Tedore 2011.

Study characteristics
Methods	Prospective, parallel‐arm RCT where patients in 1 arm received general anaesthesia (GA) and patients in the other arm received ultrasound‐assisted PVB with sedation in patients undergoing ambulatory breast cancer surgery
Participants	A total of 40 patients, with 18 in the GA group and 22 in the PVB group, were included
Interventions	PVB group (n = 22) Sedation for block: all patients received 1 to 4 mg midazolam (intravenous) and 0 to 2 mcg/kg fentanyl All patients received ultrasound‐assisted PVB from C7 to T4 with 3 mL of 1.5% mepivacaine and 3 mL of 0.5% bupivacaine at each level Sedation during surgery: administered with intravenous infusion of 50 to 100 mcg/kg/min of propofol GA group (n = 18) Pre‐medication: all patients received 1 to 4 mg midazolam (intravenous) Induction of anaesthesia was carried out with propofol, fentanyl with LMA, and additional fentanyl at the discretion of the anaesthesiologist; maintained using sevoflurane, air, and oxygen. Surgeons infiltrated 0.25% bupivacaine 0.5 to 1 mg/kg at incision site before closure
Outcomes	Primary outcome • Time to home discharge readiness Secondary outcomes • VAS, pain assessment (0 to 10) at 30, 60, 90, and 120 minutes after arrival • Narcotic consumption • Incidence of nausea and vomiting • Patient satisfaction
Notes	Unpublished study; study was sent to us by study authors as details on trial registry fulfilled our inclusion criteria and full‐text review of the study revealed that study fulfilled inclusion criteria in the meta‐analysis. Study authors were contacted for information on some other parameters; however this was not available Funding was received from the Department of Anesthesiology, New York Presbyterian Hospital Weill Cornell Medical College (institute where the study was carried out) Data for hospital stay and patient satisfaction score were expressed as median (IQR); these were converted to mean ± SD via Wan's method (Wan 2014) Patient satisfaction score was expressed on a 0 to 10 scale; this was converted to a 0 to 100 scale by multiplying by 10. This was done to enable the meta‐analysis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random number table was used
Allocation concealment (selection bias)	Low risk	Sealed envelopes were prepared by a research assistant who was not involved in the study
Blinding of participants and personnel (performance bias) All outcomes	High risk	This was not possible
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinded anaesthesiologist and PACU nurse recorded the data
Incomplete outcome data (attrition bias) All outcomes	Low risk	All 40 patients were included for outcome data
Selective reporting (reporting bias)	Low risk	Complications and benefits of both techniques have been reported
Other bias	Low risk	No other risk of bias was apparent