2019 #1 Ultrasound guided inferior alveolar nerve block in the horse: assessment of the extraoral approach in cadavers

Question 1

What is the aim of injecting lower volumes of local anaesthetic

Answer 1

to reduce the risk of inadvertent tongue paralysis by decreasing the likelihood of injection diffusion resulting in blockade of the lingual nerve

Question 2

How were injections regarded as successful?

Answer 2

if methylene blue dye staining was present of the inferior alveolar or lingual nerves

Question 3

The ultrasound guided approach resulted in a positive inferior alveolar nerve block in what % of injections on CT?

Answer 3

81.3%

Question 4

How successful was the injection technique?

Answer 4

Methylene blue dye staining was found in 68.8% of all injections on gross dissection. Staining occurred of the IAN with 75% of the 2.5ml injections and 62.5% of the 5mls injections

Question 5

How many specimens had methyl blue staining of the lingual nerve on gross dissection?

Answer 5

11/16 (68%)

Question 6

why would the authors not recommend bilateral IANB using the ultrasound guided extraoral vertical approach

Answer 6

due to increased risk of lingual laceration following bilateral desensitisation

Question 7

What were the conclusions?

Answer 7

Ultrasound guided vertical extraoral approach provided improved visualisation of the anatomical landmarks to facilitate more precise localisation of injection, this approach did not provide any advantages over the blind approach with respect to inadvertent desensitisation or nearby structures, mainly the lingual nerve.