Table 1 Baseline characteristics of the included trials

Gainnier et al. [28]

AECC criteria for ARDS with PaO₂/FiO₂ ratio < 150 at a PEEP ≥ 5 cm H₂O within 36 h

One bolus of 50 mg of cisatracurium infusion, followed by a continuous infusion at an initial rate of 5 μg/kg per min for 48 h

An infusion of saline at a rate of 4 mL/h

Assist-control mode for at least 48 h. Tidal volume 6–8 mL/kg of ideal body weight

Midazolam and sufentanil to obtain a Ramsay score of 6

Forel et al. [29]

AECC criteria for ARDS with PaO₂/FiO₂ ratio < 200 mmHg at a PEEP ≥ 5 cm H₂O within 48 h of onset

One bolus of 50 mg of cisatracurium infusion, followed by a continuous infusion at an initial rate of 5 μg/kg per min for 48 h

An infusion of saline at a rate of 4 mL/h

Assist/control-volume with a tidal volume of 4–8 mL/kg predicted body weight and a plateau pressure of ≤ 30 cm H₂O

Midazolam (3–30 mg/h) and sufentanil (10–150 μg/h) to obtain a Ramsay score of 6

Papazian et al. [10]

AECC criteria for ARDS with PaO₂/FiO₂ ratio < 150 mmHg at a PEEP ≥ 5 cm H₂O within 48 h

One bolus infusion of 15 mg of cisatracurium, followed by a continuous infusion of 37.5 mg per hour for 48 h

An infusion of saline at the same rate as NMBA group

Volume assist-control mode, with a tidal volume of 6 to 8 mL per kilogram of predicted body weight

Obtain a Ramsay score of 6

Lyu et al. [30]

Moderate to severe ARDS with a PaO2/FiO2 less than 150 with PEEP at least 5 within the first 48 h

One bolus infusion of 0.1 mg/kg vecuronium, followed by a continuous infusion of 0.05 mg/kg per hour for 24 to 48 h

Usual care

Volume control mode, with a tidal volume of 4 to 8 mL per kilogram of predicted body weight

Sedation of midazolam and sufentanil

Rao et al. [32]

Berlin criteria for moderate-to-severe ARDS

Continuous infusion of 1 μg/kg per min of vecuronium

Usual care

Protective ventilation strategy, with a tidal volume of 6 mL per kilogram of ideal predicted body weight, with a plateau pressure ≤ 30 cm H2O

Midazolam and sufentanil or midazolam and fentanyl with a Ramsay score of 2 to 4

Guervilly et al. [31]

Moderate to severe ARDS with a PaO2/FiO2 less than 150 with PEEP at least 5 within the first 48 h

Cisatracurium besylate was given using a 3-mL rapid intravenous infusion of 15 mg followed by a continuous infusion of 37.5 mg/h

Usual care

Volume-assist control mode with a tidal volume of 6 mL/kg/IPBW (ideal predicted body weight)

Midazolam and sufentanil to achieve a Ramsay score of 6

Moss et al. [21]

present for less than 48 h: PaO2:FiO2 of less than 150 mmHg with a PEEP of 8 cm or more of water

An intravenous bolus of 15 mg of cisatracurium, followed by a continuous infusion of 37.5 mg per hour for 48 h

An infusion of saline at the same rate as NMBA group

Protective ventilation strategy, with a tidal volume of 6 mL per kilogram of ideal predicted body weight, with a PEEP ≥ 8 cmH2O

A RASS score of 0 or − 1 in the control group