The Comparison of Spontaneous Breathing and Muscle Paralysis in Two Different Severities of Experimental Lung Injury*

Abstract

In animals with mild lung injury, spontaneous breathing was beneficial to lung recruitment; however, in animals with severe lung injury, spontaneous breathing could worsen lung injury, and muscle paralysis might be more protective for injured lungs by preventing injuriously high transpulmonary pressure and high driving pressure.

The Ratio of Inspiratory Pressure Over Electrical Activity of the Diaphragm Remains Stable During ICU Stay and Is Not Related to Clinical Outcome

“…The latter value has an important clinical implication, since it is becoming more evident that spontaneous breathing during mechanical ventilation can have both negative and positive consequences, 17 whose balance probably depends on the severity of lung injury 18 and the level of assistance, since both over-and underassistance of patients can be associated with adverse consequences. Whereas overassistance is associated with the risk of elevated tidal volumes and asynchronies, 19 an insufficient assist level results in large negative pressure swings that can severely injure the lungs 18,20 or the diaphragm itself 21 and cause increased oxygen consumption. 22 Moreover, had the P mus /EA di index value been relatively constant among all different subjects, one could calculate the P mus just from the EA di , without the need of an occluded airway pressure measurement (eg, in non-intubated subjects).…”

Esophageal and transpulmonary pressure in the clinical setting: meaning, usefulness and perspectives

“…This results from the increase in P L obtained by lowering P pl (P L = Paw − P pl ) [32]. However, this protective role has generally been suggested in patients with less severe ARDS and modest spontaneous demands [34,35]. Accumulating evidence indicates that spontaneous breathing might become deleterious in severe ARDS cases, as suggested by the beneficial effect of muscle paralysis observed in patients with severe ARDS [35,36].…”

Ventilation-induced lung injury exists in spontaneously breathing patients with acute respiratory failure: No

“…However, there is experimental evidence that SB can also cause or worsen lung injury during mechanical ventilation [6,7] through mechanisms that include negative intrathoracic and increased transalveolar pressure with lack of control of tidal volume (VT), ventilation inhomogeneity and cyclic and static overinflation [8].…”