TY - JOUR 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 DO - 10.4187/respcare.04400 SP - respcare.04400 AU - Giacomo Bellani AU - Andrea Coppadoro AU - Matteo Pozzi AU - Alfio Bronco AU - Daniela Albiero AU - Nilde Eronia AU - Valeria Meroni AU - Giacomo Grasselli AU - Antonio Pesenti Y1 - 2016/02/16 UR - http://rc.rcjournal.com/content/early/2016/02/16/respcare.04400.abstract N2 - BACKGROUND: We previously described an index, defined as the ratio between the inspiratory muscle pressure (Pmus) and the electrical activity of the diaphragm (Edi) (Pmus/Edi index). In the present work, we describe the trend of Pmus/Edi 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/Edi index obtained, on different days, during assisted ventilation. Effects of Pmus/Edi index absolute value on clinical outcomes were investigated dividing subjects into those with Pmus/Edi index higher or lower than the median. Effects of Pmus/Edi index trend over time were analyzed, distinguishing between subjects with Pmus/Edi index increasing or decreasing.RESULTS: Mean Pmus/Edi 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/Edi index higher or lower than the median. Similarly, we did not find relevant differences in subjects with Pmus/Edi index increasing or decreasing over time.CONCLUSIONS: The Pmus/Edi index value remained constant in each subject over time, although the inter-individual variability was high. Neither the Pmus/Edi index nor its trends appeared to be associated with ventilatory variables or clinical outcome. ER -