The Effect of Intraoperative Use of Dexmedetomidine During the Daytime Operation vs the Nighttime Operation on Postoperative Sleep Quality and Pain Under General Anesthesia

General anesthesia is a medically induced state of low reactivity consciousness which is similar to natural sleep. Some studies found that general anesthesia as an independent risk factor could result in a desynchronization of the circadian time structure and cause postoperative sleep disorders characterized by reduced rapid eye movement (REM) and slow wave sleep (SWS), which have significant deleterious impacts on postoperative outcomes, such as postoperative fatigue, severe anxiety and depression, emotional detachment and delirium, and even pain sensitivity or postoperative pain of patients.Clinical trials have already proved that intraoperative use of dexmedetomidine (DEX) for general anesthesia, a highly selective alpha-2 adrenergic agonist, was able to improve sedative and analgesia effects and promote sleep quality (by decreasing stage N1 sleep, increasing stage N2 sleep and sleep efficiency). However, Wenfei Tan et al reported that with the deeper sedative state provided by DEX in the daytime, the elderly male patients undergoing TURP under spinal anesthesia suffered worse sleep on the night of surgery. Thus, what the effect of intraoperative using DEX at different time periods under general anesthesia on postoperative sleep quality and pain will be needs further study.