LAUSR

Introduction: Mechanical power (MP) in pediatric patients hasn’t been well described yet. Aims and objectives: We investigated MP in children with and without ARDS (controls) during mechanical ventilation at different tidal volumes (TV). Methods: Flow and airway pressure (Paw) were recorded during mechanical ventilation in children (11 with ARDS, 9 controls) at TV 8, 10, 12 mL/kg, PEEP 5 cmH 2 O, respiratory rate (RR) adjusted to maintain constant minute ventilation. MP-functional residual capacity (MP/FRC) ratio, computed as the area between the inspiratory limb of Paw-TV curve and the TV axis, times RR and divided by FRC, was compared across different clinical and ventilatory conditions. Results: MP/FRC increases linearly with TV (Fig. 1A) both in ARDS (MP/FRC=2+19.6*TV/IBW, r 2 =0.99, p=0.07) and controls (MP/FRC=2.4-3.3*TV/IBW, r 2 =0.87, p=0.23). Moreover, at each TV, ARDS children have significantly higher MP/FRC than controls (p=0.0003 at TV 8 mL/kg; p=0.0008 at TV 10 mL/kg; p=0.0008 at TV 12mL/kg) (Fig. 1B). Conclusions: MP/FRC increases linearly with tidal volume, despite the reduction in RR. Moreover, MP/FRC is significantly higher in ARDS compared to control children, despite MP was normalized for FRC measured by helium dilution at the same time of flow and Paw registration. References [1] Gattinoni L. Intensive Care Med 2016; 42:1567