Regional anesthesia for sternotomy and bypass-Beyond the epidural

摘要

Systemic opioids have been the main stay for the management of perioperative pain in children undergoing cardiac surgery with sternotomy. The location, distribution, and duration of pain in these children have not been studied as extensively as in adults. Currently, there is no consensus to the dose of opioids required to provide optimum analgesia and attenuate the stress response while minimizing their unwanted side effects. At present there is a tendency to use lower dose aiming for early extubation and minimize opioid-related side effects, but this may not obtund the stress response in all children. The development of chronic pain although rare when compared to adults is still a risk that needs further investigation. Regional anesthetic techniques, by blocking the afferent impulses, have been shown to be advantageous in reducing the stress response to surgery as well as pain and opioid requirements in children up to 24 hours after cardiac surgery. Central neuraxial blockades have not gained wide spread acceptance in these procedures due to the worry of hematoma, although rare, leading to catastrophic neurological outcomes. This review focuses on blocks outside the vertebral column, ie, peripheral nerve blocks, performed either in the front or the back of the chest wall to target the thoracic intercostal nerves. Techniques of ultrasound-guided bilateral single shot paravertebral block and erector spinae block posteriorly and transversus thoracic plane block anteriorly are discussed. In addition, parasternal block and wound infiltration by surgeon as well as continuous local anesthetic infusion via catheters placed at end of procedures are summarized. Current evidence available for use of these techniques in children undergoing cardiac surgery are reviewed. These are based on small studies and case series and further studies are required to evaluate the risks and benefits of local anesthetic blocks in children undergoing cardiac surgery.