Probst 2014.

Methods	Parallel‐group single‐blinded randomized controlled trial, conducted in Germany. Study conducted from May 2008 to July 2009
Participants	200 patients undergoing elective cardiac surgery (coronary artery bypass graft with or without valve surgery) who were haemodynamically stable The attending anaesthesiologist and the cardiac surgeon in consensus excluded those who were in cardiogenic shock, were dialysis dependent or had an additive EuroSCORE > 10 before surgery, as well as those with impaired left ventricular function (ejection fraction < 35%), cardiac assist devices preoperative or postoperative and cardiopulmonary instability (high inotropic support, lactate > 5 mmol/L, Horowitz index < 200) after surgery
Interventions	Early extubation group (100 participants): postoperative care in post‐anaesthetic care unit (PACU) with high physician‐to‐patient ratio of 1:3. Weaning protocol was driven by physician with good compliance. Participants were extubated as soon as criteria were met. Usual care group (100 patients): postoperative care in ICU with low physician‐to‐patient ratio of 1:12. Weaning protocol was mainly driven by nurse. Compliance with protocol was dependent on actual workload in the ICU. Participant was extubated when criteria were met, and when the overall situation in the ICU was favourable, as estimated by the physician. Extubation criteria (same for both groups): conscious and obeys commands, stable spontaneous ventilation with pressure support of 10 to 12 cm H2O, positive end‐expiratory pressure (PEEP) 5 cm H2O, fraction of inspired oxygen (FiO2) ≤ 0.4, haemodynamically stable, not bleeding (drain output ≤ 100 mL/h) and no significant electrocardiographic abnormalities
Outcomes	Time to extubation Length of stay in the ICU or in the PACU according to treatment allocation Length of stay in hospital Risk of tracheal reintubation Risk of renal failure (increase in postoperative serum creatinine ≥ 3 times the preoperative value, or serum creatinine > 150 μmol/L) Risk of stroke (new transient or permanent motor or sensory deficit of central origin or unexplained coma) Risk of hospital mortality
Notes	Power calculation done. Funding from Leipzig Heart Center, University of Leipzig. Study authors declare no conflict of interest in the study. Not included in reintubation subgroup analysis, as extubation occurred in different locations (PACU or ICU)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details given
Allocation concealment (selection bias)	Low risk	Sealed envelopes picked out of a box
Blinding (performance bias and detection bias) All outcomes	Low risk	Medical and nursing staff in ICU and PACU had been informed about the design and conduct of the study but were not informed as to which patients were enrolled in the study. Data collection and analysis were performed by an independent person who was not part of the anaesthetic, surgical or ICU team, and who was not blinded to treatment allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	423 patients consented to participated in the study at the premedication visit, 223 were excluded at the end of surgery because they met exclusion criteria at the end of surgery, or because PACU and ICU beds were not simultaneously available.
Selective reporting (reporting bias)	Low risk	Reported all outcomes collected
Other bias	Low risk	Groups were comparable at baseline except for duration of surgery and anaesthesia time.