Ismail 2008.

Methods	Randomized, placebo‐controlled trial. No statement on blinding of participants, personnel, and outcome assessors within the abstract. This study was designed to assess the effect of lidocaine infusion on perioperative stress response, propofol and alfentanil consumption intraoperatively, recovery characteristics and postoperative analgesia during total intravenous anaesthesia in patients undergoing discectomy. The study was conducted in Egypt. Date not published.
Participants	Number assessed for eligibility: N/A Number randomized: N/A → 30:30 Number analysed: N/A Inclusion criteria Patients scheduled to undergo lumbar discectomy. Exclusion criteria N/A Baseline details Experimental group (n = 30) Mean age (years): N/A M = N/A, F = N/A Mean weight (kg): N/A ASA I/II: N/A Duration of anaesthesia (min): N/A Main surgical procedure (n): lumbar discectomy Control group (n = 30) Mean age (years): N/A M = N/A, F = N/A Mean weight (kg): N/A ASA I/II: N/A Duration of anaesthesia (min): N/A Main surgical procedure (n): lumbar discectomy
Interventions	Experimental group (30 patients) Thirty minutes before anaesthesia induction, the patients in the lidocaine group received lidocaine bolus i.v. injection of 1.5 mg/kg, followed by an i.v. infusion of 1.5 mg/kg/hr until 10 minutes after extubation. Control group (30 patients) Thirty minutes before anaesthesia induction, the control group received a 0.1 ml/kg i.v. bolus of 0.9% saline, followed by a constant infusion at 0.1 ml/kg/hr continued until 10 minutes after extubation.
Outcomes	The authors stated within the abstract "Hemodynamic variables, plasma cortisol, propofol and alfentanil consumption, postoperative pain scores and analgesic rescue requirement were recorded." No detailed information provided within the abstract.
Notes	Abstract only. No response on full text request from the authors as well as the journal. No relevant data for this review. Small trial sample size (< 200 patients).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "sixty patients undergoing lumbar discectomy were randomly allocated to receive lidocaine (Lidocaine group) or saline (Control group)…". No method of randomization described within the abstract.
Allocation concealment (selection bias)	Unclear risk	No statement within the abstract.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No statement within the abstract.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No statement within the abstract.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No statement within the abstract.
Selective reporting (reporting bias)	Unclear risk	There is no reference to a trial registry and no published study protocol.
Other bias	Unclear risk	There is no assessment possible due to publication; in abstract form only.