Efficacy of Erector Spinae Plane Block for Back Pain Referred from Visceral Pain in the Palliative Care Setting

Background: Erector spinae plane (ESP) block, an easy and safe interfascial plane block under ultrasound guidance, has an analgesic effect in various surgeries for chronic pain. However, no study has described the possible clinical efficacy of ESP block in palliative patients suffering from back pain referred from visceral pain. Case Report: Here we report three cases of successful ESP block at the middle to lower thoracic vertebras with 5–10 mL local anesthetic to relieve back pain referred from thoracic or abdominal visceral cancer pain. Back pain in these cases was derived from spinal extensor muscles supplied by the dorsal rami of the spinal nerve. Thoracic or abdominal visceral pain was suggested to stimulate the middle to lower thoracic dorsal rami of the spinal nerve. Conclusion: Despite the effect of ESP block on the ventral rami of the spinal nerve being uncertain, back pain accompanied by the lateral and medial branches of the dorsal rami of the spinal nerve, similar to that in these cases, can be relieved via ESP block. Therefore, ESP block can be easily and safely performed for relieving back pain referred from visceral pain in the palliative care setting. Further, to establish optimal volume, concentration of local anesthetic, and clinical efficacy, randomized control trials will be essential in the future. Key words: Erector spinae plane block, fascial plane block, referred pain, palliative care setting, dorsal rami of the spinal nerve, ventral rami of the spinal nerve, visceral pain, chronic pain