PT - JOURNAL ARTICLE AU - Suvarna Gadgil AU - Diana Jansen AU - Jonne Doorduin AU - Lisanne Roesthuis AU - Hans van der Hoeven AU - Leo Heunks TI - Validation of indices to assess respiratory muscle effort in ventilated ICU patients AID - 10.1183/13993003.congress-2016.PA1339 DP - 2016 Sep 01 TA - European Respiratory Journal PG - PA1339 VI - 48 IP - suppl 60 4099 - http://erj.ersjournals.com/content/48/suppl_60/PA1339.short 4100 - http://erj.ersjournals.com/content/48/suppl_60/PA1339.full SO - Eur Respir J2016 Sep 01; 48 AB - Background: Too high levels of assist under mechanical ventilation is associated with atrophy and dysfunction of respiratory muscles. Monitoring respiratory muscle activity may therefore be of clinical importance. 'Patient-ventilator breath contribution' (PVBC) and 'pressure-electrical activity index' (PEi) are indices to assess respiratory muscle effort during mechanical ventilation, but reproducibility and repeatability have not been investigated.Aims: 1. Assess repeatability coefficient (RC) of PVBC and PEi2. Investigate how these indices change during the first 72 hrs3. Estimate inspiratory effort of the diaphragmMethods: Twenty-nine mechanically ventilated adult ICU patients were included. Diaphragm EMG activity (Edi) was assessed using dedicated esophageal catheter (Edi catheter). PVBC (tidal volume no assist/Edi no assist)/(tidal volume assist/Edi assist) and PEi (delta Paw/Edi) during end-expiratory occlusion were calculated at inclusion, after 12, 24 and 72 hrs and repeated 5 times with a 1-minute interval. Outliers were excluded from analysis. Pressure generated by the diaphragm (Pmus) was calculated by PEi * Edi-peak.Results: Mean PVBC at T=0 was 78% and decreased until 72% at T=72. The RC at T=0 was 11%. Mean PEi at T=0 was 1.12 cmH2O/µV, 1.25 at T=12, 1.07 at T= 24 and 0.87 at T=72. The RC at T=0 was 0.15 cmH2O/µV.Mean Pmus at T=0 was 9.0 cmH2O and increased until 10.2 cmH2O at T=72.Conclusion: Measurement of PVBC and PEi is feasible in routine clinical care. Repeatability of both indices is acceptable for clinical decision-making when corrected for outliers. Pressure developed by the diaphragm in our patients appears within physiological limits.