Miller 1976.

Methods	RCT Setting: Canada Funding: governmental
Participants	Adults > 30 years scheduled for elective (open?) cholecystectomy. Some patients had received additional interventions. No cardiopulmonary disease but 30% smokers
Interventions	Treatment group: LEA (T12‐L3). Repeated epidural lidocaine bolus (n = 10) Control group IM meperidine (n = 10)
Outcomes	Length of hospital stay
Notes	No specific a priori discharge criteria
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 mentioned
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Low risk	Groups well balanced