Just to remind everyone: Pulmonary 03 evaluates whether adult general anesthesia cases with
intubation receive a median PEEP of at least 2 cm H₂O. This was designed to distinguish cases with no
PEEP from those with some PEEP, since providing PEEP is a lung-protective strategy.
The key question was whether there’s been any new evidence in the past few years to support changing
the threshold or structure of the measure. The short answer: Literature continues to support low-level
PEEP as standard of care but does not support a higher universal target.
I looked at recent trials and meta-analyses from the past three years. They confirm what we already
know: Lung-protective ventilation with low tidal volume and some degree of PEEP decreases
postoperative pulmonary complications compared with high tidal volume and zero PEEP. There is
consistent harm with ZEEP (zero PEEP), which validates the lower boundary of this measure.
Data does not support fixed higher PEEP (like 8 or 10). Several large analyses show no improvement in
complications and even potential harm, such as intraoperative hypotension or arrhythmia, when PEEP is
pushed to higher arbitrary limits.
Regarding one-lung ventilation, Nirav shared a recent study—the PROTHOR trial—which is probably the
most influential new study in this area. It compared high PEEP (10) versus low PEEP (5) and found no
reduction in postoperative pulmonary complications with higher PEEP, but more hemodynamic events.
This underscores that PEEP should be individualized rather than defaulted to a high number like 10.
Since 2022, the most important shift is toward individualized PEEP titration. New trials discuss driving
pressure, compliance measurements, EIT (electrical impedance tomography), and recruitment-to-
inflation ratios. These show physiologic improvement and sometimes reduced complications, but
they’re not widely adopted yet.
The current rationale remains sound: PEEP prevents atelectasis, maintains alveolar recruitment, and
reduces postoperative pulmonary risk. Low levels of PEEP are safe and standard. Higher levels may be
appropriate in certain cases, but that depends on patient factors and hemodynamic tolerance. The
distinct risk occurs when PEEP is completely omitted, which this measure aims to prevent.
Inclusion and exclusion criteria remain appropriate: ASA 5 and 6, organ procurement, cases under 45
minutes, and one-lung ventilation are excluded. Success is defined as median PEEP ≥2 cm H₂O. This
threshold is not meant to define optimal care, only to prevent zero PEEP, which is avoidable harm.
There’s no literature suggesting increasing the threshold to 5, even though most machines default to 5.
Leaving it at 2 is fine for now.
Additional feedback: Dr. McComb mentioned a graph showing PEEP breakdown. We could add this to
the Pulmonary 03 summary page. It helps clinicians visualize PEEP trends across the department and
identify patterns. We might refine the bins for more nuance—currently 2–4 and 4–8 are small ranges.
Closing remarks: Since 2022, practice has shifted from fixed PEEP protocols to physiologic titration. Best
outcomes occur when PEEP matches lung mechanics rather than chasing a universal number. Pulmonary
03 should be viewed as a floor, not a target. It prevents harm by eliminating zero PEEP but doesn’t
capture complex adjustments for individual patients.