Kramer, Anne Hester; Doherr, Marcus; Steiner, Adrian; Stoffel, Michael Hubert; Spadavecchia, Claudia (2014). Ultrasound-guided proximal paravertebral anaesthesia in cattle. Veterinary anaesthesia and analgesia, 41(5), pp. 534-542. Blackwell Science 10.1111/vaa.12148
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Kramer, Doherr et al 2014 - Ultrasound-guided proximal paravertebral anaesthesia.pdf - Published Version Restricted to registered users only Available under License Publisher holds Copyright. Download (425kB) |
OBJECTIVE
To develop and evaluate a method for ultrasound-guidance in performing the proximal paravertebral block for flank anaesthesia in cattle through a cadaveric study, followed by clinical application.
STUDY DESIGN
prospective experimental cadaveric study and clinical series.
ANIMALS
Previously frozen lumbar sections of cows without known spinal abnormalities were used. The clinical case group comprised of ten animals for which a right flank laparotomy was indicated.
METHODS
Twenty cow cadavers were used to perform ultrasound-guided bilateral injections of 1.0 mL dye (1.0 mL 1% Toluidine Blue in 1% Borax) at the intervertebral foramen at the level of T13, L1 and L2 spinal nerves. Distance and depth of injection, staining of the dorsal and ventral nerve branches, and deviation from the target were evaluated. The investigator's confidence as to visualisation and expected success at staining the nerve was assessed. Ten clinical cases received the ultrasound-guided proximal paravertebral anaesthesia. Analgesic success was evaluated using a 4-grade scoring system at 10 minutes after the injection and during surgery, respectively. Categorical variables were described using frequencies and proportions.
RESULTS
Both dorsal and ventral branches of the spinal nerves T13, L1 or L2 were at least partially stained in 41% of injections, while in 77% of injections one of the branches was stained. Five out of ten clinical cases had a satisfactory anaesthesia. There was no significant association between confidence at injection and either staining or analgesic success.
CONCLUSION
Results from the cadaveric and clinical study suggest no significant improvement using ultrasound guidance to perform proximal paravertebral block in cows compared to our previous clinical experience and to references in the literature using the blind method.
CLINICAL RELEVANCE
Further research should be conducted to improve the ultrasound-guided technique described in this study.