Comparison of Morning and Evening Operation Under General Anesthesia on Intraoperative Anesthetic Requirement, Postoperative Sleep Quality, and Pain: A Randomized Controlled Trial

OBJECTIVE: Postoperative sleep disorders can cause serious adverse effects on postoperative outcomes. The purpose of our study was to compare the effects of the timing of surgery under general anesthesia on intraoperative anesthetic drug requirements, postoperative sleep quality and pain in patients. MATERIALS AND METHODS: Eighty-four patients who underwent selective laparoscopic abdominal surgeries under general anesthesia were randomly assigned to the Day Group (8:00–12:00) or the Night Group (18:00–22:00). The portable sleep monitor (PSM) was used to determine sleep quality on the night before surgery (Sleep-preop), the first night after surgery (Sleep POD 1), and the third night after surgery (Sleep POD 3). The visual analog scale (VAS) was used to evaluate postoperative pain scores and the Athens Insomnia Scale (AIS) was used for assessing insomnia symptoms. The total dose of general anesthetics required and adverse effects after surgery were also assessed. RESULTS: Compared to Sleep-preop, patients presented with a lower sleep efficiency and a higher AIS score during Sleep POD 1 and Sleep POD 3. Furthermore, the Night Group had a significantly lower proportion of rapid eye movement sleep, stable sleep, and unstable sleep than did the Day Group at Sleep POD 1 and Sleep POD 3. The dosage of propofol and remifentanil required in the Day Group was significantly higher than that in the Night Group. Furthermore, patients in the Day Group had better pain relief, with a lower VAS score at 1, 6, 12, and 24 hours after surgery. The incidences of postoperative nausea and vomiting and dizziness were significantly higher in the Night Group than those in the Day Group. CONCLUSION: Morning operations required a higher dose of anesthetic drugs than did evening operations, which may be related to the circadian rhythm. The degree of postoperative sleep disorders was greater when the operation was performed in the evening than in the morning, which was also associated with increased pain perception and increased incidence of postoperative adverse effects. Thus, our results suggest that patients with hyperalgesia and sleep disorders may benefit from operations performed in the morning.