A 40-year-old with pneumonia is intubated on PEEP 10 cmH2O and FiO2 0.60 with PaO2 120 mmHg, bilateral infiltrates and no heart failure. The team debates ARDS presence and level. Which severity classification for ARDS using Berlin criteria should the therapist report?
Select an answer to reveal the explanation.
Short Explanation
You're doing quick math at the bedside that changes the whole care path. Nailing the ratio lets you sort mild from moderate without guessing.
Full Explanation
Berlin ARDS severity rests on PaO2 divided by FiO2 while on PEEP at or above 5 cmH2O with bilateral opacities not explained by cardiac failure, and 120 divided by 0.60 equals 200, which falls in the moderate range of greater than 100 to 200, so classification integrates timing, imaging, edema origin, and oxygenation with PEEP. Labeling mild misapplies the threshold because mild requires ratio greater than 200 to 300, which overestimates oxygenation here. Labeling severe misuses FiO2 and imaging alone because severe requires ratio at or below 100, far lower than calculated. Denying ARDS ignores that pneumonia commonly triggers ARDS and that absolute PaO2 without FiO2 context cannot exclude it. Exam caveat is to always calculate the ratio on the current PEEP rather than eyeballing FiO2 or PaO2 alone, and practical check is to confirm arterial sample timing, ventilator settings, chest imaging, and fluid status.