ARDSNet (Acute Respiratory Distress Syndrome Network)

Question 1

ARDSNet Clinical Q

Answer 1

In patients with ALI/ARDS receiving mechanical ventilation, how does a lung protective strategy using lower tidal volumes compare with traditional ventilation protocols in decreasing mortality and ventilator-free days?

Question 2

ARDSNet Bottomline

Answer 2

In patients with ARDS, low tidal volume ventilation (initial TV 6ml/kg PBW) had lower mortality and more ventilator-free days.

Question 3

ARDSNet Primary Outcome

Answer 3

ventilator free days, mortality at 120 days

Question 4

ARDSNet nnt

Answer 4

11

Question 5

ARDSNet groups

Answer 5

-starting at 6 ml/kg PBW, reduced stepwise by 1 ml/kg PBW to maintain plateau pressure ≤30 cmH2O -starting at 12 ml/kg PBW, reduced stepwise by 1 ml/kg PBW to maintain plateau pressure ≤50 cmH2O

Question 6

ARDSNet criticisms

Answer 6

1. The trial studied more than just low Vt ventilation; a standardized PEEP protocol was used as well.
2. The mortality benefit may be from improved oxygen delivery to tissues rather than progression of lung disease.
3. The mortality benefit in the low Vt group may have been because the traditional Vt group had unnecessarily high Vt.
4. The traditional Vt group may not have been subjected to the best known therapy — an intermediate tidal volume (10 mL/kg of PBW) therapy was utilized at multiple centers at the time.
5. The investigators may have, therefore, submitted the participants to unnecessary harm. The informed consent educational materials was deemed to have “failed to describe adequately the reasonably foreseeable risks and discomforts” by the OHRP.