El‐Tahan 2009.

Methods	Randomized, placebo‐controlled trial. No statement on allocation concealment. Participants, personnel, and outcome assessors were blinded. The study aimed to evaluate the effects of perioperative lidocaine on the haemodynamic and hormonal responses for caesarean delivery. The study was conducted in Saudi Arabia. Date not published.
Participants	Number assessed for eligibility: N/A Number randomized: 90 → 45:45 Number analysed: 45:45 Inclusion criteria Women (ASA I and II) with uncomplicated, singleton pregnancy of at least 36 weeks of gestation, who refused regional anaesthesia and were scheduled for elective caesarean delivery under general anaesthesia. Exclusion criteria History of cardiac, liver, or kidney diseases; allergy to amide local anaesthetics; epilepsy; those taking cardiovascular medications; those with pregnancy‐induced hypertension; evidence of intrauterine growth restriction or foetal compromise. Baseline details Experimental group (n = 45) Mean age (years): 28.1 M = 0%, F = 100% Mean weight (kg): 75.3 ASA I/II: N/A Mean duration of anaesthesia (min): 43.2 Main surgical procedures: caesarean section Control group (n = 45) Mean age (years): 26.5 M = 0%, F = 100% Mean weight (kg): 75.4 ASA I/II: N/A Mean duration of anaesthesia (min): 40.8 Main surgical procedures: caesarean section
Interventions	Experimental group (45 patients) Patients received an i.v. bolus of 1.5 mg/kg lidocaine 1.5% infused for 10 min, at 30 min before induction of anaesthesia, followed by constant infusion at 1.5 mg/kg/hrs of the same solution continued until 60 min after skin closure. Control group (45 patients) Placebo identical setting.
Outcomes	The primary endpoint of the study was post‐induction BP. Dichotomous Postoperative nausea and vomiting (observation period not described) Side effects (arrhythmia, light‐headedness, headache, perioral numbness, tunnel vision, seizures) Continuous Perioperative heart rate and MAP (data presented graphically) Plasma cortisol concentration (data presented graphically) Neonatal data (Apgar score 1 and 5 mins, neonatal adaptive capacity score at 15 mins, 2 hrs, 24 hrs, umbilical vein and artery acid‐base status
Notes	Only women, obstetrics Small trial sample size (< 200 patients) Power analysis performed (post‐induction BP, n = 45) Medication "Hydromorphone 0.4 mg IV was administered every 5 min to maintain a NRS pain score less than 4 out of 10. In cases of postoperative nausea or vomiting, subjects received 10 mg IV metoclopramide. Before PACU discharge, subjects were started on a PCA intravenous pump set to deliver 1 mg of intravenous morphine equivalent, no basal rate and lockout time of 10 min. Subjects also received 30 mg of intravenous ketorolac every 6 for 24 hrs. Total postoperative opioid consumption (24 hrs) was calculated in equivalent doses of intravenous morphine." Anaesthesia The anaesthesia regime was standardized in both groups. Funding No funding mentioned
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "the subjects were allocated randomly to two groups using a computer‐generated randomization code."
Allocation concealment (selection bias)	Unclear risk	No statement on allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: " another anaesthesiologist, who was blinded to the study solution, gave the anaesthetic and was instructed to avoid using local anaesthetics, and a third performed the assessments. All staff in the operating room were unaware of the randomization code."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "...and a third performed the assessments." No statement on blinding of outcome assessor.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals, no exclusions.
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.