Effect of artificial circadian rhythm of melatonin on sleep quality in patlents undergoing gynecological operation

Abstract

Objective To investigate the effects of artificial circadian rhythm of melatonin on the sleep quality in patients undergoing gynecological operation.Methods Eighteen ASA Ⅰ or Ⅱ patients,aged 25-50 yr,weighiug 45-80 kg,undergoing elective gynecological operation,were randomly divided into 3 groups ( n =6 each):blank control group (group C),placebo control group (group P) and melatonin group (group M).In group M,melatonin 6 mg was given orally at 10 min before lights-out (21:00) on 1 day before operation,on the day of operation and on 1 day after operation.While placebo was given orally instead of melatonin in group P.The operation was performed under epidural anesthesia.Patient-controlled epidural analgesia with ropivacaine was used for postoperative analgesia.Urine samples were collected at 6:00,10:00,14:00,16:00,18:00,20:00,22:00,0:00 and 3:00 on the day of operation and on 1 day after operation for determination of the melatonin concentration.Polysomnogram was monitored from 21:00 on 1 day before operation,on the day of operation and on 1 day after operation to 6:00 the next morning.The total sleep time,sleep latency,sleep time spent in stages Ⅰ -Ⅳ,rapid eye movement sleep time,slow wave sleep time and number of awaking were calculated.Sleep quality score during the nighttime was recorded on 1 day before operation,on the day of operation and on 1 day after operation.Results Compared with groups C and P,the melatonin concentration was significantly increased at 0:00,3:00 and 6:00 on the day of operation and on 1 day after operation,the total sleep time and sleep time spent in stage Ⅰ were significantly prolonged on the day of operation,and the sleep quality scorc during the nighttime was significantly increased on the day of operation and on Ⅰ day after operation in group M ( P ＜ 0.05 ).Conclusion Artificial circadian rhythm of melatonin can improve the sleep quality in patients undergoing g yneeological operation. Key words: Melatonin; Sleep; Gynecologic surgical procedures