Acute pain management in the neonate

Abstract

Increasing numbers of very young and physiologically immature newborn infants experience pain, particularly those who need surgery or spend time in intensive care. The management of this pain is a challenge because it is difficult to measure, few safe analgesics are available and the nociceptive system of the infant functions differently from that in older patients. Postnatal maturation of the peripheral and central nervous system has important implications for pain and its consequences; changes in nociceptive processing alter the response to painful inputs and to analgesics. Furthermore, it is likely that pain in early life can have long-term consequences on subsequent development and the response to pain experienced later. Analgesia may have a role in preventing or modifying these effects. The analgesics most often used for neonates are paracetamol (acetaminophen), the opioids (particularly morphine and fentanyl) and local anaesthesia. The pharmacodynamic effects of immaturity as well as the pharmacokinetic factors resulting from changes in body composition and maturation of hepatic enzyme metabolism and renal excretion systems, also have an enormous impact on analgesic doses and regimens. Non-pharmacological strategies to prevent or reduce pain may also be effective and should be used alongside conventional analgesia as part of a multi-modal approach to pain management.