But 2006.

Methods	RCT, parallel design
Participants	Total number of randomized participants: 30 Inclusion criteria: people with type II diabetes mellitus undergoing CABG surgery Exclusion criteria: type I diabetes mellitis; ejection fraction < 40%, liver and kidney insufficiency; bleeding diathesis; valvular heart disease Type of surgery: CABG Baseline characteristics Intervention group (esmolol) Age, mean (SD): 58 (± 6) years Gender, M/F: 8/7 History of MI, n: 7 History of hypertension, n: 5 Ejection fraction, mean (SD), %: 49 (± 5) Preoperative use of beta‐blockers, n: 4 Control group (placebo) Age, mean (SD): 57 (± 5) years Gender, M/F: 6/9 History of MI, n: 5 History of hypertension, n: 6 Ejection fraction, mean (SD), %: 51 (± 5) Preoperative use of beta‐blockers, n: 3 Country: Turkey Setting: single centre; hospital
Interventions	Intervention group (esmolol) Randomized, n = 15; losses = 0; analysed, n = 15 (use of ITT analysis not reported) Details: esmolol 500 µg/kg over 3 min before induction of anaesthesia, followed by infusion 100 µg/kg/min continued until 12 h postoperatively Control group (placebo) Randomized, n = 15; losses = 0; analysed, n = 15 Details: 20 mL normal saline over 5 min, followed by 20 mL/h normal saline
Outcomes	Outcomes measured/reported by study authors: amount of glucose‐insulin‐potassium infusion consumption; blood glucose levels; bradycardia (not defined), hypotension (not defined), hypertension; recovery times; length of hospital stay; dysrhythmias; inotropic support Outcomes relevant to the review: bradycardia; hypotension; length of hospital stay
Notes	Funding/declarations of interest: not reported Study dates: not reported Note: study included an additional group (magnesium), which we did not include in the review article in Turkish, translated with the help of D Azar (previous review author ‐ Blessberger 2018)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not specified
Allocation concealment (selection bias)	Unclear risk	Not specified
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Although the control group is given normal saline, it is not clear whether this is given as a placebo, and whether anaesthetists are aware of group allocation
Blinding of outcome assessors (detection bias) All outcomes	Unclear risk	Not specified
Incomplete outcome data (attrition bias) All outcomes	Low risk	No apparent losses
Selective reporting (reporting bias)	Unclear risk	Study authors did not report prospective clinical trial registration or publication of a protocol. It was not feasible to effectively assess risk of reporting bias
Other bias	Low risk	Not detected