Propofol and sufentanil may affect the patients’ sleep quality independently of the surgical stress response: a prospective nonrandomized controlled trial in 1033 patients’ undergone diagnostic upper gastrointestinal endoscopy

The study was approved by the institutional ethics committee of West China Hospital Sichuan University (Chengdu, China) and registered on Chinese Clinical Trial Registry (ID ChiCTR-OCH-13003128). Written informed consent about the study protocol was obtained from each patient preoperatively. Patients who decided diagnostic UGE under sedative were allocated to the sedative group, while other patients allocated to the routine group (without sedative). One thousand and thirty-three patients, ≥18 years, American Society of Anaesthesiologists (ASA) physical status classification I–II, undergoing outpatient diagnostic UGE were enrolled to the study (Fig. 1). Exclusion criteria included known sleep disorders, use of sedatives or hypnotics, alcohol abuse (more than 35 units per week), expected compliance problems (known psychiatric disease, difficulty in reading or speaking in Chinese) or undergoing sedative (general or local) or surgery during the 1 month follow-up period.

Standard monitoring including electrocardiograph (ECG), pulse oximeter (SPO₂), and noninvasive blood pressure (BP) were applied. Two minutes before endoscopy, patients were pre-oxygenated (Fraction of inspiration O2, FiO₂ = 1.0) by face mask and oxygen was delivered (FiO₂ = 0.33) for the following procedure. For the sedative group, anaesthetic management was standardized. After pre-oxygenation, sedative was administered with sufentanil 3-5 μg over 5 to 10 s and propofol (1% Diprivan™; AstraZeneca Japan, Osaka, Japan) 1.0 mg · kg^–1intravenously. Supplemental doses of 0.5 mg/kg propofol were administered when the patient was conscious or body movement was found [17]. In contrast, no anaesthetics were administered to the patients in the routine group and the patients maintained conscious throughout the procedure. The diagnostic UGE was performed with a video endoscope by the experience gastroenterologist. Atropine (0.005-0.01 mg/kg) or ephedrine (0.1-0.2 mg/kg) would be respectively administered IV, when HR was less than 60 bpm or systolic blood pressure was less than 80 mmHg or 80% of its baseline. Patients who achieve Modified Post anaesthesia Discharge Scoring System (PADSS) score of 9 or more were considered to be ready for discharge [18].

The sleep quality was assessed using the 19-item PSQI (Pittsburgh Sleep Quality Index) questionnaire (Additional files 1 and 2) [8, 9]). The PSQI have 7 components including sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, daytime dysfunction, and use of sleeping medications which range 0–3, respectively. The global PSQI score ranging from 0 to 21 is generated by summing up 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.

All patients were required to evaluate their sleep quality as the baseline when they make an appointment on the Endoscopy Center of West China Hospital 3-5 days before the diagnostic UGE. At the time of the follow-up visit (1 week and 1 month after procedure), all patients were asked to assess their sleep quality via telephone by an investigator who was blinded to the assigned groups.

Based on our pilot study data from our 150 patients, the mean PSQI scores were 5.24 for the sedative group and 4.82 for the routine group with a standard deviation (SD) of 2.11. A sample size of 796 (398 in each group) allowed the detection of a 20% difference between the two group, with an α of 0.05 (two tailed) and a β of 0.20, power of 0.8. To account for 20% attrition, a sample size of 956 (478 in each group) was selected.

Data was analyzed with SPSS Version 13.0 (SPSS Inc., Chicago, IL). Mann-Whitney U test or χ ² test was used to compare the two groups with respect to the background characteristics such as age, sex, ASA and baseline PSQI scores. Linear mixed model was used to evaluate the PSQI score differences between the two groups and changes after post-endoscopy time. Bonferroni correction was made when necessary to correct for multiple test. P < 0.05 was considered statistically significant.