Carli 1997.

Methods	RCT Approved by the ethics committee and informed consent obtained Setting: Canada Funding: unspecified
Participants	12 patients undergoing elective gastrointestinal surgery for resection of non‐metastatic adenocarcinoma of the rectosigmoid colon Exclusion criteria were anaemia, diabetes mellitus, morbid obesity and severe cardiovascular disease
Interventions	Treatment group: thoracic (T8) epidural analgesia with 10 to 15 mL of 0.75% bupivacaine for a sensory block from T3 to S5 followed by 5 mL every 90 minutes during surgery and an infusion of 0.25% bupivacaine at 8 to 12 mL/h for 48 hours. Intramuscular papaveratum as required (n = 6) Control group: subcutaneous infusion of papaveratum at 3 to 8 mg/h (n = 6) General anaesthesia for all participants
Outcomes	Pain: Postoperative pain scores in the epidural group ranged from 0.6 to 1.6 at rest and from 2.3 to 4.1 on coughing. Pain scores in the control group ranged from 0.8 to 2.1 at rest and from 2.4 to 6.3 on coughing. No significant difference in pain scores at rest was observed between the 2 groups. In contrast, pain scores on coughing were lower in the epidural group (P value = 0.021)
Notes	Data not extractable; study authors contacted on 4 May 2015; informed us that data are no longer available Participants in the epidural group could not move on first postoperative day owing to a motor block
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	No loss to follow‐up
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Low risk	Groups well balanced