A randomized and prospective study was performed to compare anaesthetic characteristics and stress hormone responses of two anaesthetic techniques.

Forty-two patients undergoing day case excisional biopsy of breast mass were randomly assigned to receive propofol–remifentanil or sevoflurane–N2O. Anaesthesia was induced and maintained either with sevoflurane and 50% N2O in oxygen or with target-controlled remifentanil and propofol in 50% oxygen and air. Anaesthetic depth was monitored by the bispectral index.

The times for induction (2.9 vs. 1.7 min) and for laryngeal mask insertion (5.7 vs. 3.3 min) were longer in the sevoflurane–N2O group than in the propofol–remifentanil group. However, apnoea (57.1% vs. 9.5%) and bradycardia (23.8% vs. 0%) were more prevalent with propofol–remifentanil. In the sevoflurane–N2O group, the emergence times to a verbal response (10.6 vs. 3.7 min), to extubation (11.8 vs. 4.0 min) and to orientation (14.7 vs. 4.8 min) were longer than in the propofol–remifentanil group. There were significantly more nausea (38.1% vs. 4.8%) and vomiting (19.2% vs. 0%) in the sevoflurane–N2O group than in the propofol–remifentanil group. The time to discharge was similar although there was less postoperative pain in the sevoflurane–N2O group. There were no differences in the perioperative cortisol responses in the two groups.

Smoother induction of anaesthesia was seen with sevoflurane–N2O. Propofol–remifentanil showed a quicker emergence with less nausea/vomiting. There were similar perioperative cortisol responses in the two anaesthetic techniques.