Dexmedetomidine or medetomidine premedication before propofol–desflurane anaesthesia in dogs

Abstract

The objective of this study was to evaluate dexmedetomidine as a premedicant in dogs prior to propofol-desflurane anaesthesia, and to compare it with medetomidine. Six healthy dogs were anaesthetized. Each dog received intravenously (i.v.) five preanaesthetic protocols: D1 (dexmedetomidine, 1 microg/kg, i.v.), D2 (dexmedetomidine, 2 microg/kg, i.v.), M1 (medetomidine, 1 microg/kg, i.v.), M2 (medetomidine, 2 microg/kg, i.v.), or M4 (medetomidine, 4 microg/kg, i.v.). Anaesthesia was induced with propofol (2.3-3.3 mg/kg) and maintained with desflurane. The following variables were studied: heart rate (HR), mean arterial pressure, systolic arterial pressure, diastolic arterial pressure, respiratory rate (RR), arterial oxygen saturation, end-tidal CO2, end-tidal concentration of desflurane (EtDES) required for maintenance of anaesthesia and tidal volume. Arterial blood pH (pHa) and arterial blood gas tensions (PaO2, PaCO2) were measured during anaesthesia. Time to extubation, time to sternal recumbency and time to standing were also recorded. HR and RR decreased significantly during sedation in all protocols. Cardiorespiratory variables during anaesthesia were statistically similar for all protocols. EtDES was significantly different between D1 (8.1%) and D2 (7.5%), and between all doses of medetomidine. Desflurane requirements were similar for D1 and M2, and for D2 and M4 protocols. No statistical differences were observed in recovery times. The combination of dexmedetomidine, propofol and desflurane appears to be effective for induction and maintenance of general anaesthesia in healthy dogs.

Hemodynamic influence of acepromazine or dexmedetomidine premedication in isoflurane-anesthetized dogs

“…Kersten et al 23 reported that dogs given dexmedetomidine PO followed by isoflurane had decreased MABP and SVR, increased heart rate, and no change in CO. Similar cardiovascular effects were reported by Gomez-Villamandoz et al 24 In that study, 24 dogs were premedicated with 1.0 or 2.0 µg of dexmedetomidine/kg (0.45 to 0.9 µg/lb), IV, and anesthesia was induced with propofol (2.3 to 3.3 mg/kg [1.05 to 1.5 mg/lb], IV) and maintained with desflurane. The results of our study are similar to those reports.…”

Hemodynamics and bispectral index (BIS) of dogs anesthetized with midazolam and ketamine associated with medetomidine or dexmedetomidine and submitted to ovariohysterectomy

“…According to Groeben et al 17 , dexmedetomidine does not significantly decrease respiratory rate or spontaneous ventilation, differently from what was found in the present study and also reported by Gómez-Villamandos et al 18 in a study on the effects of the combination of propofol and desflurane in dogs pretreated with different doses of dexmedetomidine. The ventilation with oxygen-enriched air during the administration of 2 -agonists drugs greatly decreases the probability of hypoxia and cyanosis.…”

Sedative, analgesic, cardiopulmonary and haemodynamic effects of medetomidine-butorphanol and midazolam-butorphanol on thiopental-propofol anaesthesia in water buffaloes (Bubalus bubalis)

“…On comparison between P1 and P2 groups, no significant difference in SpO 2 was noted ( Figure 6). Propofol infusion has been reported to cause significant respiratory depression with decrease in all measures of ventilation in animals (Gomez-Villamandos et al 2006). It can be concluded that medetomidineÁ butorphanol combination produced better quality sedation and analgesia with quicker recovery and significantly more dose sparing effect on induction and maintenance agents accompanied with lesser cardiopulmonary depression than midazolam-butorphanol combination to thiopental-propofol anaesthesia in buffaloes.…”