Cabral DM, Antonini SRR, Custódio RJ, Martinelli Jr CE, da Silva CAB. Measurement of Salivary Cortisol as a Marker of Stress in Newborns in a Neonatal Intensive Care Unit. Hormone Research in Paediatrics. 2013;79(6):373-8. As I noted previously, we have just published about salivary cortisol concentrations in a study of co-bedding of twins. This study shows that stressed newborns generally have higher (much higher) salivary cortisol than healthy control newborns. I am sure the readers of this blog could point out many potential biases in this study, but nonetheless it is suggestive that this non-invasive test does reflect stress.

Harlos MS, Stenekes S, Lambert D, Hohl C, Chochinov HM. Intranasal Fentanyl in the Palliative Care of Newborns and Infants. Journal of Pain and Symptom Management. 2013;46(2):265-74. If you don’t have an IV, how to manage pain and distress in a dying baby can be problematic. This study notes that intranasal fentanyl was well tolerated, and appeared to be effective.

Cohen AM, Cook N, Harris MC, Ying GS, Binenbaum G. The pain response to mydriatic eyedrops in preterm infants. J Perinatol. 2013;33(6):462-5. No wonder that pain control for retinal exams is difficult, it even hurts when you put the eye-drops in ! Preterm babies have somewhat stereotyped responses to being disturbed. So when we, as adults, get something unpleasant but not actually painful done (such as the prostate exam!) we can say ‘ew’, and when a truly painful event occurs we say ‘ow’. Preterm babies say ‘ow’ for both. They may experience similar sensations and have similar adverse endocrine responses for both, or not; we don’t really know. Putting eye-drops, in we wouldn’t ordinarily suppose to be painful, but preterm babies have increases in pain scores, and about a third have significant increases, when they are prepared for their eye exams. 

Vinall J, Miller SP, Bjornson BH, Fitzpatrick KPV, Poskitt KJ, Brant R, et al. Invasive Procedures in Preterm Children: Brain and Cognitive Development at School Age. Pediatrics. 2014 February 17, 2014. With all respect to this great group of authors, I think it is impossible to separate the results of invasive procedures from the reasons that the procedures were done. The more procedures you had, the sicker you were, and this study shows that even at 7 years of age the lower is the fractional anisotropy of your white matter. These two factors (invasive procedures and FA) were correlated with poorer development. I think it is very likely that the pain associated with many procedures is important, but the reason you needed them is probably also important.