Transversus abdominis plane block in rats: Preliminary cadaveric studies

Area of Science:

• Veterinary Anesthesiology
• Surgical Research
• Regional Anesthesia Techniques

Background:

• Transversus abdominis plane (TAP) blocks are ultrasound-guided regional anesthesia techniques for abdominal wall analgesia.
• Previous studies in humans and cats show TAP blocks reduce pain and opioid use post-abdominal surgery.
• TAP blocks have not been previously described in rats, and optimal techniques remain debated.

Purpose of the Study:

• To assess the feasibility of ultrasound-guided TAP blocks in rat cadavers.
• To compare the spread of injectate between single-point and two-point injection techniques for TAP blocks in rats.

Main Methods:

• Ultrasound-guided transversus abdominis plane (TAP) blocks were performed on 23 Sprague Dawley rat cadavers.
• A total volume of 1 ml/kg of methylene blue solution was used for injections.
• Injectate spread was measured for both single-point and two-point injection techniques.

Main Results:

• The overall success rate for performing TAP blocks was low, at 21.7%.
• The area of spread for single-point injections was 87.8 ± 32 mm².
• The two-point injection technique resulted in a larger spread area of 102.4 ± 17 mm².

Conclusions:

• The current technique for ultrasound-guided TAP blocks in rat cadavers is not recommended due to a low success rate.
• The two-point injection technique may provide a greater spread of injectate compared to the single-point technique.
• Further research is needed to draw definitive conclusions and refine the technique for reliable coverage.