RT Journal Article SR Electronic T1 The Ratio of Inspiratory Pressure Over Electrical Activity of the Diaphragm Remains Stable During ICU Stay and Is Not Related to Clinical Outcome JF Respiratory Care FD American Association for Respiratory Care SP 495 OP 501 DO 10.4187/respcare.04400 VO 61 IS 4 A1 Giacomo Bellani A1 Andrea Coppadoro A1 Matteo Pozzi A1 Alfio Bronco A1 Daniela Albiero A1 Nilde Eronia A1 Valeria Meroni A1 Giacomo Grasselli A1 Antonio Pesenti YR 2016 UL http://rc.rcjournal.com/content/61/4/495.abstract AB BACKGROUND: We previously described an index, defined as the ratio between the inspiratory muscle pressure (Pmus) and the electrical activity of the diaphragm (EAdi) (Pmus/EAdi index). In the present work, we describe the trend of Pmus/EAdi index over time, investigating whether it could be an indicator of muscular efficiency associated with risk factors for diaphragmatic injury and/or clinical outcomes.METHODS: This work is a retrospective analysis of subjects with measurements of Pmus/EAdi index obtained, on different days, during assisted ventilation. Effects of Pmus/EAdi index absolute value on clinical outcomes were investigated dividing subjects into those with Pmus/EAdi index higher or lower than the median. Effects of Pmus/EAdi index trend over time were analyzed, distinguishing between subjects with Pmus/EAdi index increasing or decreasing.RESULTS: Mean Pmus/EAdi index was 1.04 ± 0.67, and the median (interquartile range) was 1.00 (0.59–1.34), without a systematic trend over the days. Demographic, ventilator, or outcome data did not significantly differ between subjects with Pmus/EAdi index higher or lower than the median. Similarly, we did not find relevant differences in subjects with Pmus/EAdi index increasing or decreasing over time.CONCLUSIONS: The Pmus/EAdi index value remained constant in each subject over time, although the inter-individual variability was high. Neither the Pmus/EAdi index nor its trends appeared to be associated with ventilatory variables or clinical outcome.