Effect of penehyclidine hydrochloride on the incidence of intra‐operative awareness in Chinese patients undergoing breast cancer surgery during general anaesthesia

Summary Intra‐operative awareness can lead to serious adverse psychological consequences. We conducted a prospective, randomised, double‐blinded trial in 920 patients undergoing breast cancer surgery under bispectral index‐guided total intravenous anaesthesia to evaluate the effect of penehyclidine hydrochloride on intra‐operative awareness. Patients were randomly divided to receive 0.01 mg.kg−1 penehyclidine hydrochloride or saline intravenously 30 min before surgery. The pre‐administration, pre‐operative anxiety levels were assessed using a 100‐mm visual analogue scale. Intra‐operative awareness was defined as recall of intra‐operative events using a modified Brice interview administered 2–6 h postoperatively, and in the next 24–48 h. A committee of three experts, blinded to the study conditions, independently scrutinised all reported recollections. We found no differences in depth of anaesthesia and patients' pre‐operative anxiety levels between the two groups. The incidence of awareness with penehyclidine hydrochloride (0/456 patients; 0%) was significantly lower than with saline (5/452; 1.1%), p = 0.030. We conclude that penehyclidine hydrochloride reduced the incidence of intra‐operative awareness in patients undergoing breast cancer surgery during general anaesthesia.