Critical care : the official journal of the Critical Care Forum
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Observational Study
Surface EMG-based quantification of inspiratory effort: a quantitative comparison with Pes.
Inspiratory patient effort under assisted mechanical ventilation is an important quantity for assessing patient-ventilator interaction and recognizing over and under assistance. An established clinical standard is respiratory muscle pressure [Formula: see text], derived from esophageal pressure ([Formula: see text]), which requires the correct placement and calibration of an esophageal balloon catheter. Surface electromyography (sEMG) of the respiratory muscles represents a promising and straightforward alternative technique, enabling non-invasive monitoring of patient activity. ⋯ These results support the use of surface electromyography as a non-invasive alternative for monitoring breath-by-breath inspiratory effort of patients under assisted mechanical ventilation.
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Oxygen (O2) toxicity remains a concern, particularly to the lung. This is mainly related to excessive production of reactive oxygen species (ROS). ⋯ The current evidence base suggests that PaO2 > 300 mmHg (40 kPa) should be avoided, but it remains uncertain whether there is an "optimal level" which may vary for given clinical conditions. Since even moderately supra-physiological PaO2 may be associated with deleterious side effects, it seems advisable at present to titrate O2 to maintain PaO2 within the normal range, avoiding both hypoxaemia and excess hyperoxaemia.