Thread by @PulmCrit

how did we get to our current paradigm of ventilator support?
- historical approaches included hanging upside down and rolling patients over barrels (prone ventilation! what's old is new again?)
- @adamdavidthomas at #HRreloaded

heterogeneity! variations in compliance and lung disease will drive differences in optimal ventilation strategy
- @adamdavidthomas at #HRreloaded

as soon as bellows started being used to ventilate, it became evident that excessive volume could cause harm! (previously, mouth-to-mouth resuscitation naturally prevented barotrauma)
- @adamdavidthomas at #HRreloaded

oxygen toxicity was discovered early on as well. furthermore, excessive oxygen might promote resorption atelectasis.
- @adamdavidthomas at #HRreloaded

barotrauma is discovered: electron microscopy of alveolus being ripped open
- @adamdavidthomas at #HRreloaded

denmark polio outbreak - 1500 medical students hand-bagged patients achieving mortality drop from 90% to 25%. critical care is born.
- @adamdavidthomas at #HRreloaded

ARDS discovered in the 60s. Value of PEEP is starting to be appreciated, but still using baby doses of PEEP.
- @adamdavidthomas at #HRreloaded

ARMA trial: lung protective ventilation in the modern era emerges.
- @adamdavidthomas at #HRreloaded

open lung strategy: recruit the lung & prevent de-recruitment. many efforts at this, but so far not a ton of success (e.g. failure of traditional recruitment maneuvers).
- @adamdavidthomas at #HRreloaded

lung strain is more than just the tidal volume: driving pressure and mechanical power could be more important.
- @adamdavidthomas at #HRreloaded

13,000 ventilated patients - both driving pressure & mechanical power both correlate with worse outcomes. mech power may be useful *integration* of numerous forms of respiratory badness.
- @adamdavidthomas at #HRreloaded

so where are we?
lung protective ventilation remains central.
other interesting goals - avoiding O2 toxicity, high driving pressure, excess power
- @adamdavidthomas at #HRreloaded