Successful Management of Chronic Pain and Muscular Contracture by Using Ultrasound-Guided Paraspinal Interfascial Plane Blocks with Bupivacaine and Dexmedetomidine in a Rainbow Boa (Epicrates cenchria) with a Vertebral Fracture

Abstract A 5-yr 6-month-old female rainbow boa ( Epicrates cenchria ) was presented with a mass-like, localized swelling on the right side. Computed tomography (CT) scan revealed a single, comminuted, closed fracture of a vertebra causing minimal vertebral canal stenosis at the point of the localized swelling. To induce local muscle relaxation and provide local analgesia, an ultrasound (US)-guided two-step interfascial plane block was performed bilaterally at the region of interest by using 1 mg/kg bupivicaine. The blocks led to rapid resolution of the muscular contracture, lasting ∼48 h. This technique was repeated 19 days later using 4 mg/kg bupivicaine and 0.02 mg/kg dexmedetomidine. This achieved a rapid resolution of the muscular contracture for ∼33 days. This block was repeated a further three times, resulting in resolution of clinical signs. Subsequent CTs revealed the vertebral fracture was still present, but partial healing was suspected, due to osseous bridging between the fragments and spondylosis, with the vertebral canal moderately distorted at this level. This case presents the successful treatment of paraspinal muscular contracture and pain associated with a vertebral fracture using serial US-guided local blocks with bupivacaine and dexmedetomidine in a rainbow boa. Although evidence of the historic fracture remained, the patients’ clinical signs resolved.