2. Consequences of newborn pain
Newborn pain, which itself is generally a consequence of intervention, has both
immediate, short term and long term consequences. The latter is an emerging
field of research and particularly important as the possible impact of multiple
neonatal pain exposure in the Neonatal Intensive Care Unit (NICU) on
neurodevelopment, potentially contributes to later problems with attention,
learning and behaviour.
Newborn infants subjected to a variety of noxious stimuli have immediate
hormonal, physiological and behavioural responses.7
Term and preterm infants behave differently in their short-term response
to pain. Prior pain experience in healthy, term babies appears to increase
subsequent behavioural response to pain. By contrast, in preterm infants,
prior pain experience may diminish subsequent behavioural response to
pain but not, necessarily, the experience of pain.8
Painful neonatal experiences do have long-term consequences and even
if not expressed as conscious memory,8-10
memories of pain maybe
recorded biologically and alter brain development and subsequent
behaviour.10 This is consistent with laboratory studies in animal models
where early injury can induce long-term behavioural and CNS effects
which persist into adulthood.2
Taddio et al reported that circumcised boys
had higher pain and cry scores during routine immunisation at 4-6
months of age than uncircumcised boys and scores were again higher if
circumcision was unaccompanied by analgesia compared with those
receiving topical anaesthesia.11 Extremely Low Birth Weight (ELBW)
infants demonstrate lower pain sensitivity at 18 months of age compared
with controls and significantly higher scores for non-specific physical
complaints with no known medical cause at 4.5 years of age, as reported
by parents.8
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