Study design

Inclusion criteria for the subjects were age more than 18 years old with elective open or laparoscopic hysterectomy for benign conditions. Exclusion criteria were genital prolapse as indication for the hysterectomy, previous bilateral oophorectomy or the present operation would leave the woman without ovaries, physically or mentally disabled, severe psychiatric disease, or informed consent could not be obtained. All hysterectomies were total, but the type of surgical procedure was up to the operating surgeon. The criteria for laparoscopy or laparotomy were based on the Clinical guidelines for treatment [16, 17]. To avoid the influence of radiotherapy or chemotherapy on patients experience and outcomes, patients with malignant and borderline tumors were excluded. Six surgeons, twelve nurses, five anaesthetists, one dieticians, and three physiotherapists formed the ERAS multi-disciplinary team (MDT), which effectively implemented the ERAS protocols. The protocols are based on the practice guidelines for gynecologic surgery by the ERAS society [16–18] and consist of 22 items involving preoperative, intraoperative and postoperative interventions (Additional file 1). All treatments were performed by ERAS MDT. To ensure that the protocols were running smoothly, everyone on the team communicated with each other and reported their work at weekly meetings. The study protocol conforms to GCP (Good Clinical Practice) standard procedures, and all investigators were trained and certified.

The Department of Gynecology of the First Affiliated Hospital of Chongqing Medical University serves a large geographic area in western and southwestern China with a referral base of 2 million people. The first gynecological oncology guidelines recommended by the ERAS Society were published in 2016 [18, 19] and revised in 2019 [20], which was formally carried out in our hospital from October in 2016. Every patients would receive a “rehabilitation log” which containing perioperative ERAS guidelines and survey on each items. Periodic text message reminders were sent to remind participants about completion of the rehabilitation logs every day, such as early mobilization and early oral intake. For example, on the first postoperative day, in addition to the pre-operative education by nurses, mobile phone messages would remind patients that they should have an out-of-bed activity for 2 h.

The implementation of each item for each patient and outcome were collected prospectively. For categorical elements compliance was marked as yes/no. For intravenous fluids on the first postoperative day, ERAS compliance with balanced fluids was set to less than 2000 ml. The compliance rate for each patient was calculated as the number of interventions fulfilled/22 (total number of ERAS items). Mean total compliance was calculated as the average of all perioperative ERAS interventions. Patients were categorized into three groups by their compliance rates with the ERAS pathway. The same cut-off values as previous studies were used, [21, 22] where compliance was classified as ‘poor’, ‘partial’, or ‘full’ when < 50%, ≥50%, or ≥ 80%. However, in the pilot trial before the formal start of this study, only a very small number of patients had a compliance rate < 50%, so the poor group was classified as < 60%. Each patient was followed by the ERAS team members during the hospital stay.

Characteristics of the study population, age, body mass index (BMI), education level, smoking status, nutritional risk screening (NRS) score, NYHA status, ASA status, history of surgery, preoperative hemoglobin, presence of chronic pain, history of postoperative nausea and vomiting (PONV), diagnosis and type of surgical procedure were recorded. Preoperative comorbidities were also recorded, such as hypertension, diabetes, chronic obstructive pulmonary disease (COPD), ischemic heart disease and asthma. After entering the operating room, the plasma electrolyte level was monitored by invasive arterial pressure puncture. Preoperative hypokalemia was defined as less than 3.5 mmol/L. Intraoperative data were prospectively collected, including duration of surgery (min), intraoperative net fluid input and blood loss.

All of the patients were asked to complete 15-item quality of recovery (QoR-15) questionnaire, a widely used self-rated questionnaire for early postoperative quality of recovery [23, 24] (Additional file 2), under the guidance of the investigator on the day before operation, then to repeat it 24 h/48 h/72 h postoperatively [25]. QoR-15 is a patient-centered comprehensive questionnaire (15-items), which includes five aspects: physical comfort (5-items), emotional status (4-items), physical independence (2-items), psychological support (2-items) and pain (2-items) [26]. Total scores of the QoR-15 ranges from 0 to 150, higher score indicates better recovery. At the same time, their resting pain was also measured with an 11-pointed visual analogue scale (VAS) ranging from 0 to 10, with 0 indicating no pain and 10 indicating the worst pain imaginable. VAS ≥ 4 was considered to identify patients with postoperative pain of moderate-to-severe intensity. The Likert scale (strongly dissatisfied = 1, moderately dissatisfied = 2, slightly dissatisfied = 3, neutral = 4, slightly satisfied = 5, moderately satisfied = 6, extremely satisfied = 7) was used to evaluate patient satisfaction on the day of discharge and 30 days after discharge [27]. On this instrument, a higher score indicates a higher level of satisfaction.

Patients were discharged when they met the strict criteria: mobilization with normal diet, oral analgesics for pain relief, normal urination and no intestinal obstruction signs. Patients were contacted by a dedicated nurse on the telephone at 30 days after discharge. The readmission, postoperative chronic complications and patient satisfaction were also collected.