Table 1.

Study characteristics

Author	Study design	Participants	Intervention vs. control	Timeline	Primary outcome	Secondary outcome	Follow-up period	Drop outs	Risk of bias
Insler, 2009 [23]	Randomized double-blind placebo-controlled trial	n = 100; MS for CABG; mean age 63 years; 72% male	IV lidocaine infusion (n = 44) vs. placebo substitute (n = 45)	Anesthesia induction until either ICU dismissal or PO hour 48	VAS pain score at PO hours 4, 8, 16, 24, 48, 96	ICU hemodynamics; MI; extubation time; sedation score; PO fentanyl, midazolam, propranolol doses; ICU and hospital length of stay	ICU dismissal or PO hour 48	11	Some concerns
Kang, 2014 [24]	Randomized placebo-controlled trial	n = 45; MS for CABG, mean age 68 years; 67% male	Topical lidocaine 2% gel on chest tubes (n = 22) vs. normal saline placebo (n = 23)	Single application with intraoperative insertion of chest tubes	VAS pain scores at extubation and POD 1, 2, 3, 7	Cumulative PCA fentanyl PCA; number of PCA button pushes; chest tube worse site of pain	POD 7	3	Low
Mashaqi, 2018 [25]	Randomized, double-blind placebo-controlled trial	n = 40; MS for CABG; age and sex not reported	Intrapleural 12 mL 2% lidocaine (n = 20) vs. 12 mL 0.9% saline solution placebo (n = 20)	Single injection on POD 1 and 2; administered via left-sided double-lumen chest tube	NRS pain scores on POD 1 and POD 2	FEV1 before and after injections on POD 1 and POD 2	POD 2	0	High

CABG coronary artery bypass graft, MS median sternotomy, IV intravenous, ICU intensive care unit, MI myocardial infarction, POD postoperative day, PO postoperative, VAS visual analog scale, NRS numerical analog scale, PCA patient controlled analgesia, FEV1 forced expiratory volume at one second