Fig. 3From: Individual response in patient’s effort and driving pressure to variations in assistance during pressure support ventilationPatterns of response changes in pressure support (PS) level in two representative patients. Active patients react to a consistent decrease in pressure support by developing pressure by their respiratory muscles (pressure-muscle-index, PMI), hence keeping plateau pressure (Pplat) and tidal volume (Vt) relatively constant (upper left panel). On the opposite, a “quasi-passive patient” is almost passively inflated by the ventilator after opening the trigger (upper right panel). When PS is decreased, a fall in Pplat and Vt is observed. Surface electromyography (sEMG) data (lower panels) are consistent with this interpretation. ∆P, driving pressure; EADi,surf, surface electromyography of the diaphragm; Intercost,surf, surface electromyography of the intercostal musclesBack to article page