Evaluation of an anaesthetic technique used in dogs undergoing craniectomy for tumour resection

Abstract

Objective To evaluate a total intravenous anaesthetic technique in dogs undergoing craniectomy.

Study design Prospective clinical study.

Animals Ten dogs admitted for elective surgical resection of rostro-tentorial tumours.

Methods All dogs were premedicated with methadone, 0.2 mg kg⁻¹ intramuscularly 30 minutes prior to induction of anaesthesia. Anaesthesia was induced with propofol administered intravenously (IV) to effect, following administration of lidocaine 1 mg kg⁻¹ IV and maintained with a continuous infusion of propofol at ≤0.4 mg kg⁻¹ minute⁻¹ during instrumentation and preparation and during movement of the animals to recovery. During surgery, anaesthesia was maintained using a continuous infusion of propofol at ≤0.4 mg kg⁻¹ minute⁻¹ and alfentanil ≤1 μg kg⁻¹ minute⁻¹. Lidocaine was administered at 1 mg kg⁻¹ IV immediately prior to extubation. Arterial blood pressure and heart rate (HR) were recorded prior to induction and every 5 minutes throughout preparation and surgery. Central venous pressure was recorded every 5 minutes throughout surgery.

Results Administration of propofol and lidocaine prevented significant increases in mean arterial blood pressure (MAP) and HR during endotracheal intubation and extubation. Adequate MAP was maintained throughout anaesthesia. Recovery was smooth and excitement free. There was no association between duration of anaesthesia, total drugs administered, or severity of neurological disease and recovery times. Postoperatively there was no deterioration in neurological function in the immediate postoperative period with complete resolution of pre-existing neurological deficits within 7 days of surgery.

Conclusion This technique provided minimal response to intubation and extubation, adequate arterial blood pressure and a smooth predictable recovery. All animals were neurologically improved by the time of discharge, suggesting that this technique had not caused significant neuronal damage.

Clinical relevance Total intravenous anaesthesia with propofol and alfentanil appears to be a satisfactory anaesthetic technique for use in dogs undergoing surgery for debulking/removal of rostro-tentorial tumours.