BACKGROUND: High tidal volume can cause ventilator-induced lung injury (VILI), but positive end-expiratory pressure (PEEP) is thought to be protective. We aimed to find the volumetric VILI threshold and see whether PEEP is protective per se or indirectly. METHODS: In 76 pigs (22 ± 2 kg), we examined the lower and upper limits (30.9-59.7 mL/kg) of inspiratory capacity by computed tomography (CT) scan at 45 cmH2O pressure. The pigs underwent a 54-h mechanical ventilation with a global strain ((tidal volume (dynamic) + PEEP volume (static))/functional residual capacity) from 0.45 to 5.56. The dynamic strain ranged from 18 to 100 % of global strain. Twenty-nine pigs were ventilated with end-inspiratory volumes below the lower limit of inspiratory capacity (group "Below"), 38 within (group "Within"), and 9 above (group "Above"). VILI was defined as death and/or increased lung weight. RESULTS: "Below" pigs did not develop VILI; "Within" pigs developed lung edema, and 52 % died before the end of the experiment. The amount of edema was significantly related to dynamic strain (edema 188-153 × dynamic strain, R (2) = 0.48, p < 0.0001). In the "Above" group, 66 % of the pigs rapidly died but lung weight did not increase significantly. In pigs ventilated with similar tidal volume adding PEEP significantly increased mortality.
Lung anatomy, energy load, and ventilator-induced lung injury / A. Protti, D.T. Andreis, M. Milesi, G.E. Iapichino, M. Monti, B. Comini, P. Pugni, V. Melis, A. Santini, D. Dondossola, S. Gatti, L. Lombardi, E. Votta, E. Carlesso, L. Gattinoni. - In: INTENSIVE CARE MEDICINE EXPERIMENTAL. - ISSN 2197-425X. - 3:1(2015 Dec), pp. 34.1-34.18.
|Titolo:||Lung anatomy, energy load, and ventilator-induced lung injury|
PROTTI, ALESSANDRO (Primo)
ANDREIS, DAVIDE TOMMASO (Secondo)
CARLESSO, ELEONORA (Penultimo)
GATTINONI, LUCIANO (Ultimo)
|Parole Chiave:||Energy load; Experimental animal model; Inspiratory capacity; Lung stress and strain; Mechanical ventilation; Ventilator-induced lung injury|
|Settore Scientifico Disciplinare:||Settore MED/41 - Anestesiologia|
|Data di pubblicazione:||dic-2015|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1186/s40635-015-0070-1|
|Appare nelle tipologie:||01 - Articolo su periodico|