Participants
This study was conducted in the Department of Gastrointestinal and Pancreatic Surgery, First Affiliated Hospital of Sun Yat-sen University from November 2008 to January 2009. The surgical procedures were performed by experienced surgeons (they had performed at least 200 colorectal procedures before participating in the study). Seventy patients who were clinically diagnosed as having colorectal carcinoma were assigned randomly to two groups comprising 35 patients each: FTS group and conventional care group. Inclusion criteria included: age ≥18 and ≤80 years, no preoperative chemotherapy or radiotherapy, American Society of Anesthesiologists (ASA) grade I/II, body mass index (BMI) 17.5–27.5 kg/m2, preoperative serum albumin ≥30 g/l. All of the patients underwent elective open colorectal resection with combined tracheal intubation and general anesthesia. Exclusion criteria included immune-related disease; primary diabetes mellitus or impaired glucose tolerance; hiatus hernia; gastroesophageal reflux disease (GERD); pregnancy; bowel obstruction; patients with difficult airway access (difficult to intubate); and drug intake, which might affect bowel movement and function. Patients also would be excluded if the following circumstances occurred: failure of thoracic epidural catheter insertion; intraoperative blood transfusion; patients who required a stoma; unresectable carcinoma.
The study protocol was approved by the Research Ethics Committee of the First Affiliated Hospital of Sun Yat-sen University (Guangzhou, China). Written informed consents were obtained from the patients and their families. This study was registered under chictr.org, identifier number ChiCTR-TRC-00000157.
Interventions
The intervention protocols of the FTS group were as follows: normal meal until 10 p.m. the day before surgery; drink 250 ml of 5 % carbohydrate 2 h before surgery [8]; no routine nasogastric tube drainage; early as possible removal of urine and venous catheters (urinary catheter: removed when the patient became conscious and could be mobilized out of bed; deep venous catheter: removed when vital signs were stable); oral feeding started 6–12 h after surgery, following a stepwise plan from oral liquid nutrition to normal diet. Ensure (400 g; Abbott, Chicago, IL, USA) was applied as oral nutrition and was mixed with water for 1 Kcal/ml. The oral feeding plan was as follows: 6–12 h after surgery, Ensure mixture, 30–50 ml every 1–2 h; postoperative day (POD) 2 and afterward, Ensure mixture, 100–200 ml every 2–3 h, plus semi-fluids according to the patient’s tolerance. Mobilization was encouraged from the night of the operation. Patients were encouraged to meet predefined mobility targets over the postoperative days.
The intervention protocols of the conventional group were as follows: normal meal until 10 p.m. the day before surgery, routine use of nasogastric tube drainage, and oral intake initiated on return to normal gastrointestinal function (bowel sounds or flatus) following a stepwise plan from oral liquid nutrition (Ensure 400 g) to a normal diet. Patients were sat up and assisted to mobilize on POD 1, but they were not aggressively mobilized until discontinuation of the thoracic epidural. Urinary catheters were removed following epidural catheter removal.
The same interventions were applied in both groups: Routine bowel preparation was done with gentamicin and metronidazole. Polyethylene glycol electrolyte powder (HYGECON, Jiangxi, China) was used as a laxative. Other measures included prophylactic use of antibiotics; avoidance of long-acting opioids; intraoperative maintenance of normothermia with an upper-body forced-air heating cover; a midline incision of minimal length; intraoperative and postoperative fluid restriction; no routine use of abdominal drains; the combination of continuous epidural mid-thoracic local anesthetics plus nonsteroidal antiinflammatory drugs (NSAIDs) to control postoperative pain. Postoperative blood glucose was controlled with the fasting blood glucose (FBG) level maintained at <12 mmol/l. Administration of any blood product was unacceptable, as was giving any agent that could affect immunity. Total postoperative calorie administration was controlled in the range of 25–30 Kcal/kg per 24 h in both groups.
Discharge criteria included the following: normal body temperature; independently mobile; return to normal gastrointestinal function (defecation at least once); normal oral diet, no need for parenteral nutrition; controllable pain with oral analgesia; willing to go home. Patients were readmitted at the request of the primary care physician or if the patient made direct contact with the hospital describing deteriorating health at home. Patients were followed up within 1 month after discharge (follow-up by telephone every 3 days during the first 2 weeks, once a week during the last 2 weeks). The patient was told that the researcher should be informed promptly if the patient had any discomfort.
Both groups were protocol-driven, with checklists for patients, nursing staff, and surgical staff to help maintain compliance. Teaching sessions and dummy runs were held before trial commencement to clarify potential points of confusion and reduce protocol violations. Patients were admitted to one of two nursing areas depending on the results of randomization. Although the interventions were protocol-driven, a geographically separate location was considered desirable to minimize protocol contamination.
Measurements
Patients’ preoperative self-feelings were evaluated before anesthesia induction (e.g., thirsty, hungry). Anesthesia-related complications were measured. Intraoperative measurements were carefully recorded in detail, including surgical procedures, blood loss, fluid transfusion, and blood transfusion, among others. The return of normal gastrointestinal function (time to first bowel sounds/flatus, defecation, initiation of soft diet), hospital stay, and complications were recorded postoperatively. Blood tests [white blood cell (WBC) count, liver function tests (LFTs), serum biochemistry, humoral immunologic index] were performed on appointed days. The humoral immunologic factors tested in our study included serum globulin, immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin A (IgA), complement 3 (C3), and complement 4 (C4).
Experimental blood tests were performed on the morning of the operation and on PODs 1, 3, and 7. All blood samples were taken from peripheral veins at 6 a.m., before breakfast. We also took blood samples to test the WBC count at the end of surgery.
Sample size, randomization, and implementation
The intention of our study was to detect possible changes of human immunity on the basis of clinical benefits. Like many other clinical studies, we selected the length of hospital stay (LOS) as the main endpoint. On the basis of previous data for postoperative LOS, (10.38 days on average) for patients undergoing major colonic surgery at our institution, we calculated that 35 patients in each group would be required to detect a 30 % reduction in postoperative LOS with an α level of 0.05 and a β level of 0.01.
Patients were informed about the aims and details of this study. Patients signed consent forms after the study was explained. Block randomization was computer-generated. Eligible patients were randomly assigned in a 1:1 ratio. The investigators who designed the study prepared the envelopes and assigned participants to their groups but had no contact with the patients throughout the study. The investigator recruiting the patients, administering the interventions, and evaluating the outcomes had no role in the randomization process.
Statistical analyses
Data were analyzed using SPSS for Windows 13.0 (SPSS, Chicago, IL, USA). Numerical variables were expressed as the mean ± SD unless otherwise stated. Categoric variables were expressed by a constituent ratio or rate. Differences between the two groups were tested using a two-tailed Student’s t test for normally distributed data and the Wilcoxon test for noncontinuous variables. The χ2 test and Fisher’s exact test were used to compare discrete variables. A value of p < 0.05 was considered statistically significant.
Compared with our primary protocol, we made a modification to the enrollment of participants before trial commencement, which initially intended to enroll patients with gastrointestinal tumors other than colorectal cancer. The aim was to control the homogeneity of the patients and thus control bias. The sample size decreased from 60 to 35 accordingly. The Research Ethics Committee of the First Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) approved all the changes.