Loick 1999.

Methods	Parallel RCT Ethics committee: approved by the local ethical committee Informed consents: all study participants gave written consent Site: Munster, Germany Setting: university hospital Dates of data collection: unspecified Funding: departmental/institutional Registration: unspecified
Participants	70 participants, for the participants included in this review: mean age: 61.9 years; sex distribution: 9 females and 37 males Inclusion criteria Patients scheduled for elective coronary artery bypass grafting Exclusion criteria Disorders of the intestine and liver Gastritis Ulcera ventriculi and duodeni Autonomic neuropathy Diabetes mellitus (patients receiving insulin or oral hypoglycaemic drugs)
Interventions	Intervention Epidural analgesia (N = 25) Comparator Systemic analgesia (N = 21) Induction: sufentanil, propofol, and pancuronium Maintenance: sufentanil and propofol Surgery: CABG with CPB using hollow fibre oxygenator
Outcomes	Relevant to this review Risk of mortality Risk of myocardial infarction Haemodynamic variables Other Stress markers
Notes	Correspondence: email sent 16 March 2018; no reply Conflict of interest: none reported DOI: n/a The trial contains a third group given IV clonidine and not retained for analysis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote. "The patients were randomly allocated to one of the following three study groups"; no details provided
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	"Post hoc, two patients in the control group, who underwent repeat thoracotomy due to surgical bleeding, were excluded from the study"
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Low risk	Epidural blockade was performed successfully in all participants without any observed complications The groups were comparable with respect to previous myocardial infarction, preoperative medication of β‐blockers, and vasoactive substances. All participants had 2‐ to 3‐vessel coronary artery disease, and all, except 1 in each group, received a left internal mammary artery graft to bypass stenosis of the left descending artery