Equal increases in respiratory system elastance reflect similar XXXX in experimental ventilator-induced lung injury.

@entity548 @entity4 @entity26 @entity358 @entity35 @entity130
OBJECTIVE: We hypothesized that a 50% increase in respiratory system elastance (Ers) would indicate similar degree of @entity358 (equi-damage, ED), independently of ventilation strategy. DESIGN AND SETTING: A prospective, randomized animal laboratory investigation at a university hospital laboratory. SUBJECTS: 35 anesthetized, paralyzed, mechanically ventilated male @entity35 . INTERVENTIONS: Each @entity35 was ventilated with a different combination of tidal volume, positive end-expiratory pressure, and inspired fraction of @entity26 . Ers was determined throughout the experiment; the studies were interrupted when Ers reached 150% (ED) of its baseline value, or after 5 h. MEASUREMENTS AND RESULTS: Lung wet to dry weight ratio (W/D) was assessed. Morphological damage of the lung was scored on a grading of perivascular @entity4 , @entity548 , and breaks in the alveolar septa to obtain a @entity130 score. Twenty-four @entity35 achieved an Ers of 150%: nine within 1 h (class 1), nine in 1-2 h (class 2), and six in 2-5 h (class 3). Eleven @entity35 did not reach the target 50% increase in Ers (class 4). W/D was higher in @entity35 that reached the target than in those that did not. W/D did not differ among @entity35 that reached ED. Similarly, the @entity130 score did not differ among classes 1-3 but was higher than class 4. CONCLUSIONS: In the setting of VILI a 50% increase in Ers corresponds to an equal level of @entity358 , irrespective of ventilatory setting and time of ventilation.
