LandmarkRCT

ARMA (ARDSNet)

Ventilation with Lower Tidal Volumes as Compared with Traditional Tidal Volumes for Acute Lung Injury and the Acute Respiratory Distress Syndrome

New England Journal of Medicine, 2000 · Multicenter, randomized controlled trial, unblinded

Clinical question

Does ventilating with a lower tidal volume reduce mortality compared with traditional tidal volumes in acute lung injury and ARDS?

Population: 861 patients with acute lung injury or ARDS across North American ARDS Network centers.
Inclusion criteria: Acute lung injury or ARDS by the contemporaneous consensus definition.
Already receiving mechanical ventilation.
Intervention: Tidal volume 6 mL/kg predicted body weight, with plateau pressure kept ≤ 30 cmH2O.
Comparator: Traditional tidal volume 12 mL/kg predicted body weight, with plateau pressure kept ≤ 50 cmH2O.
Primary outcome: All-cause in-hospital mortality before unassisted breathing.
Secondary outcomes: Ventilator-free days through day 28.
Result: The low tidal volume strategy reduced mortality compared with the traditional higher tidal volume strategy. (31.0% vs 39.8% mortality, p = 0.007)

What the trial found

Ventilating with 6 mL/kg predicted body weight and a plateau pressure ceiling of 30 cmH2O lowered mortality compared with 12 mL/kg ventilation, and trial enrollment was stopped early for benefit.

Current guideline position

The 2017 ATS/ESICM/SCCM guideline gives a strong recommendation for low tidal volume ventilation (approximately 4-8 mL/kg predicted body weight) with attention to plateau pressure, built directly on this trial.

Clinical interpretation

This trial established low tidal volume ventilation as the default strategy for essentially all patients with ARDS, largely independent of severity, and it anchors every major ARDS ventilation guideline written since.

Limitations

Unblinded, as is unavoidable for a ventilator-strategy trial.
The traditional-tidal-volume comparator (12 mL/kg) was higher than some contemporaneous practice, which may have widened the observed benefit.

High certainty

Clinical Context & Relevant Topics (1)

Disease Reference

Acute Respiratory Distress Syndrome

Acute, diffuse inflammatory lung injury causing hypoxemia and bilateral infiltrates not fully explained by cardiac failure or fluid overload.

View Topic Context →