Local Block Articles Flashcards
In “Comparison of the efficacy and duration of desensitization of oral structures following injection of a lidocaine-bupivacaine mixture via lateral percutaneous and modified infraorbital approaches in dogs” by Pascoe and Chohan in JAVMA 2021 what was found?
6 hound type dogs. Used 2mL of 50/50 lidocaine/bupivacaine mixture wiht a 22g 4.5cm catheter for infraorbital approach.
- Percent of successful blockade not different
- Time to onset not different but duration sig. longer with infraorbital!
- Not sig. different, but larger portion of dogs had desensitization of hard palate with percutaneous approach vs infraorbital.
- Used electrolocation to guide percutaneous approach
In “The effects of lidocaine or lidocaine-bupivacaine administered into the infraorbital canal in dogs” by Pascoe in JAVMA 2015 what were the main take-aways?
- 6 dogs
- Injected 1mL of 50/50 mixture or 1Ml of lidocaine into canal (2/3 of the way into canal)
- Blocks for M4PM and MM2 were inconsistent (especially MM2)– successful for 3 dogs at pM4 and 1 dog at mm2
- Onset within 10 minutes for both types
- Duration sig. longer with Bupivacaine mixture
In “ Comparison of the efficacy and duration of desensitization of oral structures following injection of various volumes of a lidocaine-bupivacaine mixture via an infraorbital approach in dogs” by Pascoe in JAVMA 2020 what was found?
No significant difference in efficacy or duration between the different volumes (1, 2, 3 mL of the 50/50 mixture).
Did deep infraorbital with catheter inserted fully at 4.5cm to lateral canthus.
Had 1 group where all nerve block was put at lateral canthus and in the rest they retracted the catheter 2cm and administered the second half there.
Hard palate and MM2 generally have less duration and less efficacy than MC and M4PM
In “ A transorbital approach to the maxillary nerve block in dogs: a cadaver study” by Langton in Vet. Anesthesia/Analgesia 2017 what were the main points?
- No sign. diff in dye staining between transorbital or percutaneous - used 1mL of new methylene blue
In “A Cadaver study comparing two approaches for performing maxillary nerve block in dogs” by Viscasillas in Vet. Anesth. analgesia 2013 what were the main take-aways?
- Compared infraorbital approach vs percutaneous approach for maxillary nerve
- 37 cadaver heads, used 0.5mL of new methylene blue and went to the lateral canthus.
Maxillary nerve Staining of >6mm in 65% of nerves with infraorbital vs 21% with percutaneous. Sign higher nerve staining for infraorbital and no diff. between anesthetists
Complete staining of maxillary and pterygopalatine in 56% of infraorbital vs 21% in percutaneous
In “Effects of Buprenorphine Added to Bupivacaine Infraorbital Nerve Blocks on Isoflurane Minimum Alveolar Concentration Using a Model for Acute Dental/Oral Surgical Pain in Dogs” By Snyder in JVD 2016 what are important take-aways?
8 adult beagle dogs. Used MAC as a measure. Either got 0.3mL bupivacaine and 0.1mL saline or 0.3mL bupiviacaine and 0.1mL buprenorphine. Infraorbital block 0.5cm into canal. MAC determination evaluated for maximum of 5 days or until return to baseline. 2 dogs with MAC bupbup demonstrated reduced MAC 96 hours after block. But the time extension was not statistically significant!! Both treatments approx 20% MAC reductions.
Cadaveric Evaluation of Injectate Distribution for Two Maxillary Nerve Block Techniques in Cats
Davis, Hoyer, Rawlinson, Frontiers 2021
Brief Overview
- Evaluated percutaneous vs infraorbital techniques in cadavers
- Compared 0.2 and 0.4mL
- Used new methylene blue dye and Iohexal
- Obtained CTs pre and post injection and dissected eyes out of head and measured dye distribution on maxillary nerve.
- No contrast found in globes
-
No significant difference between volume or method!
- Although one PC did miss entirely
- Every specimen had >6 mm dye staining.
What is the MAC of Iso?
1.28%
Memorize this:
0 3 3 1 1
0 2 2 1 1
