title: Comparison of lidocaine, levobupivacaine or ropivacaine for distal paravertebral thoracolumbar anesthesia in ewes.
abstract: OBJECTIVE
  To compare the effects of lidocaine, levobupivacaine, or ropivacaine on the onset time and duration of anesthesia of the flank of ewes, using the distal paravertebral thoracolumbar approach.
  
  
  METHODS
  Randomized experimental study.
  
  
  METHODS
  Twenty-six healthy mixed-breed ewes (46 ± 3.1 kg).
  
  
  METHODS
  Thoracolumbar paravertebral nerve blocks were performed using the distal approach in sheep for ruminal fistulation. The 13th thoracic (T13), first lumbar (L1) and second lumbar (L2) nerves were infiltrated with 2% lidocaine (group GLI, n = 9), 0.5% levobupivacaine (group GLE, n = 8) or 0.5% ropivacaine (group GRO, n = 9); 1.5 mL on the dorsal branch and 2.5 mL on the ventral branch, total volume of 12 mL per ewe. Anesthesia onset time and duration were assessed by application of superficial and deep pin pricks, and skin clamping with a hemostat. Heart rate, respiratory rate, rectal temperature and systemic arterial pressures were recorded prior to nerve block (T0), after the anesthetic agent injection and onset time (T1) and predetermined time points during the surgical procedure (T2-T6).
  
  
  RESULTS
  Incomplete nerve blocks were present in five of the 26 ewes enrolled in the study and they were not included in the statistical analyzes. Onset times in GLI, GLE and GRO were 1.5 ± 0.5, 3.1 ± 1.5 and 2.1 ± 0.8 minutes, respectively, with GLE significantly longer than GLI. The durations of anesthesia for GLI, GLE and GRO were 80 ± 27, 649 ± 68 and 590 ± 40 minutes, respectively, with the duration of GLI significantly shorter than GLE and GRO. There were no clinically important changes in cardiopulmonary variables.
  
  
  CONCLUSIONS
  Administration of levobupivacaine and ropivacaine at the distal paravertebral site to block nerves T13, L1 and L2 produced a longer duration of anesthesia of the ewe's flanks compared with lidocaine.
authors.affiliation: Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil.
authors.forename: Alice R
authors.initials: AR
authors.lastname: Oliveira
authors.affiliation: Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil.
authors.forename: Marcelo A
authors.initials: MA
authors.lastname: Araújo
authors.affiliation: Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil.
authors.forename: Paulo Ha
authors.initials: PH
authors.lastname: Jardim
authors.affiliation: Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil.
authors.forename: Stephanie C
authors.initials: SC
authors.lastname: Lima
authors.affiliation: Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil.
authors.forename: Paula V
authors.initials: PV
authors.lastname: Leal
authors.affiliation: Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil. fabricio.frazilio@ufms.br.
authors.forename: Fabrício O
authors.initials: FO
authors.lastname: Frazílio
mesh_terms: D000577:Amides; D000758:Anesthesia / Q000662:veterinary*; D000779:Anesthetics, Local; D000818:Animals; D002045:Bupivacaine / Q000031:analogs & derivatives*; D005260:Female; D000077554:Levobupivacaine; D008012:Lidocaine; D008161:Lumbosacral Region; D009407:Nerve Block / Q000379:methods / Q000662:veterinary*; D000077212:Ropivacaine; D012756:Sheep; D013904:Thoracic Vertebrae
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine; D008012:Lidocaine; D000077554:Levobupivacaine; D002045:Bupivacaine
keywords: cardiopulmonary; paravertebral; regional anesthesia; sheep