Futier 2013.

Methods	RCT with parallel groups Approved by a central ethics committee (Comité de Protection des Personnes Sud‐Est I, Saint‐Etienne, France) according to French law. Written informed consent was obtained before randomization from each participant, on the day before surgery Site: multicentre at 7 French university teaching hospitals Setting: university hospital Dates of data collection: 31 January 2011 to 10 August 2012 ClinicalTrials.gov: NCT01282996
Participants	400 adults aged > 40 years, scheduled to undergo laparoscopic or non‐laparoscopic elective major abdominal surgery with an expected duration ≥ 2 hours, and a preoperative risk index for pulmonary complications > 2 (possible scores from 1 to 5 and a high score indicates a higher risk) Exclusion criteria: received mechanical ventilation within the 2 weeks preceding surgery, BMI ≥ 35 kg/m2, history of respiratory failure or sepsis within 2 weeks preceding surgery, requirement for intrathoracic or emergency surgery, or had a progressive neuromuscular illness
Interventions	Treatment group: tidal volume 6–8 mL/kg (IBW), PEEP 6–8 cmH2O and recruitment manoeuvres repeated every 30 min after tracheal intubation (30 cmH2O for 30 seconds) (n = 200) Control group: tidal volume 10–12 mL/kg (IBW), no PEEP and no recruitment manoeuvres (n = 200) During anaesthesia, a plateau pressure ≤ 30 cmH2O was targeted in each group. For episodes of arterial desaturation (defined as a peripheral oxygen saturation ≤ 92%), a transient increase in FiO2 to 100% was permitted, and in participants assigned to the control group, the use of PEEP, recruitment manoeuvres or both was allowed, if required.
Outcomes	Relevant to this review Pneumonia Non‐invasive ventilatory support Invasive ventilatory support ICU length of stay Mortality at 30 days Others Composite of major pulmonary and extrapulmonary complications
Notes	Funding: some authors declared consultant fees or travel expenses, or both, from industry Declaration of interest: Dr Futier reported receiving consulting fees from General Electric Medical Systems, lecture fees from Fresenius Kabi, and reimbursement of travel expenses from Fisher and Paykel Healthcare. Dr Constantin reported receiving consulting fees from Baxter, Fresenius Kabi, Dräger and General Electric Medical Systems; payment for expert testimony from Baxter, Dräger and Fresenius Kabi; lecture fees from General Electric Medical Systems, Dräger, Fresenius Kabi, Baxter, Hospal, Merck Sharp & Dohme and LFB Biomedicaments; payment for the development of educational presentations from Dräger, General Electric Medical Systems, Baxter and Fresenius Kabi; and reimbursement of travel expenses from Bird, Astute Medical, Astellas, Fresenius Kabi, Baxter and Hospal. Dr Paugam‐Burtz reported receiving consulting fees from Fresenius Kabi, lecture fees and reimbursement of travel expenses from Astellas, and payment for the development of educational presentations from LFB Biomedicaments and Merck Sharp & Dohme. Dr Allaouchiche reported receiving consulting fees from Fresenius Kabi and lecture fees from Novartis and Astellas. Dr Leone reported receiving consulting fees from LFB Biomedicaments and lecture fees from Fresenius Kabi and Novartis. Dr Jaber reported receiving consulting fees from Dräger France and Maquet France; lecture fees from Fisher and Paykel Healthcare, Abbott and Philips; and reimbursement of travel expenses from Pfizer. No other potential conflict of interest relevant to this article was reported. 30‐day follow‐up period Volume per body weight: predicted body weight calculated based on the equation used by the ARDS Network in their clinical trials: predicted body weight: men: 50 + 0.91 (height in cm – 152.4); women: 45.5 + 0.91 (height in cm – 152.4)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "randomization was performed with the use of a computer‐generated assignment sequence and a centralized telephone system." Quote: "randomization was stratified according to study site and the planned use or nonuse of postoperative epidural analgesia."
Allocation concealment (selection bias)	Low risk	Quote: "randomization was performed with the use of a computer‐generated assignment sequence and a centralized telephone system."
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "treatment assignments were concealed from patients, research staff, the statistician, and the data and safety monitoring committee. Staff members who collected data during surgery were aware of the group assignments."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "outcome assessors were unaware of these assignments throughout the study."
Incomplete outcome data (attrition bias) All outcomes	Low risk	3 participants were excluded after randomization; surgery was stopped prematurely in 2 of the 3 participants because of extensive illness (duration of surgery, < 2 hours), and 1 had undergone randomization in error (violation of exclusion criteria). An additional 3 participants were thus randomly assigned to a study group to obtain the full sample.
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Low risk	Groups well balanced Quote: "there was no industry support or involvement in the trial."