Cardiorespiratory Events Following the Second Routine Immunization in Preterm Infants: Risk Assessment and Monitoring Recommendations

Abstract

Due to frequent cardiorespiratory events (CREs) in response to the first routine immunization (rIM), current guidelines recommend readmitting and monitoring extremely preterm infants after the second rIM, though evidence on CREs in response to the second rIM is weak. In a prospective observational study, preterm infants with an increase in CREs after the first rIM were monitored for CREs before and after the second rIM. Seventy-one infants with a median gestational age of 26.4 weeks and a median weight of 820 g at birth were investigated at a median postnatal age of 94 days. All but seven infants showed an increase in CREs after the second rIM. The frequency of hypoxemias (p < 0.0001), apneas (p = 0.0003) and cardiorespiratory events requiring tactile stimulation (CRE-ts) (p = 0.0034) increased significantly. The 25 infants (35%) presenting with CRE-ts were significantly more likely to have been continuously hospitalized since birth (p = 0.001) and to receive analeptic therapy at the first rIM (p = 0.002) or some kind of respiratory support at the first (p = 0.005) and second rIM (p < 0.0001). At a postmenstruational age of 43.5 weeks, CRE-ts ceased. Our data support the recommendation to monitor infants who fulfil the above-mentioned criteria during the second rIM up to a postmenstruational age of 44 weeks.

Safety of Hepatitis B Vaccines (Monovalent or as Part of Combination) in Preterm Infants: A Systematic Review

“…In contrast, in certain patient groups, for example, infants who presented with apnoea following vaccination once [ 26 ] or infants who required in-hospital monitoring because of increased recurrence of cardiorespiratory events during the first immunisation [ 30 ], AEFIs were much more common ( Table 1 and Table 3 ). In both studies reporting on such special cohorts, the recurrence of AEFIs was greater than 90%, and one infant in Clifford et al developed a hypotonic hyporesponsive episode [ 26 ].…”

“…These differences are likely due to cohort selection, duration of observation and variability in definitions and reporting. The importance of cohort selection in particular is demonstrated by studies such as Clifford et al [ 26 ] and Bohnhorst et al [ 30 ], which investigated higher-risk infants and consistently observed high AEFI rates. More definitive evidence in this regard would be useful, for example, to identify populations at higher risk of presenting with AEFIs, thus guiding monitoring requirements.…”