Perioperative analgesic effects of the erector spinae plane block with bupivacaine or bupivacaine-dexmedetomidine in dogs undergoing hemilaminectomy: A randomized controlled trial.

Objective: To compare the perioperative opioid requirements among dogs receiving an erector spinae plane (ESP) block with bupivacaine, with or without dexmedetomidine, and a control group. Animals and procedure: Thirty client-owned, healthy adult dogs undergoing hemilaminectomy were included in this randomized, prospective, blinded clinical study. Dogs were randomly assigned to 1 of 3 treatment groups: Group B, ESP block with bupivacaine; Group BD, ESP block with bupivacaine and dexmedetomidine; and Group C, control. Rescue intra- and postoperative analgesia consisted of fentanyl and methadone, respectively. Postoperative pain was evaluated using the short form of the Glasgow Composite Measure Pain Scale (CMPS-SF). Results: In Group BD, 0/10 dogs required intraoperative fentanyl, compared to 9/10 in Group C (P < 0.001), whereas 1/10 required postoperative methadone, compared to 9/10 in Group B (P = 0.003) and 10/10 in Group C (P < 0.001). The total amount of intraoperative fentanyl (µg/kg) was 0 (0 to 4) in Group B and 0 (0 to 0) in BD, compared to 6 (0 to 8) in C (P = 0.004 and P < 0.001, respectively). Postoperative methadone (mg/kg) required during the first 12 h was 0.5 (0 to 1.4) in Group B (P = 0.003) and 0 (0 to 0) in BD (P < 0.001), compared to C (P = 0.003 and P < 0.001, respectively). Conclusion: An ESP block with bupivacaine, with or without dexmedetomidine, was associated with a reduction in perioperative opioid consumption and provided effective acute pain control.

Effets analgésiques périopératoires du bloc des érecteurs du rachis avec de la bupivacaïne ou de la bupivacaïne-dexmédétomidine chez les chiens subissant une hémilaminectomie: un essai contrôlé randomisé. Objectif: Comparer les besoins périopératoires en opioïdes chez les chiens recevant un bloc des érecteurs de la colonne vertébrale (ESP) avec de la bupivacaïne, avec ou sans dexmédétomidine, et un groupe témoin. Animaux et procédure: Trente chiens adultes en bonne santé appartenant à des clients subissant une hémilaminectomie ont été inclus dans cette étude clinique randomisée, prospective et en aveugle. Les chiens ont été répartis au hasard dans 1 des 3 groupes de traitement: groupe B, bloc ESP avec bupivacaïne; groupe BD, bloc ESP avec bupivacaïne et dexmédétomidine; et groupe C, témoin. L'analgésie de secours peropératoire et postopératoire consistait respectivement en fentanyl et en méthadone. La douleur postopératoire a été évaluée à l'aide du formulaire abrégé de l'échelle de mesure de la douleur de Glasgow (CMPS-SF). Résultats: Dans le groupe BD, 0/10 chiens ont eu besoin de fentanyl peropératoire, contre 9/10 dans le groupe C (P < 0,001), tandis que 1/10 ont eu besoin de méthadone postopératoire, contre 9/10 dans le groupe B (P = 0,003) et 10/10 dans le groupe C (P < 0,001). La quantité totale de fentanyl peropératoire (µg/kg) était de 0 (0 à 4) dans le groupe B et de 0 (0 à 0) dans le groupe BD, contre 6 (0 à 8) dans le groupe C (P = 0,004 et P < 0,001, respectivement). La méthadone postopératoire (mg/kg) nécessaire au cours des 12 premières heures était de 0,5 (0 à 1,4) dans le groupe B (P = 0,003) et de 0 (0 à 0) dans le groupe BD (P < 0,001), par rapport au groupe C (P = 0,003). et P < 0,001, respectivement). Conclusion: Un bloc ESP avec de la bupivacaïne, avec ou sans dexmédétomidine, a été associé à une réduction de la consommation peropératoire d'opioïdes et a permis un contrôle efficace de la douleur aiguë.(Traduit par Dr Serge Messier).

Plasma histamine concentrations in horses administered sodium penicillin, guaifenesin-xylazine-ketamine and isoflurane with morphine or butorphanol.

OBJECTIVE: Various drugs administered to horses undergoing surgical procedures can release histamine. Histamine concentrations were evaluated in horses prepared for surgery and administered butorphanol or morphine intraoperative infusions. STUDY DESIGN: Prospective studies with one randomized. ANIMALS: A total of 44 client-owned horses. METHODS: In one study, anesthesia was induced with xylazine followed by ketamine-diazepam. Anesthesia was maintained with guaifenesin-xylazine-ketamine (GXK) during surgical preparation. For surgery, isoflurane was administered with intravenous (IV) morphine (group M: 0.15 mg kg-1 and 0.1 mg kg-1 hour-1; 15 horses) or butorphanol (group B: 0.05 mg kg-1 and 0.01 mg kg-1 hour-1; 15 horses). Histamine and morphine concentrations were measured using enzyme-linked immunoassay before opioid injection (time 0), and after 1, 2, 5, 30, 60 and 90 minutes. In a subsequent study, plasma histamine concentrations were measured in 14 horses before drug administration (baseline), 15 minutes after IV sodium penicillin and 15 minutes after starting GXK IV infusion. Statistical comparison was performed using anova for repeated measures. Pearson correlation compared morphine and histamine concentrations. Data are presented as mean ± standard deviation. Significance was assumed when p ≤ 0.05. RESULTS: With histamine, differences occurred between baseline (3.2 ± 2.4 ng mL-1) and GXK (5.2 ± 7.1 ng mL-1) and between baseline and time 0 in group B (11.9 ± 13.4 ng mL-1) and group M (11.1 ± 12.4 ng mL-1). No differences occurred between baseline and after penicillin or between groups M and B. Morphine concentrations were higher at 1 minute following injection (8.1 ± 5.1 ng mL-1) than at 30 minutes (4.9 ± 3.1 ng mL-1) and 60 minutes (4.0 ± 2.5 ng mL-1). Histamine correlated with morphine at 2, 30 and 60 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: GXK increased histamine concentration, but concentrations were similar with morphine and butorphanol.

