Clinical comparison of the effects of isoflurane or propofol anaesthesia on mean arterial blood pressure and ventilation in dogs undergoing orthopaedic surgery receiving epidural anaesthesia

Anaesthetic maintenance in groups I and P was accomplished by providing a mean EtISO of 1.12 ± 0.15% and a mean propofol infusion rate of 15.0 ± 4.7 mg/kg/h, respectively. MAP was significantly higher in group P than in group I (92 ± 17 mmHg versus 78 ± 10 mmHg; P = 0.021). Eleven dogs in group P and two dogs in group I reached an EtCO2 > 7.3 kPa, requiring mechanical ventilation (P = 0.001). In combination with epidural anaesthesia, propofol TIVA improved MAP and is a suitable alternative to isoflurane in orthopaedic surgery of the hind limb in healthy dogs. Nevertheless, since it was associated with increased respiratory depression, mechanical ventilation should be available.