Onan 2013.

Methods	Parallel RCT Ethics committee: approved by the Institutional Ethics Committee Informed consents: informed written consents were obtained from each patient Site: Istanbul Florence Nightingale Hospital, Istanbul, Turkey Setting: unspecified Dates of data collection: between April 2009 and March 2010 Funding: unspecified Registration: unspecified
Participants	40 participants; mean age: 58.5 years; sex distribution: 4 females and 36 males Inclusion criteria Patients with ischaemic heart disease scheduled for elective CABG Exclusion criteria LEVF < 40% Emergency operation Previous cardiothoracic operation Unstable angina Resting bradycardia (< 60 beats/min) Critical left main coronary artery disease (> 50% stenosis) Contraindications for the epidural technique including preexisting coagulopathy Preoperative anticoagulation (full therapeutic doses of standard or low‐molecular‐weight heparin, warfarin, thrombolytic drugs, or potent antiplatelet drugs) Systemic or local infection Previous cervical or upper thoracic operation Vertebral deformity Drug hypersensitivity Long‐term use of non‐steroidal anti‐inflammatory drugs Use of tranquillizers Inability to express themselves verbally Inability to fill out the questionnaires
Interventions	Intervention Epidural analgesia (N = 20) Comparator Systemic analgesia (N = 20) Premedication: midazolam Induction: midazolam, fentanyl, and rocuronium Maintenance: nitrous oxide, rocuronium, propofol, and fentanyl Surgery: CABG with CPB using a membrane oxygenator
Outcomes	Relevant to this review Risk of myocardial infarction Risk of pulmonary complications (pneumonia) Risk of atrial fibrillation or atrial flutter Risk of neurological complications (cerebrovascular accident or epidural haematoma or abscess) Tracheal intubation Pain scores Others Acute kidney injury ICU length of stay Hospital length of stay
Notes	Correspondence: email sent 16 March 2018; no reply Conflict of interest: study authors acknowledge no conflict of interest in the submission DOI: 10.1111/jocs.12086
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomization was performed immediately before surgery using sealed envelopes
Allocation concealment (selection bias)	Low risk	Randomization was performed immediately before surgery using sealed envelopes
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	No loss to follow‐up mentioned
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Low risk	No failed epidural reported Groups well balanced