Clinical evaluation of a new formulation of propofol in a medium-chain and long-chain triglycerides emulsion in dogs.

Propofol formulated in a mixed medium-chain and long-chain triglycerides emulsion has been recently introduced for clinical use as an alternative to the conventional long-chain triglycerides formulation. This prospective multicentric study evaluated the clinical effectiveness and the complications associated with the use of this new formulation of propofol in dogs. Forty-six Spanish veterinary clinics participated in this study. A total of 541 anaesthesias (118 ASA I, 290 ASA II, 101 ASA III and 32 ASA IV) performed for various diagnostic and therapeutic purposes were evaluated. The anaesthetic protocol was not controlled, with the exception that propofol had to be used at least for induction of anaesthesia. The induction dose of propofol and the incidence of anaesthetic complications throughout the procedure were recorded. A chi-square test compared the incidence of complications according to the maintenance agent used (propofol vs. inhalatory anaesthesia), anaesthetic risk (ASA classification) and the reason for the anaesthesia. The patients premedicated with alpha2 agonists needed lower doses (mean +/- SD, 2.9 +/- 1.3 mg/kg i.v.) than the animals premedicated with phenothiazines (3.9 +/- 1.4 mg/kg i.v.) or benzodiazepines (4.0 +/- 1.4 mg/kg i.v.). The most frequent complications were difficult endotracheal intubation (1.3%), postinduction apnoea (11.3%), cyanosis (0.6%), bradypnoea (2.6%), tachypnoea (2.8%), bradycardia (2%), tachycardia (2.6%), hypotension (0.2%), shock (0.2%), vomiting (4.6%), epileptiform seizures (2.8%), premature awakening (7.4%) and delayed recovery (0.9%). There were no cases of pain on injection or aspiration pneumonia. Three dogs died (0.55%), one during induction and two during recovery from anaesthesia. This study demonstrates that the new formulation of propofol is an useful and effective drug to induce general anaesthesia in dogs.