Mitchell 2009.

Methods	Randomized, placebo‐controlled trial. No detailed information on random sequence generation and allocation concealment provided. Participants and personnel were blinded. No statement on blinding of outcome assessors. This study aimed to test the benefit of a 12‐hour infusion of lidocaine in a broader group of cardiac surgery patients, including those undergoing CABG surgery. The study was conducted in New Zealand. Date not published.
Participants	Number assessed for eligibility: 639 Number randomized: 158 → 81:77 Number analysed: 80:77 (outcome: length of hospital stay), 59:59 (analysed at 10 weeks), 54:53 (analysed at 25 weeks) Inclusion criteria Adult patients (20 to 75 years old) undergoing CABG (with or without cardiopulmonary bypass), valve surgery, or combined procedures; resident in the greater Auckland area, English speaker, no preexisting cerebral dysfunction, no history of sensitivity to lidocaine, and no condition the procedural anaesthesiologist would normally consider to be a contraindication to lidocaine administration. Exclusion criteria N/A Baseline details Experimental group (n = 81) Mean age (years): 61.5 M = 74.1%, F = 25.9% Mean weight (kg): 82.9 ASA I/II: N/A Duration of surgery (min): N/A Main surgical procedure (n): aortic valve replacement (3), mitral valve replacement (5), aortic valve replacement + mitral valve replacement (1), CABG on pump (58), off‐pump CABG (10), valve plus CABG (4) Control group (n = 77) Mean age (years): 58.1 M = 81.8%, F = 18.2% Mean weight (kg): 83.2 ASA I/II: N/A Duration of surgery (min): N/A Main surgical procedure (n): aortic valve replacement (3), mitral valve replacement (1), aortic valve replacement + mitral valve replacement (0), CABG on pump (54), off‐pump CABG (8), valve plus CABG (11)
Interventions	Experimental group (81 patients) The infusion was started at induction of anaesthesia with a “bolus” of 1 mg/kg over 5 minutes followed by 2 mg/min for 2 hours, and 1 mg/min thereafter, for a total of 12 hours. Control group (77 patients) Control patients received saline as placebo.
Outcomes	The primary endpoint of the study was neurocognitive deficit. Dichotomous Serious adverse events (mortality) Number of patients with at least one declined test score value 10 weeks after surgery Continuous Length of ICU stay (hrs), (data presented as median with IQR) Length of hospital stay (days), (data presented as median with IQR, asymmetric distribution) Neuropsychologic test score (based on different performance tests, self‐rating inventory, and control tests) at the preoperative assessment and the sequential group mean percentage change score at 10 weeks and at 25 weeks after surgery
Notes	Small trial sample size (< 200 patients) Power analysis performed (neurocognitive deficit, n = 36 for 10 weeks, n = 91 for 25 weeks) Medication N/A Anaesthesia The anaesthesia regime was not standardized. ("There was no attempt to rigidly standardize the anesthetic technique, but practice among anesthesiologists was confluent, and no significant changes occurred over the course of the study") Funding "This work was supported by medical equipment grant AP72364 from the Lottery Grants Board of New Zealand, grants 81354 and 81399 from the Auckland Medical Research Foundation, and by a grant from the English Freemasons of New Zealand."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "a collaborator who had no other role in the trial generated a block‐randomized sequence of allocations." No detailed information provided.
Allocation concealment (selection bias)	Low risk	Quote: "this sequence was concealed from the patients, all medical staff in contact with the patients, and from all other trial collaborators.", "Trial solutions...were repackaged into generic vials by a licensed pharmaceutical company."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "trial solutions...were repackaged into generic vials by a licensed pharmaceutical company."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No statement on blinding of outcome assessors.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Dropout rate (experimental/control): 1%:0% Withdrawals, losses during follow‐up etc. were described. It is unclear from the description whether the reasons (e.g. postoperative complications) may be related to true outcome (neurophysiological testing). However, the relevant outcome for the current review (length of hospital stay) remains unaffected.
Selective reporting (reporting bias)	Unclear risk	There is no reference to a trial registry and no published study protocol.
Other bias	Low risk	The study appears to be free of other sources of bias.