Microcirculation assessment of dexmedetomidine constant rate infusion during anesthesia of dogs with sepsis from pyometra: a randomized clinical study



      To compare dexmedetomidine and fentanyl constant rate infusions in anesthetic protocols for septic dogs with pyometra, using microcirculatory, hemodynamic and metabolic variables.

      Study design

      Randomized clinical study.


      A total of 33 dogs with pyometra with two or more systemic inflammatory response syndrome variables undergoing ovariohysterectomy.


      Dogs were randomized into two groups: group DG, dexmedetomidine (3 μg kg–1 hour–1; 17 dogs) and group FG, fentanyl (5 μg kg–1 hour–1; 16 dogs) infused during isoflurane anesthesia and mechanical ventilation. Microcirculation flow index (MFI), total vessel density and De Backer score were assessed using orthogonal polarization spectral imaging at the sublingual site. Heart rate, invasive blood pressure, temperature, arterial blood gas analysis and lactate concentration were obtained at various time points. Variables were recorded at baseline (BL), immediately before (T0), 30 (T30) and 60 (T60) minutes after infusion, and 60 minutes after surgery. Data were analyzed using the Shapiro-Wilk test. To compare variables between groups, the unpaired Student t test was used. Comparison between evaluation time points was performed with two-way anova for repeated measures. Where statistical significance was detected, the Bonferroni post hoc test was used.


      MFI was significantly higher in group FG at T30. Mean arterial pressure at T30 was higher in group DG (89 ± 15 mmHg) than in group FG (72 ± 13 mmHg). Lactate concentrations were not significantly different between groups at each time point. Both groups had similar clinical outcomes (mortality, extubation time and occurrence of hypotension and bradyarrhythmias).

      Conclusions and clinical relevance

      Dexmedetomidine (3 μg kg–1 hour–1) without a loading dose can be included in the maintenance of anesthesia in dogs with pyometra and sepsis without compromising microcirculation and hemodynamic values when compared with fentanyl (5 μg kg–1 hour–1).


