[Pain assessment in newborn infants--a review of the literature].

While adults and children can express pain verbally it is not possible to appreciate pain immediately in neonates owing to their lack of language. Pain in the newborn must therefore be assessed indirectly and thus involves the use of physiological, behavioural and biochemical parameters. The present review of the literature describes the difficulties accompanying an objective appreciation of pain among the newborn, in particular in the case of premature babies. Most of the existing scales of pain have been developed for the purposes of research and their practical application in a regular clinical context has never been tested. Nurses and doctors are therefore still faced with the problem of having to use a small number of substantiated tools which, however, have hardly been tested in practice. This is all the more questionable since according to the literature the short and long-term consequences of continuous pain in neonates can include intraventricular haemorrhages, changes in feeding and sleeping patterns and damages to the delicate relationship between the infant and its parents.