Jangra 2016.

Methods	RCT, parallel design
Participants	Total number of randomized participants: 20 Inclusion criteria: ASA I or II; scheduled for endoscopic sinus surgery Exclusion criteria: people on beta‐blockers and cardiovascular active drugs; major hepatic, renal or cardiac disease; haematological disorders; allergic to magnesium sulfate; history of neromuscular disorder; diabetic neuropathy; pregnancy; prior treatment with opioids or anticoagulants Type of surgery: elective endoscopic sinus surgery Baseline characteristics Intervention group (esmolol) Age, mean (SD): 26.7 (± 8.3) years Gender, M/F: 3/7 ASA status I/II: 10/0 Control group (placebo) Age, mean (SD): 31.9 (± 9.0) years Gender, M/F: 6/4 ASA status I/II: 9/1 Country: India Setting: single centre; hospital
Interventions	Intervention group (esmolol) Randomized, n = 10; losses = 0; analysed, n = 10 (use of ITT analysis was not reported) Details: esmolol 500 µg/kg/min as an IV bolus over 10 min, after induction of anaesthesia, then infusion at the rate of 100‐300 µg/kg/min. We assumed discontinuation was at the end of anaesthesia Control group (placebo) Randomized, n = 10; losses = 0; analysed, n = 10 (use of ITT analysis was not reported) Details: normal saline given in same volumes as intervention group
Outcomes	Outcomes measured/reported by study authors: hypotension (MAP < 50 mmHg); hypertension; need for additional hypotensive agents or vasopressors; reflex tachycardia and arrhythmias; bradycardia (not defined, and data not reported); bronchospasm (data not reported); arrhythmias; recovery times; blood loss; assessment of surgical field for bleeding Outcomes relevant to the review: hypotension (see notes below)
Notes	Funding/declarations of interest: no sources of support, and study authors declare no conflicts Study dates: July 2007‐October 2008 Notes: study included an additional group (magnesium sulphate), which we did not include in this review we did not include data for hypotension in analysis because it was not clear whether study authors measured this outcome in the control group; study authors reported that no participants in the esmolol group had excessive hypotension
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Use of computerized programme for randomization
Allocation concealment (selection bias)	Low risk	See above
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants and surgeons were blinded to group allocation. However, study authors do not report whether anaesthetists were blinded to 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	Unclear risk	Study authors noted that the duration of surgery and anaesthesia were less in the esmolol group. It is unclear whether this may influence results