Effects of dexmedetomidine or tramadol continuous rate infusions on the propofol requirements and cardiorespiratory variables in propofol-ketamine-midazolam anaesthetised cats

The aim of this study was to compare the effects of midazolam-ketamine alone or in combination with dexmedetomidine or tramadol in a constant rate infusion (CRI) on the minimum infusion rate (MIR) of propofol and the cardiorespiratory function in cats undergoing an ovariohysterectomy (OH). This was a prospective, randomised, blinded clinical study. Twenty-four healthy female mixed-breed cats were premedicated with ketamine and midazolam. Propofol was used for the induction and maintenance of the anaesthesia (starting at 18 mg/kg/h). Cats were assigned to groups (n = 8) to receive one of the following intravenous treatments: midazolam-ketamine group (MKG; ketamine 0.6 mg/kg/h); midazolam-ketamine-dexmedetomidine group [MKDG; ketamine 0.6 mg/kg/h and dexmedetomidine loading dose (LD) 1 mg/kg, CRI 1 mg/kg/h)] or midazolam-ketamine-tramadol group [MKTG; ketamine 0.6 mg/kg/h and tramadol (LD 2 mg/kg, CRI 1 mg/kg/h)]. During the OH, the propofol infusion was adjusted based on the clinical signs to maintain adequate anaesthetic depth. Selected variables were measured before (T0) and after (T1) the anaesthesia induction and during six surgical time points (T2–T7). The mean arterial pressure was higher and the heart rate was lower in MKDG at T1 (than in MKG and MKTG). The mean ± SD MIR of propofol were 17.4 ± 3.2, 15.0 ± 2.8 and 12.6 ± 3.5 mg/kg/h for MKG, MKTG, and MKDG, respectively. We conclude that, compared to midazolam-ketamine alone, midazolam-ketamine-tramadol and midazolam-ketamine-dexmedetomidine reduced the MRI of propofol by 13.8% and 27.5%, respectively, without significant changes in the selected indicators.

[1]  M. Raffe Total Intravenous Anesthesia for the Small Animal Critical Patient. , 2020, The Veterinary clinics of North America. Small animal practice.

[2]  C. Mahidol,et al.  Evaluating the effects of continuous intravenous infusions of tramadol and tramadol-lidocaine on sevoflurane minimum alveolar concentration (MAC) and entropy values in dogs , 2019, The Journal of veterinary medical science.

[3]  B. Simon,et al.  The clinical effects of a low dose dexmedetomidine constant rate infusion in isoflurane anesthetized cats. , 2018, Veterinary journal.

[4]  C. M. Moreira,et al.  Effect of administration rate on propofol requirement in cats , 2017, Journal of feline medicine and surgery.

[5]  A. Mathis Practical guide to monitoring anaesthetised small animal patients , 2016, In Practice.

[6]  R. Rezende,et al.  Cardiopulmonary and acid-base effects of tramadol in cats anesthetized with sevoflurane = Efeito cardiopulmonar e ácido básico do tramadol em gatas anestesiadas pelo sevoflurano , 2016 .

[7]  Nilson Oleskovicz,et al.  Continuous infusion of propofol at variable rates in a time dependent in cats , 2015 .

[8]  C. Mahidol,et al.  Effects of continuous intravenous infusion of morphine and morphine-tramadol on the minimum alveolar concentration of sevoflurane and electroencephalographic entropy indices in dogs. , 2015, Veterinary anaesthesia and analgesia.

[9]  B. Ambros,et al.  Effect of low dose rate ketamine infusions on thermal and mechanical thresholds in conscious cats. , 2013, Veterinary anaesthesia and analgesia.

[10]  P. Cagnardi,et al.  Pharmacokinetics of ketamine and propofol combination administered as ketofol via continuous infusion in cats. , 2012, Journal of veterinary pharmacology and therapeutics.

[11]  D. Doyle,et al.  The use of dexmedetomidine in anesthesia and intensive care: a review. , 2012, Current pharmaceutical design.

[12]  M. Gelain,et al.  Evaluation of a ketamine-propofol drug combination with or without dexmedetomidine for intravenous anesthesia in cats undergoing ovariectomy. , 2012, Journal of the American Veterinary Medical Association.

[13]  E. R. Monteiro,et al.  Minimum infusion rate and hemodynamic effects of propofol, propofol-lidocaine and propofol-lidocaine-ketamine in dogs. , 2012, Veterinary anaesthesia and analgesia.

[14]  H. Muhammad,et al.  The effect of dexmedetomidine on the adjuvant propofol requirement and intraoperative hemodynamics during remifentanil-based anesthesia , 2012, Korean journal of anesthesiology.

[15]  B. Pypendop,et al.  Hemodynamic effects of dexmedetomidine in isoflurane-anesthetized cats. , 2011, Veterinary anaesthesia and analgesia.

[16]  G. Luvoni,et al.  Pharmacokinetics, intraoperative effect and postoperative analgesia of tramadol in cats. , 2011, Research in veterinary science.

[17]  R. Dias,et al.  Cardiopulmonary and isoflurane-sparing effects of epidural or intravenous infusion of dexmedetomidine in cats undergoing surgery with epidural lidocaine. , 2010, Veterinary anaesthesia and analgesia.

[18]  B. Nossaman,et al.  Dexmedetomidine: a review of clinical applications , 2008, Current opinion in anaesthesiology.

[19]  M. Payton,et al.  Effect of orally administered tramadol alone or with an intravenously administered opioid on minimum alveolar concentration of sevoflurane in cats. , 2008, Journal of the American Veterinary Medical Association.

[20]  B. Pypendop,et al.  Pharmacokinetics of tramadol, and its metabolite O-desmethyl-tramadol, in cats. , 2007, Journal of veterinary pharmacology and therapeutics.

[21]  P. Pascoe,et al.  Effect of variable-dose propofol alone and in combination with two fixed doses of ketamine for total intravenous anesthesia in cats. , 2003, American journal of veterinary research.

[22]  H. Luk,et al.  Propofol inhibits medullary pressor mechanisms in cats , 1997, Canadian journal of anaesthesia = Journal canadien d'anesthesie.