Influence of repeated painful procedures on prefrontal cortical pain responses in newborns.
OBJECTIVE
We examined whether previous experience of repeated skin punctures altered the correlation between prefrontal cortical pain responses and Premature Infant Pain Profile (PIPP) scores, compared with infants who had no experience of skin puncture.


METHODS
Eighty infants at 37-42 weeks of gestational age were observed during clinically required blood sampling: full-term infants with no experience of painful skin-breaking procedures before data collection (controls; n = 30), full-term infants with the experience of painful skin-breaking procedures (n = 20) and preterm infants with the experience of painful skin-breaking procedures (n = 30).


RESULTS
We found no significant differences in PIPP scores among groups. In controls, prefrontal activation in both hemispheres correlated with facial expression score of the PIPP (r = 0.53 for right prefrontal area; r = 0.37 for left prefrontal area) and the total score. In full-term infants with the experience of pain, there was no correlation between cortical activation and clinical pain scores. In preterm infants, prefrontal activation in both hemispheres correlated with the physiological component of the PIPP score (r = 0.36 for right prefrontal area; r = 0.41 for left prefrontal area).


CONCLUSIONS
Our findings may be useful in considering the effects of cumulative painful experience on emotion and stress in neonates.
Ozawa
Mio
M
Department of Nursing Administration/Advanced Clinical Nursing, The University of Tokyo, Japan. ozawamio-tky@umin.ac.jp
Kanda
Katsuya
K
Hirata
Michio
M
Kusakawa
Isao
I
Suzuki
Chieko
C
D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D010146:Pain / Q000209:etiology* / Q000503:physiopathology*; D010147:Pain Measurement; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011677:Punctures / Q000009:adverse effects*; D012867:Skin; D019265:Spectroscopy, Near-Infrared