Dexmedetomidine for perioperative management of five dogs submitted to a pheochromocytoma ablation

Dexmedetomidine for perioperative management of five dogs submitted to a pheochromocytoma ablation Lambertini C., Joechler M, Foglia A., Romagnoli N. Department of Veterinary Medical Sciences, Alma Mater Studiorum - University of Bologna,. Via Tolara di Sopra 50 - 40064 Ozzano dell’Emilia (BO), Italy. Pheochromocytoma (PHEO) ablation produces severe cardiovascular complications. In humans dexmedetomidine minimizes hemodynamic alterations during surgical PHEO manipulation (Singh and Singh 2014). Five mixed breed dogs undergoing adrenalectomy for PHEO were premedicated with dexmedetomidine (1g kg-1) and methadone (0.2 mg kg-1) IM. Anaesthesia was induced with propofol IV and maintained with isoflurane in oxygen. Dexmedetomidine (0.5 g kg-1 h-1) and remifentanil (3 g kg-1 min-1) or fentanyl (5-10 g kg-1 h-1) were administered IV. Cardiorespiratory parameters were monitored throughout the procedure. After extubation, dexmedetomidine was discontinued and post-operative analgesia was provided by methadone (0.1 mg kg-1) IM. Episode of hypotension, hypertension and arrhythmias were recorded and quantified. Data were analyzed with a descriptive statistic and are shown as mean  SD. In all dogs, sedation and induction were smooth without hemodynamic alterations. The mean HR intraopearively was 77.9  15.9 beats min-1 and the mean MAP was 75.1  4.7 mmHg. One dog experienced atrioventricular blocks and a transient increase in blood pressure up to a MAP of 125 mmHg. Two dogs experienced transient hypotension (MAP 50 mmHg):one dog was treated with crystalloid administration; but in the other one dobutamine was administered IV. All dogs were discharged within 10 days. Perioperative administration of dexmedetomidine along with remifentanil or fentanyl in dogs with PHEO provided satisfactory sedation and analgesia. In addition dexmedetomidine, by means of its effect of inhibition of catecholamines’ outflow (Moura et al. 2006; Jung et al. 2012), prevented significant alteration in HR and blood pressure during mass manipulation. References Moura E, Afonso J, Hein L et al. (2006) α2-adrenoceptor subtypes involved in the regulation of catecholamine release from the adrenal medulla of mice. Br J Pharmacol 149, 1049-1058. Jung JW, Park JK, Jeon SY et al. (2012) Dexmedetomidine and remifentanil in the perioperative management of an adolescent undergoing resection of pheochromocytoma -A case report- Korean J Anesthesiol 63, 555–558. Singh S & Singh A (2014) Dexmedetomidine induced catecholamine suppression in pheochromocytoma. J Nat Sci Biol Med 5, 182-183.