Dexmedetomidine constant rate infusion for 24 hours during and after propofol or isoflurane anaesthesia in dogs



      To evaluate cardiovascular and respiratory effects and pharmacokinetics of a 24-hour intravenous constant rate infusion (CRI) of dexmedetomidine (DMED) during and after propofol (PRO) or isoflurane (ISO) anaesthesia in dogs.

      Study design

      Prospective, randomized, cross-over study.


      Ten healthy adult Beagles.


      Instrumented dogs received a DMED-loading bolus (25 μg m−2) at time 0 followed by a 24-hour CRI (25 μg m−2 hour−1), with PRO or ISO induction/maintenance of anaesthesia during the first 2 hours (PRO and ISO treatment groups, respectively). Cardiovascular, respiratory, blood gas, airway gas, serum chemistry variables and DMED plasma concentration data were collected at -15, 5, 15, 30, 45, 60, 90 and 120 minutes. A number of cardiorespiratory and tissue oxygenation variables were calculated from the above data. After the 2-hours of anaesthesia, heart and respiratory rates and electrocardiograms were recorded and DMED plasma concentrations were determined for up to 26 hours.


      Vasopressor effects and the decrease in heart rate (HR) and cardiac index induced by DMED were greater for PRO than ISO, but were within clinically acceptable ranges. Adequate oxygenation was maintained above the critical O2 delivery level. The overall incidence of unfavourable arrhythmias was low and tended to vary inversely with HR. Mean DMED plasma concentration ranged from 0.23 to 0.47 ng mL−1 for both groups during the 24-hour CRI with a mean elimination half-life of approximately 0.46 hour.
      Conclusion and/clinical relevance DMED CRI resulted in typical α2-agonist induced haemodynamic changes with minimal respiratory effects, and appeared to be an efficacious adjunct during and after PRO or ISO anaesthesia in healthy dogs.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Veterinary Anaesthesia and Analgesia
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • De Backer D
        VO2/DO2 relationship: how to get rid of methodological pitfalls?.
        Intensive Care Med. 2000; 26: 1719-1722
        • Bloor BC
        • Frankland M
        • Alper G
        • et al.
        Hemodynamic and sedative effects of dexmedetomidine in dog.
        J Pharmacol Exp Ther. 1992; 263: 690-697
        • Dantzker DR
        Adequacy of tissue oxygenation.
        Crit Care Med. 1993; 21: S40-S43
        • Davies C
        Excitatory phenomena following the use of propofol in dogs.
        J Vet Anaesth. 1991; 18: 48-51
        • Flacke WE
        • Flacke JW
        • Bloor BC
        • et al.
        Effects of dexmedetomidine on systemic and coronary hemodynamics in the anesthetized dog.
        J Cardiothorac Vasc Anesth. 1993; 7: 41-49
        • Gomez-Villamandos RJ
        • Palacios C
        • Benitez A
        • et al.
        Dexmedetomidine or medetomidine premedication before propofol-desflurane anaesthesia in dogs.
        J Vet Pharmacol Ther. 2006; 29: 157-163
        • Gottrup F
        Physiology and measurement of tissue perfusion.
        Ann Chir Gynaecol. 1994; 83: 183-189
        • Hall LW
        • Lagerweij E
        • Nolan AM
        • et al.
        Effect of medetomidine on the pharmacokinetics of propofol in dogs.
        Am J Vet Res. 1994; 55: 116-120
        • Haskins S
        • Pascoe PJ
        • Ilkiw JE
        • et al.
        Reference cardiopulmonary values in normal dogs.
        Comp Med. 2005; 55: 156-161
        • Housmans PR
        Effects of dexmedetomidine on contractility, relaxation, and intracellular calcium transients of isolated ventricular myocardium.
        Anaesthesiology. 1990; 73: 919-922
        • Johnson KL
        Diagnostic measures to evaluate oxygenation in critically ill adults: implications and limitations.
        AACN Clin Issues. 2004; 15: 506-524
        • Keegan RD
        • Greene SA
        Cardiovascular effects of a continuous two-hour propofol infusion in dogs: comparison with isoflurane anesthesia.
        Vet Surg. 1993; 22: 537-543
        • Khan ZP
        • Munday IT
        • Jones RM
        • et al.
        Effects of dexmedetomidine on isoflurane requirements in healthy volunteers. 1: pharmacodynamic and pharmacokinetic interactions.
        Br J Anaesth. 1999; 83: 372-380
        • Kojima K
        • Nishimura R
        • Mutoh T
        • et al.
        Comparison of cardiopulmonary effects of medetomidine-midazolam, acepromazine-butorphanol and midazolam-butorphanol in dogs.
        Zentralbl Veterinarmed A. 1999; 46: 353-359
        • Kuo WC
        • Keegan RD
        Comparative cardiovascular, analgesic, and sedative effects of medetomidine, medetomidine-hydromorphone, and medetomidine-butorphanol in dogs.
        Am J Vet Res. 2004; 65: 931-937
        • Kuusela E
        • Raekallio M
        • Anttila M
        • et al.
        Clinical effects and pharmacokinetics of medetomidine and its enantiomers in dogs.
        J Vet Pharmacol Ther. 2000; 23: 15-20
        • Kuusela E
        • Raekallio M
        • Vaisanen M
        • et al.
        Comparison of medetomidine and dexmedetomidine as premedicants in dogs undergoing propofol-isoflurane anesthesia.
        Am J Vet Res. 2001; 62: 1073-1080
        • Kuusela E
        • Vainio O
        • Kaistinen A
        • et al.
        Sedative, analgesic, and cardiovascular effects of levomedetomidine alone and in combination with dexmedetomidine in dogs.
