0990. Role of amplitude and rate of deformation in ventilator-induced lung injury
© Protti et al; licensee Springer. 2014
Published: 26 September 2014
Increasing both Tidal Volume (VT) (amplitude of lung deformation) and Inspiratory Flow (V') (rate of lung deformation) augments incidence of Ventilator-Induced Lung Injury (VILI) .
To clarify whether increasing V' at constant VT augments incidence of VILI.
Twenty-eight healthy piglets were mechanically ventilated for up to 54 hours. Each animal was assigned to one of three groups of VT (300-400 ml; 500-600 ml; 750 ml) and one of two groups of V'. Lower and higher V' were obtained by setting inspiratory-to-expiratory time ratio as high as 1:2 or as low as 1:9. Respiratory rate was always 15 breaths per minute. Interplay between VT and V' was assessed at the beginning of the study as airway pressure-volume loop area (or dynamic respiratory system hysteresis). VILI was defined as pulmonary oedema (lung weight gain ≥10% across the study period).
Inspiratory flow and incidence of VILI
VT 300-400 ml
VT 500-600 ml
VT 750 ml
Tidal volume (ml)
Inspiratory flow (ml/sec)
Incidence of VILI
Increasing V' (rate of lung deformation) while maintaining VT (amplitude of lung deformation) constant augments incidence of VILI. Further studies are needed to clarify whether dynamic respiratory system hysteresis is an independent predictor of VILI.
This study was supported in part by an Italian grant provided by Fondazione Fiera di Milano for Translational and Competitive Research (2007, Luciano Gattinoni) and by GE Healthcare.
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