Xylazine Premedication does not Modify the Onset and Duration of Cisatracurium Blockade in Anaesthetized Dogs

Abstract

The purpose of this study was to evaluate the effect of xylazine as premedication on the onset time and duration of cisatracurium neuromuscular blockade in anaesthetized dogs. This study was carried out on 12 healthy dogs aged 0.5-6 years and weighing 9-26 kg undergoing various elective surgical procedures. The dogs were randomly divided into two groups of t (test) and c (control), with six dogs each. In group t, premedication was conducted using acepromazine maleate 0.3 mg kg(-1) and xylazine 0.3 mg kg(-1) and in group c only acepromazine (same dose) was injected intramuscularly 20 min before general anaesthesia. After induction with thiopental, anaesthesia was maintained with halothane in oxygen to deliver an end-tidal halothane concentration of 1.1%. Neuromuscular blockade was induced with cisatracurium 0.2 mg kg(-1) and monitored using the train-of-four (TOF) stimulation pattern applied at the ulnar nerve. The onset time of cisatracurium blockade was 195 +/- 85.44 s in test and 153.3 +/- 38.16 s in control group. The duration of neuromuscular blockade was 24.8 +/- 4.79 min in t and 28.3 +/- 5.46 min in the c group. Statistical analysis of the data showed no significant difference between groups in terms of onset and duration of neuromuscular blockade.

Onset and duration of cis‐atracurium neuromuscular block during fentanyl and lidocaine infusions in isoflurane‐anaesthetised dogs

“…The possible cis-atracurium potentiation by fentanyl and lidocaine did not influence the duration of the NMB, which was shorter in dogs administered fentanyl. Accordingly, the duration of the NMB was similar to that described in other studies for isoflurane-anaesthetised (27 (24–31) minutes)4 and halothane-anaesthetised dogs (28.3±10.2 minutes and 28.3±5.46 minutes) 1 20. In addition, the body temperature of dogs administered fentanyl was, among groups, the most adequate for the species.…”

“…In previous studies, the NMB onset after cis-atracurium was longer in dogs administered acepromazine (2.5±0.6 minutes and 6.2±1.4 minutes),1 20 dexmedetomidine (3.8 (2.6–5) minutes)4 and acepromazine plus xylazine (3.2±1.4 minutes)20 compared with the present study. Alpha-2 adrenoceptor drugs produce central muscle relaxation through inhibition of noradrenaline release in interneurons of the spinal cord, which can potentiate the NMB effects of a nondepolarising muscle relaxant 15 20. However, the significant, despite poor, positive correlation between the dose of medetomidine and the onset time of the NMB was not considered to be the primary cause of the reduction of the NMB onset.…”

“…In addition to the dose of cis-atracurium, the onset time of the NMB can be influenced by other drugs that affect muscle contractility and/or cardiac output, such as benzodiazepines,19 acepromazine,20 alpha-2 adrenoceptor agonist drugs,15 20 propofol,21–23 inhalant agents23 and lidocaine 24. In previous studies, the NMB onset after cis-atracurium was longer in dogs administered acepromazine (2.5±0.6 minutes and 6.2±1.4 minutes),1 20 dexmedetomidine (3.8 (2.6–5) minutes)4 and acepromazine plus xylazine (3.2±1.4 minutes)20 compared with the present study. Alpha-2 adrenoceptor drugs produce central muscle relaxation through inhibition of noradrenaline release in interneurons of the spinal cord, which can potentiate the NMB effects of a nondepolarising muscle relaxant 15 20.…”

Neuromuscular blockade effects of cisatracurium in 11 cats undergoing ophthalmological surgery anaesthetised with isoflurane

“…5 Data from the latter study indicated that the onset time of the NMB induced by cis-atracurium can be shortened in isoflurane-anaesthetised dogs administered fentanyl and lidocaine. 5 It can also be influenced by others drugs that affect muscle contractility and/or cardiac output, such as benzodiazepines, 6 acepromazine, 7 alpha-2 adrenoceptor agonist drugs, 7,8 propofol 9,10 and inhalant agents. 10,11 To date, there has been no study in cats comparing cisatracurium and different anaesthetic protocols.…”

Effects of Cisatracurium in Sevoflurane and Propofol Requirements in Dog-Undergoing-Mastectomy Surgery

“…Anesthesia was induced with propofol (Proposure 10 mg mL −1 ; Boehringer Ingelheim Animal Health Italia SpA, Noventana (PD), Italy) at the dosage of 4–6 mg kg −1 intra-venously (IV) to effect. In Group B, the administration of propofol was immediately followed by a single IV bolus injection of cisatracurium 0.2 mg kg −1 (Nimbex 2 mg mL −1 Glaxo, SmithKline SpA, Verona, Italy) [ 3 , 7 , 14 ].…”