Influence of gestational age on the EDIN score: an observational study.

BACKGROUND AND AIM: Hospitalised neonates, particularly if preterm, may be exposed to prolonged pain. At present the only validated scale to assess prolonged pain in preterms is the EDIN (Echelle Douleur Inconfort Nouveau-Né) scale. Gestational age has been shown to influence the response of infants to acute pain but its potential effect in the setting of prolonged pain has not been investigated. The aim of the present study was to evaluate whether neonatal maturity as expressed by gestational age and/or postnatal age influences their expression of prolonged pain. METHODS: In a 1 year period, 84 neonates (gestational age 25-41 weeks), referred to the authors' neonatal intensive care unit were evaluated using the EDIN scale two to three times a day (1571 scores). The EDIN scores were categorised as indicative (>6) or not indicative (< or =6) of pain. Gestational age and postnatal age were included in a logistic regression analysis along with some painful situations and analgesic treatment to identify the impact on the EDIN scores. RESULTS: Logistic regression analysis showed that the EDIN scores were positively associated with gestational age (odds ratio 1.166; 95% CI 1.123 to 1.211). Postnatal age, sepsis and presence of respiratory support also influenced the EDIN score. CONCLUSIONS: Gestational age influences expression of prolonged pain. Content validity of the EDIN scale could be improved by adding categories for gestational age and attributing higher basal scores to less mature newborns.

Is the ABC pain scale reliable for premature babies?

AIM: We recently developed the ABC scale to assess pain in term newborns. The aim of the present study was to assess the reliability of the scale in preterm babies. MATERIAL AND METHODS: The scale consists of three cry parameters: (a) pitch of the first cry, (b) rhythmicity of the bout of crying and (c) cry constancy. Changes in these parameters were previously found to distinguish medium and high levels of pain as evaluated by spectral analysis of crying. We enrolled 72 babies to perform the steps usually requested to validate a scale, namely the study of the concurrent validity, specificity and sensibility. Moreover, we assessed the interjudge reliability and the clinical utility and ease of the scale. RESULTS: A good correlation (r = 0.68; r(2)= 0.45; p < 0.0001) was found between scores obtained with the ABC scale and the premature infant pain profile (PIPP) scale, demonstrating a good concurrent validity. The scale also showed good sensitivity and specificity (we found statistically significant differences between mean values of scores obtained in babies who underwent pain and babies who underwent non-painful stimulus.) Interobserver reliability was good: Cohen's kappa = 0.7. CONCLUSION: The good correlation between the two scales shows that the ABC scale is also reliable for premature babies.

Short communication: altered synaptic clustering of GABAA receptors in mice lacking dystrophin (mdx mice).

Dystrophin is selectively localized in the postsynaptic density of neurons in cerebral cortex, hippocampus and cerebellum. Here, we show by double-immunofluorescence staining that dystrophin is extensively colocalized with GABAA receptor subunit clusters in these brain regions. To determine the relevance of this observation, we investigated in mdx mice, which provide a model of Duchenne muscular dystrophy, whether the absence of dystrophin affects the synaptic clustering of GABAA receptors. A marked reduction in the number of clusters immunoreactive for the alpha1 and alpha2 subunits was observed in, respectively, cerebellum and hippocampus of mdx mice, but not in striatum, which is normally devoid of dystrophin. Furthermore, these alterations were not accompanied by a change in gephyrin staining, although gephyrin is colocalized with the majority of GABAA receptor clusters in these regions. These results indicate that dystrophin may play an important role in the clustering or stabilization of GABAA receptors in a subset of central inhibitory synapses. These deficits may underlie the cognitive impairment seen in Duchenne patients.