Target-controlled infusion of propofol combined with variable rate infusion of remifentanil for anaesthesia of a dog with patent ductus arteriosus

An 18-month-old Lurcher was anaesthetized for surgical ligation of a patent ductus arteriosus using a target-controlled infusion (TCI) of propofol and a variable rate infusion of remifentanil. Before anaesthesia, radiographic and echocardiographic examination indicated that the dog had left-sided congestive heart failure and impaired left ventricular systolic function. Ramipril and furosemide were administered pre-operatively. Following pre-anaesthetic medication with morphine, 0.5 mg kg−1, by intramuscular injection, and pre-oxygenation, remifentanil was infused for 5 minutes at 0.2 μg kg−1 minute−1, followed by induction of anaesthesia using intravenous propofol administered by TCI, set at a target concentration of 3.5 μg mL−1 of propofol in blood. Tracheal intubation was performed and 100% oxygen delivered through a non-rebreathing (Bain) system and then a circle system in the operating theatre. Anaesthesia was maintained with propofol and remifentanil, adjusted according to clinical requirements. Peri-operative analgesia consisted of intercostal bupivacaine nerve block, with meloxicam, morphine and remifentanil.