Ultrasound-guided sciatic nerve block injections in barred owl (Strix varia) cadavers

Area of Science:

• Veterinary Anesthesiology
• Avian Medicine
• Applied Anatomy

Background:

• The sciatic nerve is a primary target for regional analgesia in avian species.
• Ultrasound guidance offers precision for nerve blocks.

Purpose of the Study:

• To describe an ultrasound-guided sciatic nerve injection technique in barred owls.
• To evaluate the distribution of injectate using two different volumes.

Main Methods:

• A descriptive, randomized, assessor-blinded, cadaveric study was performed on 12 barred owls.
• Ultrasound was used to visualize the sciatic nerve, followed by in-plane needle advancement and injection of a ropivacaine/dye solution.
• Two injectate volumes (0.4 mL/kg and 0.2 mL/kg) were tested, and nerve staining was assessed by dissection and CT imaging.

Main Results:

• High-volume (0.4 mL/kg) injections achieved 100% nerve staining.
• Low-volume (0.2 mL/kg) injections resulted in 91% successful nerve staining.
• No aberrant injectate spread into the coelomic cavity was observed.

Conclusions:

• Ultrasound-guided sciatic nerve injection is feasible in barred owls.
• The technique successfully stained the sciatic nerve, indicating potential for analgesia.
• Further research is needed to confirm clinical efficacy for pain management.