Liu 1986.

Methods	RCT, parallel design
Participants	Total number of randomized participants: 30 Inclusion criteria: ASA status I; no history of asthma, palpitations, hypertension, cardiac conduction defects, congestive heart failure or preoperative use of beta‐blockers Exclusion criteria: not reported Type of surgery: mainly hysterectomy and gynaecological procedures Baseline characteristics Intervention group (esmolol) Age, mean (SD): 45.6 (± 2.8) years Gender, M/F: 2/14 Control group (placebo) Age, mean (SD): 44.9 (± 3.3) years Gender, M/F: 1/13 Country: USA Setting: single centre; hospital
Interventions	Intervention group (esmolol) Randomized, n = 16; losses = 0; analysed, n = 16 (use of ITT analysis not reported) Details: esmolol 500 µg/k/min for 4 min; IV, during anaesthesia. Then 300 µg/k/min during induction of anaeshesia, and for a further 3 min Control group (placebo) Randomized, n = 14; losses = 0; analysed, n = 14 Details: normal saline, given same as intervention group
Outcomes	Outcomes measured/reported by study authors: haemodynamic variables; dysrhythmias (bradycardia, ventricular ectopic beats) during surgery; myocardial ischaemia (reported as ST depression); supraventricular arrhythmias Outcomes relevant to the review: bradycardia
Notes	Funding/declarations of interest: supported by a grant from American Critical Care Study dates: not reported
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	Low risk	Randomized, placebo‐controlled, double‐blind trial
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