Siniscalchi 2003.

Methods	RCT Approved by the ethics committee and informed consent obtained Setting: Italy Funding: unspecified
Participants	70 ASA 1 to 3 patients (aged 18 to 70 years) undergoing liver or gallbladder cancer surgery through right subcostal incision
Interventions	Treatment group: TEA (T9‐T10 with the catheter inserted 5 cm passed the needle tip) with ropivacaine 0.2% 7 mL/h intraoperatively and 5 mL boluses for an unspecified duration after surgery (n = 35) Control group: IV morphine (n = 35) General anaesthesia for all participants
Outcomes	Vomiting
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"randomized", 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