Case Study: Neonatal Pain
A 1-month-old 4.2-kg male infant is scheduled to have a right thoracotomy and right lower lobectomy for a congenital cystic adenomatoid malformation of the lung.
Is this infant capable of mounting a stress response and experiencing pain after this surgery?
The nociceptive circuitry required to transmit and perceive noxious stimuli is present at birth. Since descending inhibitory pathways are not fully developed for up to 6 months after birth, this infant may experience more pain after thoracotomy than an older child. Severe pain in neonates can result in short- and long-term alterations in behavioral and physiologic responses to pain. Untreated pain may result in a significant physiologic stress response that may adversely affect recovery.
How can you tell whether this infant is having pain?
The best approach is to a look for a variety of behavioral and physiological clues. These include facial expressions, increased crying, altered sleeping and feeding patterns, inability to suck on a pacifier, increased heart rate and blood pressure, mottled skin, and diaphoresis. Pain in an infant can result in breath-holding, irregular and ineffective respirations, and oxyhemoglobin desaturation. Several validated, age-appropriate pain assessment tools are available to determine this infant’s degree of discomfort.
When should you start planning for this patient’s postoperative pain management?
Pain management planning should begin during the preanesthetic evaluation. In the author’s institution the standard analgesic regimen for a neonate undergoing a thoracotomy includes a continuous infusion of epidural local anesthetics. The parents should be told about the risks and benefits of epidural analgesia versus systemic opioid therapy. In this infant, we would use epidural analgesia by advancing a catheter through the caudal canal to the T6 level. An initial intraoperative bolus dose would consist of 3 mL of 0.2% ropivacaine. Postoperatively we would continue epidural analgesia with a continuous infusion of 0.1% ropivacaine at 1 mL/h.