The effect of body condition on alfaxalone induction dosage requirement in dogs.

Background: Alfaxalone is commonly used in veterinary anesthesia for the induction of general anesthesia (GA) in dogs. However, it has been associated with dose-dependent cardiovascular depression. Therefore, the administration of liposoluble, intravenous (IV)-administered injectable induction agents, such as alfaxalone, is recommended to be based on the dog's lean body mass (LBM). Aim: To determine the influence of body condition score (BCS) on IV alfaxalone dose requirements to achieve endotracheal intubation in dogs. Methods: Prospective clinical study. A group of 34 dogs undergoing GA for diagnostic and/or surgical procedures, body weight (BW) > 4 kg, BCS > 2, age 1-14 years, American Society of Anesthesiologists (ASAs) classification I-III. Dogs were allocated to two different groups according to their BCS: non-overweight group (NOW) BCS: 3-5 and over-weight group (OW) BCS: 6-9. All dogs were premedicated IV with methadone 0.2 mg kg-1, and anesthesia was induced by a slow IV infusion of alfaxalone at 1 mg kg-1 minute-1, delivered with a syringe driver, until loss of jaw tone and no/minimal gagging reflex sufficient to allow endotracheal intubation was achieved. The total dose of alfaxalone and the occurrence of post-induction apnoea were recorded.The Shapiro-Wilk test was performed to test for normality. A Chi-square test was performed to compare the incidence of post-induction apnoea between groups, and the Mann-Whitney U test was performed to compare the induction dose of alfaxalone between groups. A p-value < 0.05 was considered statistically significant. Results: The mean dose ± standard deviation of alfaxalone in NOW was 2.18 ± 0.59 mg kg-1, and in OW, it was 1.63 ± 0.26 mg kg-1 (p = 0.002). The sedation score did not differ between groups. Postinduction apnoea (PIA) occurred in 6 of 17 animals in NOW and 15 of 17 in OW (p = 0.002). Conclusion: The dose of IV alfaxalone per kg of total body mass required to achieve endotracheal intubation was lower in overweight dogs, suggesting that LBM should be considered when calculating IV anesthetic doses. The incidence of post-induction apnoea was higher in overweight/obese dogs with alfaxalone administered at a rate of 1 mg kg-1 minute-1.

Standing sedation management of a domesticated reindeer for third eyelid removal.

Background: Reindeer are becoming popular animals within petting farms. Few case reports describe the sedation of domesticated reindeer, but none describe the use of ocular local anesthetic blocks in this species. Case Description: A 9-year-old, female, Svalbard reindeer (Rangifer tarandus platyrhynchus) presenting for removal of a squamous cell carcinoma involving the third eyelid. Standing sedation was performed using initial boluses of medetomidine and butorphanol via intramuscular injection before catheter placement and maintenance with a variable rate infusion of medetomidine. Supraorbital, auriculopalpebral, infratrochlear blocks and local infiltration of the base of the third eyelid were performed using mepivacaine. Following the surgical removal of the third eyelid, atipamazole was administered intramuscularly to antagonize the effects of medetomidine. The patient recovered without complications. Conclusion: Medetomidine-butorphanol in combination with local anesthetic blocks provided a sufficient plane of sedation and analgesia for extra ocular surgery in a domesticated reindeer.

Assessment of an ultrasound-guided technique for catheterization of the caudal thoracic paravertebral space in dog cadavers.

Background: The caudal thoracic paravertebral (CTPV) block is a regional anesthesia technique currently used in human medicine to provide analgesia in abdominal surgical procedures. Aim: The objectives of this study are to describe an ultrasound-guided technique to place catheters in CTPV space in canine cadavers and evaluate the distribution of a 50:50 contrast-dye solution administered through them. Methods: Eight thawed adult beagle cadavers (9.2 ± 2.0 kg body total weight) were used. Thirteen catheters were placed. In the first phase, a volume of 0.3 ml kg-1 of the contrast-dye was administered in all cases. After the injections, computed tomography (CT) scans were carried out to assess the distribution of the contrast-dye. In the second phase, an extra 0.2 ml kg-1 of the contrast-dye was administered through eight catheters, followed by a second CT scan. Two cadavers were dissected to assess the distribution of the contrast-dye. The injection site varied between T8-9 and T12-13. Results: The evaluation of the CT scans showed contrast-dye within the paravertebral space in 92% (12/13) of the injections. The distribution pattern observed after the injections performed within the TPV space was linear and intercostal in all cases. The median (range) linear spread of the contrast was 7 (5-10) spinal nerves and involved 3 (2-8) intercostal spaces. The contrast-dye reached lumbar regions in 42% of the injections (5/12). A larger spread of the contrast-dye was not observed after the administration of a second dose of the injectate. No signs of epidural, intrapleural/intrapulmonary, intravascular, or intraabdominal spread were observed. The dissection of the two cadavers confirmed the spread of the contrast-dye along the sympathetic trunk and intercostal spaces. Conclusion: The administration of 0.3 ml kg-1 of the contrast-dye in the CTPV space resulted in a distribution compatible with the block of nerves responsible for the innervation of the majority of the abdominal viscera and cranial abdominal wall.