Management of Pain in the Neonatal Unit: Options, Challenges and Controversies
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REVIEW ARTICLE © 2011 SNL All rights reserved Management of pain in the neonatal unit: options, challenges and controversies Awareness of the importance of pain in newborn babies has increased during recent years, but it remains a challenging area of clinical practice. This article reviews current knowledge, addresses some of the challenges and controversies surrounding neonatal pain and suggests an approach to pain management in the neonatal intensive care unit. Elaine M Boyle ain is unavoidable in modern neonatal their pain. The experience of pain is MBChB, MD, MSc Pintensive care. Advances in obstetric subjective and in adults and older children, Department of Health Sciences, and early neonatal care have led to the we rely on self-report to allow us to University of Leicester survival of increasing numbers of sick and identify and quantify pain and to monitor [email protected] preterm infants of gestational age as low as the effectiveness of pain-relieving 23 weeks. For these tiny patients, life- interventions. Since this is impossible in saving therapy means that a wide range of babies, we will never know precisely how stresses associated with diagnostic, the newborn baby perceives painful therapeutic and nursing interventions are conditions or invasive interventions. all part of day-to-day life. There is no However, it is reasonable to suppose that doubt that our knowledge and expertise in experiences reported as painful or managing these babies has grown, but how distressing by articulate adults, would be have we progressed in the management of similarly perceived by a preverbal infant. pain that they experience on a daily basis? We have turned therefore to interpretation It is only a few years since it was of infant behaviour to assist us in detecting common practice to give no analgesia to their pain. However, the behavioural newborn babies, as they were thought to be repertoire of the neonate is very limited developmentally too immature to process and there is no single response or information about painful stimuli. We have behaviour that we can attribute, with come a long way since then and today it is certainty, to the presence of pain. The widely, if not universally, accepted that situation becomes even more complex if even very preterm neonates are sufficiently we attempt to distinguish between developed, anatomically and different types of pain and quantify the Keywords physiologically, both to perceive and to severity. Finally, we still have much to respond to pain1. However, results of a newborn; premature; pain; analgesia; learn about infants’ responses to pain and recent Canadian survey comparing practice sedation; pain assessment about the risks and benefits of different today with that of 12 years ago suggested methods of pain relief and how they are Key points that, although attention to pain has affected by gestation, postnatal age and Boyle E.M. Management of pain in the improved, the management of procedural severity of illness. neonatal unit: options, challenges and pain in most centres, continues to fall short 2 controversies. Infant 2011; 7(3): 88-91. of current recommendations . In all The effects of neonatal pain 1. Pain management is a crucial part of branches of medicine and nursing we From a purely humanitarian perspective, neonatal intensive care. strive to keep patients comfortable and treating pain in newborn babies is a 2. Assessment of chronic pain in babies is pain free, and so perhaps we should ask desirable aspiration, but appropriate pain particularly challenging. ourselves why it is so difficult for us to get management is important for a number of 3. A range of pharmacological and non- this right in the smallest and most reasons other than the avoidance of pharmocological pain-relieving vulnerable of our patients. distress and suffering. Many researchers measures is available for use in babies. have now described long-term adverse 4. The aim of pain management should be Why are babies so challenging? effects following prolonged or repeated to achieve maximum comfort for Pain management in the newborn is exposure to pain in the neonatal period. babies, while minimising adverse complicated for a number of reasons, not Studies in both animals and humans have effects of treatment. least of which is their inability to describe shown altered behavioural responses to 88 VOLUME 7 ISSUE 3 2011 infant REVIEW ARTICLE pain and these may persist through the COMFORTneo17 are the only ones in milk, holding, comforting and suckling. childhood and perhaps longer3-8. existence and none is widely used. One randomised placebo-controlled trial Interestingly, there appears to be a There are, however, inherent difficulties found that breast milk significantly difference between term and preterm in using pain scores. Physiological decreased pain responses and crying time infants in their later responses following indicators such as increase in heart rate or associated with venepuncture in term painful experiences in the neonatal period. blood pressure lack specificity for pain and neonates22. Animal studies have suggested Studies have shown that term-born infants may often occur as a result of other that analgesic effects of milk may be opioid who had circumcision without analgesia, conditions; different methods of securing mediated and related to the sugar content23. and infants exposed to multiple heel pricks endotracheal tubes may distort or obscure For mothers who feel able to be present for measurement of blood sugar levels had facial features, limiting their use in when their baby is having a painful exaggerated behavioural responses to later ventilated babies. In addition, it is difficult procedure these may be appropriate, immunisation7-8. In contrast, preterm to differentiate between pain and agitation simple and safe options for pain relief. infants who experienced neonatal intensive and the effects of analgesia versus However, parents are not always present to care were reported by their parents to be sedation, especially in critically ill infants comfort or feed babies during invasive less sensitive to pain than their peers6. in whom severity of illness may further interventions and, understandably, many These effects are likely to be as a result of complicate assessment. prefer to avoid watching painful stressful procedures occurring during a Research to identify novel methods of procedures. Other behavioural measures critical period of anatomical and detecting and quantifying chronic pain in that can be administered by staff caring for physiological development of the brain neonates is ongoing. Investigators continue babies have therefore been studied. and nervous system9. to build on the knowledge of behavioural The simplest interventions that have responses14,18. It is likely that, in coming been shown to promote physiological Assessment of pain years, the use of non-invasive techniques, stability during painful procedures are Most research in neonatal pain assessment such as near infrared spectroscopy, may handling techniques such as containment, has centred mainly on acute pain. There provide greater insight into more specific swaddling and facilitated tucking24. Non- are now more than 40 clinical tools pain indicators19. nutritive sucking on a dummy/pacifier, available to allow assessment of the either alone or in combination with presence and severity of pain associated Management of pain sucrose, has also been the subject of with invasive procedures10. Most use a Of course, prevention is better than cure research and has been shown to reduce scoring system; some are used clinically at and it is clear that we must avoid non- pain responses25. Concerns have been the cot side while others are more essential painful procedures. Limiting raised about the possibility of non- frequently used in research studies. invasive interventions to the absolute nutritive sucking adversely affecting the Behavioral indicators and in particular, minimum required for the safe medical establishment of breastfeeding in preterm facial expressions, appear to be the most management of the baby is central to good babies. A recent study found no evidence specific indicators of pain and have been clinical practice. Nevertheless, there are to support withholding dummies/pacifiers included in most tools11,12. Some have frequent occasions when invasive on these grounds26. combined these with physiological procedures are clinically indicated even indicators such as heart rate and oxygen though they may be potentially distressing Pharmacological measures saturation to develop multidimensional for the infant. The choice of procedure or Sucrose scores13. methods used may be important. For Sucrose has been extensively studied27. For In contrast, there are relatively few example, venepuncture appears to be less many years sweet solutions have been validated tools designed for measurement painful than heel prick and heel prick known to have a calming effect in crying of the ongoing or ‘chronic’ pain that might using a spring-loaded mechanical device is babies. The mechanism of action of be experienced during prolonged less painful than using a manual lancet20. sucrose has not been fully defined, but it mechanical ventilation or inflammatory A number of non-pharmacological may be mediated by the activation of conditions such as necrotising entero- measures have been studied, as well endogenous opioids; sweet taste appears to colitis. It may be that responses to this sort as drug therapies, and all may be useful be important.