm infants who experienced significant apnea after their 2-month immunization.
Main Methods:
- A retrospective audit of extremely preterm infants (≤28 weeks + 6 days gestation) at Flinders Medical Centre from 2001-2011.
- Apneic reactions to 2-month immunizations were identified and classified as likely, possible, or unlikely.
- Outcomes of subsequent immunizations were tracked through inpatient monitoring or health unit databases.
Main Results:
- Of 203 extremely preterm infants receiving 2-month immunizations, 17 (8.4%) experienced clinically significant apnea.
- Nine infants with a history of apnea received their 4-month immunization with inpatient cardiorespiratory monitoring, showing no instability.
- No adverse events were reported for the remaining infants who received subsequent immunizations outside of the study hospital.
Conclusions:
- Apnea following the 2-month immunization in extremely preterm infants is unlikely to recur with the subsequent 4-month immunization.
- Prospective surveillance with standardized protocols is needed to guide consistent practices for immunizing this vulnerable population.
Aim:
To describe the outcome of the 4-month immunisation in a cohort of extremely preterm babies who had clinically significant apnoea after their 2-month immunisation.
Method:
A retrospective audit was conducted from January 2001 to January 2011 at Flinders Medical Centre (FMC). Suspected apnoeic reactions to the 2-month immunisation in preterm infants ≤28 weeks + 6 days gestation were identified from the Neonatal Unit database. The medical records of babies with reactions then reviewed. We classified apnoeic reactions using predefined criteria into likely, possible or unlikely. The outcomes for subsequent immunisations were determined either when babies were specifically readmitted to FMC for immunisation and cardiorespiratory monitoring, or from the SA Health Immunisation Unit database.
Results:
There were 203 extremely preterm babies at FMC over the study period who received their 2-month immunisation as inpatients. Clinically significant apnoea post immunisation occurred in 17 (8.4%) babies (likely in 12 and possible 5). The subsequent (4-month) immunisation was given with inpatient cardiorespiratory monitoring in nine babies (seven with likely and two with possible reactions), and no instability was identified. There were eight babies not readmitted to FMC for the subsequent immunisation. No reported adverse events were recorded on the SA Health Immunisation Unit database for these babies.
Conclusions:
Apnoea following the 2-month immunisation in extremely preterm infants is not likely to be repeated with the subsequent immunisation. Prospective surveillance using standardised case definitions and monitoring protocols in this population are required to guide uniform practice.
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