Choi SJ 2012.

Methods	Randomized, controlled trial. No information provided on random sequence generation and allocation concealment. Participants and outcome assessors were blinded. Anaesthesiologists were unblinded. The study aimed to examine whether intraoperative systemic lidocaine may present beneficial effects on the recovery of bowel function, pain intensity, and analgesic consumption in patients undergoing various breast plastic surgeries. The study was conducted in Korea. Date not published.
Participants	Number assessed for eligibility: N/A Number randomized: 60→ 30:30 Number analysed: (30:28:26)/(30:27:22) at 24 hrs: 48 hrs: 72 hrs postoperatively. Inclusion criteria Female patients, aged 20 to 60 years, ASA I to II, elective breast plastic surgeries. Exclusion criteria Severe hepatic, renal, cardiac, respiratory, or endocrine diseases, morbid obesity, or allergies to local anaesthetics. Episodes of intraoperative hypotension (mean BP < 60 mmHg) or bradycardia (heart rate < 40 beats/min), arrhythmia or urticaria associated with lidocaine infusion were also criteria for exclusion. Baseline details Experimental group (n = 30) Mean age (years): 41 M = 0%, F = 100% Mean weight (kg): 56 ASA I/II: N/A Mean duration of surgery (min): 295 Main surgical procedures (n): Augumentation mammaplasty (8), reduction mammaplasty (1), tissue expander removal + augmentation mammaplasty (single/both, 3:4), breast reconstruction with flap (10), mastectomy with implant (4) Control group (n = 30) Mean age (years): 40 M = 0%, F = 100% Mean weight (kg): 55 ASA I/II: N/A Mean duration of surgery (min): 288 Main surgical procedures (n): augumentation mammaplasty (5), reduction mammaplasty (1), tissue expander removal + augmentation mammaplasty (single/both, 5:2), breast reconstruction with flap (11), mastectomy with implant (6)
Interventions	Experimental group (30 patients) 1.5 mg/kg bolus of lidocaine approximately 30 min before incision followed by continuous infusion of lidocaine (1.5 mg/kg/hr) until skin closure. Control group (30 patients) The control group was untreated.
Outcomes	The primary endpoint of the study was restoration of bowel function after surgery. Dichotomous Postoperative nausea and vomiting reported at 24 hrs, 48 hrs, and 72 hrs Side effects (dizziness, itching, respiratory depression) reported at 24 hrs, 48 hrs, and 72 hrs Level of satisfaction for pain control (excellent/satisfied/poor) at 72 hrs Number of patients with extra pain rescue analgesic medication Continuous Time to first flatus and first defaecation (hrs) Length of hospital stay (days) Pain score (VAS 0 to 10) at 24 hrs, 48 hrs, and 72 hrs Pethidine requirement during PACU (mg/patient); PCA (fentanyl/ketorolac) requirement at PACU ‐ 24 hrs, 24 to 48 hrs (ml) Intraoperative anaesthetic requirement (end tidal sevoflurane)
Notes	All female patients Small trial sample size (< 200 patients) Power analysis performed (bowel function, n = 20) Medication "No supplemental opioid was given to patients in either group during the maintenance of anaesthesia. For postoperative pain control, pethidine 0.5 mg/kg was provided within 30 min of the end of surgery and supplemented after recovery as needed with further boluses of 0.25 mg/kg at 20‐30 min intervals. Upon arrival to the post anaesthetic care unit (PACU), patients were connected to an intravenous patient controlled analgesic system (IVPCA) with fentanyl 1,500 μg and ketorolac 180 mg in 64 ml of saline (100 ml of total volume) to deliver a bolus of 1 ml of the above analgesics with a lockout time of 15 min and a basal rate of 1 ml/hr. After transfer to the ward, all patients received IVPCA, and extra rescue medications such as pethidine or NSAID according to body weight, if required." 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)	Unclear risk	Quote: " …patients…were randomly and equally divided to two groups". No information provided.
Allocation concealment (selection bias)	Unclear risk	No statement on allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: " participating patients … were all blinded to the patient's group assignment". "For the safety of patients, anaesthesiologists involved in the anaesthetic managements were not blinded to the groups. However, they were not involved in further management of postoperative pain control or data collection associated with this study".
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "...surgeons, and medical investigators who were involved in the data collection, were all blinded to the patient’s group assignment".
Incomplete outcome data (attrition bias) All outcomes	High risk	Dropout rate (experimental/control): at 48 hrs: 7%:10%; at 72 hrs: 13%:27% Outcome data 48 hrs and 72 hrs after surgery were incomplete. Withdrawals were not described. High dropout rate at 72 hrs.
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.