A Comparison of the Effects of Prolonged Infusion of Propofol 2% and 1% During Total Intravenous Anaesthesia Using Target-Controlled Infusion Technique for Elective Neurosurgery

BACKGROUND: Total intravenous anaesthesia (TIVA) with a combination of target-controlled infusions (TCIs) of propofol and remifentanil has been advocated for a favourable neurosurgical outcome. Neurosurgical procedures often involve a prolonged duration and large cumulative infusion of propofol. This study compares the serial serum lipid profile, acid-base balance and lactate level of neurosurgical patients anaesthetised with TCIs of propofol at 2% versus 1%. METHODS: A total of 74 patients who underwent an elective craniotomy under general anaesthesia were randomised into two groups: i) propofol 1% (n = 37) and ii) propofol 2% (n = 37). All patients were anaesthetised using TCIs of propofol and remifentanil. Serial lipid profiles (serum triglyceride [TG] and cholesterol levels) were taken at the baseline, upon cessation of propofol and at 2 h post-operation. The total dosage, volume used and syringe changes of both groups were also documented. RESULTS: The total volume of propofol used was significantly lower in the 2% group than the 1% group (157.19 mL [SD = 77.14] versus 335.17 mL [SD = 174.27]; P = 0.005) and the frequency of syringe changes was also less in the 2% than the 1% group (2 [3] versus 6 [3]; P < 0.001). However, there were no significant differences between the two groups in terms of serial serum TG, cholesterol, the acid-base balance or the lactate level. There was also no significant correlation of lipid profile with cumulative dose or volume of propofol infused between the two groups. CONCLUSION: Both concentrations of propofol, 1% and 2%, were comparable in terms of the serial lipid profile, acid-base balance and lactate level during TIVA using TCIs for elective neurosurgery. The benefits of propofol at 2% were that a lower volume was used and there were fewer syringe changes, which could minimise anaesthesia interruption throughout surgery.