Anaesthesia may be maintained using halothane in oxygen by inhalation. Should maintenance of surgical anaesthesia be required when facilities for gaseous anaesthesia are not available, this can be achieved by ‘topping up’ doses of romifidine/ketamine or thiopentone.

To maintain or deepen surgical anaesthesia with romifidine/ketamine, administer the product intravenously at a dose of 0.25ml/100 kg bodyweight (25 micrograms/kg romifidine) followed immediately by ketamine intravenously at a dose of 1.1mg/kg (Vetalar 1.1ml/100 kg). Administer the romifidine/ketamine top-up dose immediately prior to commencement of surgical incision or when signs of returning consciousness appear.

Thiopentone may be used after romifidine/ketamine or romifidine/thiopentone induction at a dose of 0.25g/100 kg bodyweight. This should be administered when signs of returning consciousness appear. This can be repeated up to 3 times after the induction dose.