Retraction Note: Effects of ultrasound-guided stellate-ganglion block on sleep and regional cerebral oxygen saturation in patients undergoing breast cancer surgery: a randomized, controlled, double-blinded trial

Numerous factors could contribute to sleep disturbances in women with breast cancer. We hypothesized that stellate ganglion block (SGB) during surgery would preserve sleep after surgery and increase intraoperative regional cerebral oxygen saturation (rSO 2 ) on the blocked side in patients undergoing breast cancer surgery. A randomized, double-blinded, controlled trial was conducted at the First Hospital of China Medical University from January 2016 to September 2016. Ninety-six patients who underwent radical breast cancer surgery requiring general anaesthesia were randomly assigned to one of two study groups: a control group that received a saline SGB and a block group that received a 0.25% ropivacaine hydrochloride SGB. The primary outcome measure was the postoperative sleep profile, which was assessed using the bispectral index on the first postoperative night. The secondary outcome measure was the intraoperative rSO 2 , monitored was throughout surgery using near-infrared spectroscopy. A total of 91 female patients (mean age: 45 years; range 24–51 years) were included in the study. The duration of sleep was significantly increased by 66.3 min in the ropivacaine-SGB group compared with the saline-SGB group. No differences in rSO 2 were observed on either the left or right side of the patients in either group 50 min after anaesthesia induction. We conclude that ropivacaine-SGB combined with general anaesthesia might increase the first postoperative sleep duration without influencing the intraoperative rSO 2 in female patients undergoing elective breast cancer surgery. Clinical trials.gov identifier NCT02651519