Data in the literature report that latency and morphology in the cutaneous sympathetic skin response (SSR) do not change according to the type of stimulus delivered, unlike the amplitude which shows greater values in relation to the intensity of the physical impact caused in patient. Since the acoustic stimulus represents a method better tolerated by the pediatric patient, the aim of this study is to evaluate the presence or absence of significant differences in SSR between electrical and acoustic stimuli. The SSR was performed for each child of 18 recruited in this study, deriving from the palm of the hand and the sole of the foot and initially delivering an electrical stimulus at the level of the median nerve at the wrist. Two acoustic stimuli were subsequently delivered with the aid of audiometric headphones. Our results show no significant differences for the amplitude values obtained (p values > 0.05). For the latency there was a statistically significant difference (p-value = 0.001) for the left hand, subsequently not confirmed by the comparison performed between the two sides (p-values = 0.28 and 0.56). If these preliminary data are confirmed by a larger sample, the acoustic stimulus could be introduced in a standardized protocol for performing SSR in pediatric patients.

Background: Morphine is one of the most common analgesic drug, used to minimizing pain and stress in the hospitalized infants, however, concerns on its role on brain development have been expressed. Aim of the present study was to evaluate the effect of morphine exposure during NICU stay on flash visual evoked potentials (VEP) at term equivalent age (TEA), and on visual outcomes at 9 months corrected age (CA) in preterm infants.Methods: Infants with a gestational age (GA) at birth <30 weeks were prospectively enrolled. Latencies of N1, N2, P2 were measured, as P2 amplitude. N3 was categorized present/absent. Morphine cumulative dose (mg/kg) was calculated as average daily dose adjusted for patient’s weight during the NICU stay. Multivariate regression analyses were performed to assess the association between morphine exposure and VEP components, and visual outcomes. Results: Sixty infants were enrolled. Thirteen infants received morphine (22.8.%). N1, P2 and N2 latency had a positive association with morphine, even after correcting for GA, postmenstrual age at VEP registration, days of ventilation (DOV), retinopathy of prematurity and painful procedures (R=0.42, R=0.47, R=0.43 respectively, and p=0.048, p=0.001, p=0.006 respectively). Presence of N3 component was associated with higher number of DOV (R=0.38, p=0.004). No association was found between morphine and P2 amplitude, and with ophthalmic evaluation.Conclusion: Higher morphine dose predicted longer N1, N2 and P2 latency at TEA. However morphine was not correlated with altered ophthalmic evaluation at 9 months.