title: Ultrasound-guided proximal paravertebral anaesthesia in cattle.
abstract: 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.
  
  
  METHODS
  prospective experimental cadaveric study and clinical series.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
  
  
  CONCLUSIONS
  Further research should be conducted to improve the ultrasound-guided technique described in this study.
authors.affiliation: Ruminant Clinic, Vetsuisse Faculty, University of Bern, Berne, Switzerland.
authors.forename: Anne H
authors.initials: AH
authors.lastname: Kramer
authors.forename: Marcus G
authors.initials: MG
authors.lastname: Doherr
authors.forename: Michael H
authors.initials: MH
authors.lastname: Stoffel
authors.forename: Adrian
authors.initials: A
authors.lastname: Steiner
authors.forename: Claudia
authors.initials: C
authors.lastname: Spadavecchia
mesh_terms: D000818:Animals; D002102:Cadaver; D002417:Cattle / Q000601:surgery*; D005260:Female; D007278:Injections, Spinal / Q000662:veterinary*; D007813:Laparotomy / Q000662:veterinary; D008159:Lumbar Vertebrae; D009407:Nerve Block / Q000662:veterinary*; D011187:Posture; D011446:Prospective Studies; D013904:Thoracic Vertebrae; D018084:Ultrasonography, Interventional / Q000662:veterinary*
keywords: cattle; proximal paravertebral anaesthesia; ultrasound