Liuboshevskii 2012.

Methods	RCT Setting: Russia Funding: unspecified
Participants	120 patients scheduled to undergo elective gastrointestinal low‐abdominal surgery Patients with coagulation/haemostasis abnormalities including liver failure were excluded
Interventions	Treatment group: TEA (T8) with 0.75% ropivacaine for surgery followed by ropivacaine 0.2% plus fentanyl 2 mcg/mL 6 to 10 mL/h and systemic ketorolac administration (n = 40). Exact duration not specified Control group: IM trimeperidine 20 mg every 4 to 6 hours and ketorolac 30 mg every 8 hours (n = 40) All participants had total intravenous anaesthesia based on propofol, fentanyl and mechanical ventilation
Outcomes	VAS scores at 6, 24 and 48 hours
Notes	Study includes a third group with general anaesthesia plus spinal anaesthesia not included in the analysis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"divided", 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	No loss to follow‐up
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Low risk	Groups well balanced