Patients having surgery for breast cancer receive a paravertebral blockade at C8-Th4 with either Naropin 0.5% or saline. General anaesthesia is then provided with laryngeal mask intubation, propofol infusion and fentanyl i.v. as needed. The effect on postoperative pain ([VAS] and fentanyl PCA doses taken) and postoperative nausea and vomiting is recorded.