Obersztyn 2018.

Methods	Parallel RCT Ethics committee: approved by the ethics committee Informed consents: written informed consents obtained Site: Medical University of Silesia in Katowice, Poland Setting: university hospital Dates of data collection: 18‐month period Funding: departmental/institutional Registration: unspecified
Participants	80 participants: mean age 59.6 years; sex distribution: 20 females and 60 males Inclusion criteria Patients scheduled for low‐risk CABG with or without CPB Exclusion criteria Contraindications for epidural anaesthesia (i.e. purulent skin lesions, significant spine deformations, abnormal basic haemostasis parameters) With no informed consent With chronic metabolic disease (except diabetes); with advanced respiratory, renal, or hepatic insufficiency With symptoms of circulatory insufficiency or unstable coronary disease and urgent qualification for the procedure Advanced respiratory insufficiency (forced expiratory volume 1 s < 50% of normal volume and/or presence of respiratory insufficiency in a preoperative arterial blood gas analysis) Study was discontinued if the following complications occurred: myocardial insufficiency requiring placement of an intra‐aortic balloon pump or other methods of mechanical support, symptoms of acute myocardial ischaemia, requirement for increased doses of inotropic drugs (dopamine and/or dobutamine up to 5 mcg/kg/min was acceptable), cumulative time of extracorporeal circulation exceeding 180 minutes, marked drainage, deterioration in blood gases or other problems requiring elective extubation, and other circumstances not listed in the protocol that could affect postoperative sedation or elective extubation. For patients with any complications mentioned above, only the operation period was analysed
Interventions	Intervention Epidural analgesia (N = 40) Comparator Systemic analgesia (N = 40) Premedication: oral midazolam Induction: etomidate, fentanyl, and pancuronium Maintenance: isoflurane, fentanyl, and 1 dose of morphine before wound closure Surgery: CABG with or without CPB
Outcomes	Relevant to this review Risk of mortality Risk of myocardial infarction Risk of pulmonary complications: respiratory depression Risk of neurological complications: risk of serious neurological complications from epidural analgesia (lasting > 3 months), sensory or motor deficit, or epidural haematoma Time to tracheal extubation Haemodynamic variables Others Rescue analgesia Arterial blood gases Intensive care unit length of stay Hospital length of stay Reoperation
Notes	Correspondence: email sent 18 November 2018; no reply Conflict of interest: none DOI: 10.5114/kitp.2018.76471
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Patients were assessed by the anaesthesiologists at least 12 hours before transfer to the operating theatre. Randomization was performed at this stage, by tossing a coin"
Allocation concealment (selection bias)	Low risk	From the information above, group treatment was unknown at enrolment
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	Study was discontinued if the following complications occurred: myocardial insufficiency requiring placement of an intra‐aortic balloon pump or other methods of mechanical support, symptoms of acute myocardial ischaemia, requirement for increased doses of inotropic drugs (dopamine and/or dobutamine up to 5 mcg/kg/min was acceptable), cumulative time of extracorporeal circulation exceeding 180 minutes, marked drainage, deterioration in blood gases or other problems requiring elective extubation, and other circumstances not listed in the protocol that could affect postoperative sedation or elective extubation. For patients with any complications mentioned above, only the operation period was analysed Analysis of the postoperative period was performed for 39 participants in each group because 2 participants were excluded from participation in the study according to the methodology In group I, 1 participant (operated on with the use of extracorporeal circulation) was excluded because of a serious haemorrhage that occurred immediately after transfer from the surgical theatre and required reoperation One exclusion occurred in group II (also in a participant operated on with the use of extracorporeal circulation) because of perioperative myocardial infarction diagnosed both in ECG and with elevated serum enzymes
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Low risk	Groups well balanced