Zhu 2013.

Methods	RCT Approved by the ethics committees and written informed consent obtained for all patients Setting: China Funding: unspecified
Participants	67 patients undergoing D2 (systematic dissection of lymph nodes in the second tier with clear histological margins.) radical gastrectomy for gastric cancer
Interventions	Treatment group: TEA (T8‐T9) PCEA with bupivacaine 0.05% and morphine 0.1 mg/mL for 48 hours (n = 34) Control group: IV PCA with morphine (n = 33) General anaesthesia for all participants; pethidine was used as a supplemental drug for breakthrough pain in both groups
Outcomes	Time to first flatus (hours) VAS at rest at 24 and 48 hours VAS on movement (coughing) at 24 and 48 hours Anastomotic leak Hospital LOS (Predetermined discharge criteria were used to measure length of hospital stay after the operation. Criteria were defined as eating a normal diet, tolerating clear fluids for 24 hours, having no complaints of pain, providing no evidence of complications for 24 hours and obtaining consent from the participant)
Notes	Study authors contacted for additional information on 13 July 2014, but did not reply
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"randomly assigned", no details
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not mentioned
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not mentioned
Incomplete outcome data (attrition bias) All outcomes	Low risk	7 participants excluded from analysis
Selective reporting (reporting bias)	Low risk	All results provided
Other bias	Unclear risk	Groups well balanced Not in intention‐to‐treat