The Impact of Morning Surgery or Afternoon Surgery on Postoperative Sleep Quality and Melatonin Levels of Elderly Patients: A Prospective, Randomized Study

Abstract

Objective

Postoperative sleep disturbance after surgery is not conducive to the recovery of patients. The purpose of this study was to determine the influence of the timing of surgery (morning vs afternoon) on the postoperative sleep quality of elderly patients and to analyze the relationship between the timing of surgery and the change in the melatonin level.

Methods

Sixty patients who received hip surgery were randomly assigned to the Morning Group (Group M) or the Afternoon Group (Group A). The sleep quality was assessed by the Richards–Campbell Sleep Questionnaire. Before and after surgery, the nocturnal urine was collected over a 12-h period, and the 6-sulfatoxymelatonin concentration was measured. Also, the incidence of postoperative delirium (POD) was observed.

Results

On the first and second nights after surgery, the sleep quality scores of the patients in Group A were greater than those in Group M, and there was no difference in the sleep quality scores between the two groups on the third night after surgery (P=0.000, P=0.002, P>0.05, respectively). In addition, the urine 6-sulphatoxymelatonin concentration was found to be greater in Group A than in Group M on the first night of surgery (P=0.00). Both the postoperative sleep quality scores and urine 6-sulphatoxymelatonin concentration were significantly less than those before surgery (P=0.00, P=0.00).

Conclusion

The postoperative sleep quality scores and melatonin levels of elderly patients who received hip surgery under general anesthesia were significantly less than those of the patients before surgery. Furthermore, the short-term sleep quality of the patients who received surgery in the afternoon was better than that of the patients who received surgery in the morning. This difference may be related to the short-term change of the melatonin level after surgery.

Keywords:

• sleep quality
• melatonin
• timing of surgery

Registration

This work was registered at the Chinese Clinical Trial Register (ChiCTR2100046773).

Data Sharing Statement

Individual deidentified participant data can be obtained from the corresponding author with approval from the corresponding author within three years of publication, as can the published main results as well as the study protocol.

Ethical Adherence

Ethical approval (PJ2020-17-17) was provided by the Ethical Committee Anhui Medical University, Hefei, Anhui, China. All patients provided informed consent and all procedures were conducted according to the Declaration of Helsinki.

Acknowledgment

The authors would like to thank Panpan Fang, MD, Ph.D., from the Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China for her work on statistical analysis.

Disclosure

The authors report no conflicts of interest in relation to this work.

Additional information

Funding

This work was supported by the National Nature Science Foundation of China (Grant No. 82172136) and the Innovation and entrepreneurship project for returned overseas students in Anhui Province (Grant No. 2022LCX023).