      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


        • Bao N.
        • Tang B.
        Organ-protective effects and the underlying mechanism of dexmedetomidine.
        Mediators Inflamm. 2020; 20206136105
        • Boller E.M.
        • Otto C.M.
        Sepsis and septic shock.
        in: Silverstein D.C. Hopper K. Small Animal Critical Care Medicine. 2nd edn. Elsevier/Saunders, USA2015: 472-480
        • De Backer D.
        • Creteur J.
        • Preiser J.C.
        • et al.
        Microvascular blood flow is altered in patients with sepsis.
        Am J Respir Crit Care Med. 2002; 166: 98-104
        • Diniz M.S.
        • Teixeira-Neto F.J.
        • Cândido T.D.
        • et al.
        Effects of dexmedetomidine on pulse pressure variation changes induced by hemorrhage followed by volume replacement in isoflurane-anesthetized dogs.
        J Vet Emerg Crit Care (San Antonio). 2014; 24: 681-692
        • Fantoni D.T.
        • Ida K.K.
        • Gimenes A.M.
        • et al.
        Pulse pressure variation as a guide for volume expansion in dogs undergoing orthopedic surgery.
        Vet Anaesth Analg. 2017; 44: 710-718
        • Flacke W.E.
        • Flacke J.W.
        • Bloor B.C.
        • et al.
        Effects of dexmedetomidine on systemic and coronary hemodynamics in the anesthetized dog.
        J Cardiothorac Vasc Anesth. 1993; 7: 41-49
        • Groner W.
        • Winkelman J.W.
        • Harris A.G.
        • et al.
        Orthogonal polarization spectral imaging: a new method for study of the microcirculation.
        Nat Med. 1999; 5: 1209-1212
        • Hagman R.
        Pyometra in small animals.
        Vet Clin North Am Small Anim Pract. 2018; 48: 639-661
        • Hauptman J.G.
        • Walshaw R.
        • Olivier N.B.
        Evaluation of the sensitivity and specificity of diagnostic criteria for sepsis in dogs.
        Vet Surg. 1997; 26: 393-397
        • Ince C.
        The microcirculation is the motor of sepsis.
        Crit Care. 2005; 9: S13-S19
        • Ince C.
        • Boerma E.C.
        • Cecconi M.
        • et al.
        Second consensus on the assessment of sublingual microcirculation in critically ill patients: results from a task force of the European Society of Intensive Care Medicine.
        Intensive Care Med. 2018; 44: 281-299
        • Kara A.
        • Akin S.
        • Ince C.
        Monitoring microcirculation in critical illness.
        Curr Opin Crit Care. 2016; 22: 444-452
        • Keene B.W.
        • Atkins C.E.
        • Bonagura J.D.
        • et al.
        ACVIM consensus guidelines for the diagnosis and treatment of myxomatous mitral valve disease in dogs.
        J Vet Intern Med. 2019; 33: 1127-1140
        • Kubitz J.C.
        • Forkl S.
        • Annecke T.
        • et al.
        Systolic pressure variation and pulse pressure variation during modifications of arterial pressure.
        Intensive Care Med. 2008; 34: 1520-1524
        • Lawrence C.J.
        • Prinzen F.W.
        • de Lange S.
        The effect of dexmedetomidine on nutrient organ blood flow.
        Anesth Analg. 1996; 83: 1160-1165
        • Lin G.Y.
        • Robben J.H.
        • Murrell J.C.
        • et al.
        Dexmedetomidine constant rate infusion for 24 hours during and after propofol or isoflurane anaesthesia in dogs.
        Vet Anaesth Analg. 2008; 35: 141-153
        • Liu X.
        • Zhang K.
        • Wang W.
        • et al.
        Dexmedetomidine versus propofol sedation improves sublingual microcirculation after cardiac surgery: a randomized controlled trial.
        J Cardiothorac Vasc Anesth. 2016; 30: 1509-1515
        • Liu X.
        • Xie G.
        • Zhang K.
        • et al.
        Dexmedetomidine vs propofol sedation reduces delirium in patients after cardiac surgery: a meta-analysis with trial sequential analysis of randomized controlled trials.
        J Crit Care. 2017; 38: 190-196
        • MacMillan L.B.
        • Hein L.
        • Smith M.S.
        • et al.
        Central hypotensive effects of the alpha2a-adrenergic receptor subtype.
        Science. 1996; 273: 801-803
        • Mathews K.
        • Kronen P.
        • Lascelles D.
        • et al.
        Guidelines for recognition, assessment and treatment of pain: WSAVA global pain council members and co-authors of this document.
        J Small Anim Pract. 2014; 55: E10-E68
        • Miranda M.L.
        • Balarini M.M.
        • Bouskela E.
        Dexmedetomidine attenuates the microcirculatory derangements evoked by experimental sepsis.
        Anesthesiology. 2015; 122: 619-630
        • Naaz S.
        • Ozair E.
        Dexmedetomidine in current anaesthesia practice- a review.
        J Clin Diagn Res. 2014; 8: GE01-GE04
        • Otto C.
        Sepsis in veterinary patients: what do we know and where can we go?.
        J Vet Emerg Crit Care. 2007; 17: 329-332
        • Pascoe P.J.
        • 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
        • Purvis D.
        • Kirby R.
        Systemic inflammatory response syndrome: septic shock.
        Vet Clin North Am Small Anim Pract. 1994; 24: 1225-1247
        • Pypendop B.H.
        • Verstegen J.P.
        Hemodynamic effects of medetomidine in the dog: a dose titration study.
        Vet Surg. 1998; 27: 612-622
        • Silverstein D.C.
        • Pruett-Saratan A.
        • Drobatz K.J.
        Measurements of microvascular perfusion in healthy anesthetized dogs using orthogonal polarization spectral imaging.
        J Vet Emerg Crit Care (San Antonio). 2009; 19: 579-587
        • Simões C.R.
        • Monteiro E.R.
        • Rangel J.P.
        • et al.
        Effects of a prolonged infusion of fentanyl, with or without atropine, on the minimum alveolar concentration of isoflurane in dogs.
        Vet Anaesth Analg. 2016; 43: 136-144
        • Smith F.O.
        Canine pyometra.
        Theriogenology. 2006; 66: 610-612
        • Trzeciak S.
        • Cinel I.
        • Dellinger R.P.
        • et al.
        Resuscitating the microcirculation in sepsis: the central role of nitric oxide, emerging concepts for novel therapies, and challenges for clinical trials.
        Acad Emerg Med. 2008; 15: 399-413
        • Uilenreef J.J.
        • Murrell J.C.
        • McKusick B.C.
        • Hellebrekers L.J.
        Dexmedetomidine continuous rate infusion during isoflurane anaesthesia in canine surgical patients.
        Vet Anaesth Analg. 2008; 35: 1-12
        • Valtolina C.
        • Robben J.H.
        • Uilenreef J.
        • et al.
        Clinical evaluation of the efficacy and safety of a constant rate infusion of dexmedetomidine for postoperative pain management in dogs.
        Vet Anaesth Analg. 2009; 36: 369-383
        • van Oostrom H.
        • Doornenbal A.
        • Schot A.
        • et al.
        Neurophysiological assessment of the sedative and analgesic effects of a constant rate infusion of dexmedetomidine in the dog.
        Vet J. 2011; 190: 338-344
        • Vickery R.G.
        • Sheridan B.C.
        • Segal I.S.
        • Maze M.
        Anesthetic and hemodynamic effects of the stereoisomers of medetomidine, an alpha 2-adrenergic agonist, in halothane-anesthetized dogs.
        Anesth Analg. 1988; 67: 611-615
        • Weerink M.A.S.
        • Struys M.M.R.F.
        • Hannivoort L.N.
        • et al.
        Clinical pharmacokinetics and pharmacodynamics of dexmedetomidine.
        Clin Pharmacokinet. 2017; 56: 893-913
        • Yu T.
        • Li Q.
        • Liu L.
        • et al.
        Different effects of propofol and dexmedetomidine on preload dependency in endotoxemic shock with norepinephrine infusion.
        J Surg Res. 2015; 198: 185-191
        • Zamani M.M.
        • Keshavarz-Fathi M.
        • Fakhri-Bafghi M.S.
        • et al.
        Survival benefits of dexmedetomidine used for sedating septic patients in intensive care setting: a systematic review.
        J Crit Care. 2016; 32: 93-100