Bellolio 2012.

Methods	RCT Informed consent obtained Setting: Uruguay Funding: unspecified
Participants	21 patients undergoing liver surgery
Interventions	Treatment group: epidural local anaesthetic before general anaesthesia (n = 10) Control group: intrathecal morphine (n = 11) General anaesthesia for all participants
Outcomes	Pain: "Pain relief was better in the epidural group (P = 0.019), in the first postoperative day"
Notes	Conference abstract Data not extractable. No address available to contact study authors
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"we 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	No drop‐outs mentioned
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Low risk	Groups well balanced: "Demographic and surgical characteristic were similar in both groups"