        Am J Vet Res. 2001; 62: 616-621
        • Kuusela E
        • Raekallio M
        • Hietanen H
        • et al.
        24-hour Holter-monitoring in the perianaesthetic period in dogs premedicated with dexmedetomidine.
        Vet J. 2002; 164: 235-239
        • Lagutchik MS
        • Ogilvie GK
        • Wingfield WE
        • et al.
        Lactate kinetics in veterinary critical care: a review.
        J Vet Emerg Crit Care. 1996; 6: 81-95
        • Lagutchik MS
        • Ogilvie GK
        • Hackett TB
        • et al.
        Increased lactate concentrations in ill and injured dogs.
        J Vet Emerg Crit Care. 1998; 8: 117-127
        • Lawrence CJ
        • Prinzen FW
        • De Lange S
        The effect of dexmedetomidine on the balance of myocardial energy requirement and oxygen supply and demand.
        Anesth Analg. 1996; 82: 544-550
        • Lawrence CJ
        • Prinzen FW
        • De Lange S
        The effect of dexmedetomidine on nutrient organ blood flow.
        Anesth Analg. 1996; 83: 1160-1165
        • Van Der Linden P
        • Gilbart E
        • Engelman E
        • et al.
        Effects of anesthetic agents on systemic critical O2 delivery.
        J Appl Physiol. 1991; 71: 83-93
        • Van Der Linden P
        • Schmartz D
        • Gilbart E
        • et al.
        Effects of propofol, etomidate, and pentobarbital on critical oxygen delivery.
        Crit Care Med. 2000; 28: 2492-2499
        • Meurs KM
        • Spier AW
        • Wright NA
        • et al.
        Use of ambulatory electrocardiography for detection of ventricular premature complexes in healthy dogs.
        J Am Vet Med Assoc. 2001; 218: 1291-1292
        • Pascoe PJ
        • Raekallio M
        • Kuusela E
        • et al.
        Changes in the minimum alveolar concentration of isoflurane and some cardiopulmonary measurements during three continuous infusion rates of dexmedetomidine in dogs.
        Vet Anaesth Analg. 2006; 33: 97-103
        • Reinhart K
        Monitoring of oxygen transport systems.
        Anaesthesist. 1988; 37: 1-9
        • Roekaerts PM
        • Prinzen FW
        • De Lange S
        Beneficial effects of dexmedetomidine in ischaemic myocardium of anesthetized dogs.
        Br J Anaesth. 1996; 77: 427-429
        • Salonen S
        • Vuorilehto L
        • Vainio O
        • et al.
        Atipamezole increases medetomidine clearance in the dog: an agonist-antagonist interaction.
        J Vet Pharmacol Ther. 1995; 18: 328-332
        • Schmeling WT
        • Kampine JP
        • Roerig DL
        • et al.
        The effects of the stereoisomers of the alpha 2-adrenergic agonist medetomidine on systemic and coronary hemodynamics in conscious dogs.
        Anesthesiology. 1991; 75: 499-511
        • Shehabi Y
        • Ruettimann U
        • Adamson H
        • et al.
        Dexmedetomidine infusion for more than 24 hours in critically ill patients: sedative and cardiovascular effects.
        Intensive Care Med. 2004; 30: 2188-2196
        • Sinclair MD
        A review of the physiological effects of alpha2-agonists related to the clinical use of medetomidine in small animal practice.
        Can Vet J. 2003; 44: 885-897
        • Tobias JD
        • Berkenbosch JW
        Sedation during mechanical ventilation in infants and children: dexmedetomidine versus midazolam.
        South Med J. 2004; 97: 451-455
        • Torres-Filho IP
        • Spiess BD
        • Pittman RN
        • et al.
        Experimental analysis of critical oxygen delivery.
        Am J Physiol Heart Circ Physiol. 2005; 288: H1071-H1079
        • Uilenreef JJ
        • Murrell JC
        • McKusick BC
        • et al.
        Dexmedetomidine continuous rate infusion during isoflurane anaesthesia in canine surgical patients.
        Vet Anaesth Analg. 2007; (In press.)
        • Ulloa HM
        • Houston BJ
        • Altrogge DM
        Arrhythmia prevalence during ambulatory electrocardiographic monitoring of beagles.
        Am J Vet Res. 1995; 56: 275-281
        • Wahlander S
        • Frumento RJ
        • Wagener G
        • et al.
        A prospective, double-blind, randomized, placebo-controlled study of dexmedetomidine as an adjunct to epidural analgesia after thoracic surgery.
        J Cardiothorac Vasc Anesth. 2005; 19: 630-635
        • Weitz JD
        • Foster SD
        • Waugaman WR
        • et al.
        Anesthetic and hemodynamic effects of dexmedetomidine during isoflurane anesthesia in a canine model.
        Nurse Anesth. 1991; 2: 19-27
        • White PF
        Clinical uses of intravenous anesthetic and analgesic infusion.
        Anesth Analg. 1989; 68: 161-171
        • Wilkinson PL
        • Moyers JR
        • Ports T
        • et al.
        Rate-pressure product and myocardial oxygen consumption during surgery for coronary artery bypass.
        Circulation. 1979; 60: 170-173
        • Willigers HM
        • Prinzen FW
        • Roekaerts PM
        Comparison of the effects of dexmedetomidine and esmolol on myocardial oxygen consumption in dogs.
        Eur J Anaesthesiol. 2004; 21: 957-966

      Uncited reference

        • Wiesemes R
        • Peters J
        The role of mixed venous oxygen saturation in perioperative monitoring and therapy: a critical stock taking.
        Anasthesiol Intensivmed Notfallmed Schmerzther. 1993; 28: 269-278