A healthy sleep cycle and the sleep pattern is necessary for maintaining normal physiological and mental functions of the body. Earlier studies have reported the complaints of sleep disturbances in postoperative patients.  The main factors that may influence the postoperative sleep include surgical stress response, sedatives and postoperative pain. However, there is a lack of evidence about the independent effect of sedatives on postoperative sleep disturbances. Diagnostic UGE is a minimal invasive procedure performed with or without a sedative. Propofol, opioids or imidazole are commonly used sedatives to facilitate patients' tolerance.  Diagnostic UGE is not expected to cause tissue trauma, and patients rarely complain of pain after this procedure. These factors offer significant advantages to researchers to predict whether sedative independently can become a cause of the postoperative sleep disturbance without the confounding effects of surgical stress response and postoperative pain. The Pittsburgh Sleep Quality Index (PSQI) has been established as an essential tool for the assessment of the quality of sleep. It exhibits a higher degree of internal homogeneity, overall consistency and clinical validity than any other test available. The reporting period of PSQI is 1 month, but the PSQI questionnaire was used for short-term evaluation for 1 week in this study. Various previous studies had been conducted that investigates the short-term sleep quality using PSQI.

Rationale behind the research:

• Previous studies have majorly discussed the combined effect of the surgical stress response, sedatives and postoperative pain on sleep disturbances
• Thus, the present study was done to evaluate the independent effect of sedatives on the postoperative sleep disturbances without the confounding effects of surgical stress response and postoperative pain

Objective:

To confirm the sleep quality of patients undergoing routine (without sedative) diagnostic UGE or UGE with a sedative, before, 1 week, and 1 month after the procedure.

Study outcome measures

• Sleep Quality: The sleep quality was measured by the 19-item PSQI questionnaire. The PSQI has 7 components: sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, daytime dysfunction, and use of sleeping medications. The global PSQI score varies from 0 to 21 which is formed by adding all the seven component scores, where 0 indicates no difficulty and 21 is severe difficulty in all areas. A global cut-off score of PSQI greater than 5 is used to distinguish poor sleepers from good sleepers.

Time Points: Baseline, 1 week and 1 month after the procedure

Study outcomes

• Baseline: No significant baseline differences were observed between the sedative and routine group. 
• Patients in the sedative group showed significantly higher PSQI scores (worse sleep quality) than the baseline PSQI scores (p < 0.001) after one week of the procedure. No significant change was observed for the routine group in the same period (p = 0.096).
• Also, there was no significant difference in PSQI scores between the two groups compared with the baseline values (p = 0.358 for sedative group, p = 0.161 for routine group)  after one month of the procedure.

Fig 1: Changes in PSQI scores from baseline to 1 week and 1 month after the procedure in sedative and routine groups

The present study showed that the patients undergoing sedative diagnostic UGE had impaired sleep quality as compared to baseline one week after the procedure. It was the first study that evaluated the individual effects of sedatives on sleep quality of patients that has undergone diagnostic UGE.

Many studies have shown similar outcomes about disturbed postoperative sleep quality. In a recent survey by Yilmaz et al., the sleep quality and its parameters were investigated in patients undergoing coronary artery bypass grafting (CABG) surgery in comparison to the healthy patients. The results showed that there were disturbances in sleep quality and parameters, one week after the surgery as compared to healthy individuals. Sleep quality was found to be severely impaired in CABG patients. However, the quality of sleep returned to the preoperative baseline values 1 month after CABG, so did the diagnostic UGE.

Various factors contribute to the postoperative sleep disturbances including the injury of surgery followed by a complex stress response, the magnitude of the surgical procedure, postoperative pain and psychological factors (anxiety and negative mood states). Among these, the effect of physiological factors on sleep quality was found comparable in both sedative and routine group.

The independent effect of sedative or anesthetics on postoperative sleep disturbance in the diagnostic UGE patients was confirmed. Recently, Propofol has shown to change the sleep architecture significantly with the increase in N3 sleep (deep or delta-wave sleep) and total abolishment of rapid-eye-movement (REM) in healthy humans. Pieces of evidence also suggest that opioids use like morphine can alter sleep architecture with the increase of N2 (stage 2 of sleep) and reduction of slow wave sleep (SWS) in healthy humans. The possible reason behind impaired sleep quality 1 week after diagnostic UGE was thought to be the reduction in REM and SWS.