Monitoring Muscle (Diaphragm) Thickness Ewan C. Goligher MD Mount Sinai Hospital, Toronto, Canada Department of Physiology, University of Toronto
Disclosures Conflicts of Interest Equipment from Sonosite Equipment and research support from GE
Is the Diaphragm Worth Monitoring? VILI? Weaning Survival & Long-term Outcomes Hemodynamics ICU Readmission
Anatomy of the Diaphragm
Action of the Diaphragm De Troyer and Loring, Handbook of Physiology
Action of the Diaphragm De Troyer and Loring, Handbook of Physiology
Inspiratory Diaphragm Thickening Wait JL et al J Appl Phys 1997 Cohn et al J Appl Phys 1997
Conclusions Conclusions Imaging Diaphragm Thickness Cur r en t Concept s Zoneof ApositionUltrasound! Zoneof ApositionUltrasound! A A B B Pleura Pleura Chest Chest Wall Wall Normal Diaphragm Diaphragm Diaphragm D Peritoneum Peritoneum B-mode! B-mode! Lung M-m Lung A Experimental SetupandInspiratoryManeuvers! Experimental SetupandInspiratoryManeuvers! P ga! PEA ga! di! EA P es! di! PSpirometer! es! Paralyzed C C Liver Tidal breathing! Tidal breathing! Threshold-loaded breathing(20cmh Threshold-loaded 2 O)! breathing(20cmh Pleura 2 O)! Liver D D Maximal inspiratory transdiaphragmatic Maximal inspira presureefort! transdiaphragm presureefo Chest Wall
Imaging Diaphragm Thickness ionultrasound! A B Pleura Chest Wall Normal iaphragm Diaphragm Diaphragm Peritoneum B-mode! Lung M-mode! tupandinspiratorymaneuvers! Paralyzed iaphragm C Tidal breathing! Threshold-loaded breathing(20cmh 2 O)! Pleura Liver D Tdi = A Liver Rest @FRC! Maximal inspiratory transdiaphragmatic Inhaletotarget! TF = (B A)/A * 100% Chest Wall presureefort! 25%IC! 50%IC! 75%IC! IC! Pleura Relax&hold@target!
Metrology: Diaphragm Thickness Cohn JAP 1997
Metrology: Diaphragm Thickness Values in Healthy Subjects Reproducibility ltrasound! A Pleura m Chest Wall Diaphragm 1.5-5.0 mm B Diaphragm Repeat (same obs) +/- 0.4 mm (R) +/- 1.9 mm (L) Site Marked +/- 0.2 mm (R) d m Peritoneum C Liver D Lung Repeat Liver (diff obs) Tidal breathing! Rest @FRC! Maximal inspiratory Threshold-loaded transdiaphragmatic Inhaletotarget! breathing(20cmh 2 O)! Chest Wall presureefort! 25%IC! 50%IC! 75%IC! IC! Pleura Pleura Relax&hold@target! Boon et al Muscle Nerve 2013 Goligher et al. Intensive Care Med 2015 ragm B-mode! andinspiratorymaneuvers! M-mode! Diaphragm +/- 2.1 mm (R) +/- 1.4 mm (L) Site Marked +/- 0.4 mm (R)
Metrology: Diaphragm Thickening Viver et al. ICM 2012 Goligher et al. ICM 2015
Metrology: Diaphragm Thickening Values in Healthy Subjects Reproducibility 25-45% @ rest Repeat (same obs) +/- 19% (R) +/- 13% (L) Site Marked +/- 17% (R) Diaphragm M-mode! >20% @ maximal Inspiratory effort Repeat (diff obs) +/- 27% (R) +/- 39% (L) Site Marked +/- 16% (R) Liver Rest @FRC!
Metrology: Diaphragm Thickening Gottesman et al JAP 1997
Thickening: Volume vs Pressure? End-inspiratory hold Peak inspiration End-expiration B/A C/A
Thickening vs Excursion Thickening Fraction Excursion Unpublished observations
Sources of Error Thickness Variability in diaphragm thickness across its surface Body habitus Changes in muscle echogenicity during MV Left side Failure to mark site Thickening Combines error of two thickness measurments Function Variability in volitional inspiratory effort
Clinical Insights 1: Inspiratory Effort During MV Goligher et al. Intensive Care Med 2015
Clinical Insights 2: Evolution of Diaphragm Thickness During MV +30% Change in diaphragm thickness over time (% of baseline) +20% +10% 0% -10% -20% 47 13 47 13 44 47 11 32 41 11 28 39 11 22 34 10 11 11 18 15 13 30 21 27 Group: Diaphragm Thickness Change >10% loss on or before day 8 <10% change on or before day 8 >10% gain on or before day 8-30% 1 2 3 4 5 6 7 8 Day of Study Goligher et al AJRCCM 2015
Clinical Insights 3: Inspiratory Effort Matters Change in Diaphragm Thickness Over Time (% of Baseline) +10% 0% -10% -20% 0 2 Duration of Ventilation (Days) 4 6 8 0% 20% 40% 60% 80% Diaphragm Contractile Act ivity (Tidal Thicke ning Fraction) Goligher et al AJRCCM 2015
Clinical Insights 4: Predicting Successful Extubation DiNino et al Thorax 2014
Summary: Monitoring Diaphragm Thickness Valid and reproducible measurements Right hemidiaphragm Mark site for repeated measurements Permits evaluation of: Structural changes (thickness, echogenicity) Inspiratory effort (thickening fraction) Muscle function (maximal thickening fraction) Yields important insights for clinical management Potential intervention and/or outcome in future studies
Acknowledgments Mentorship Dr. Niall Ferguson Dr. Laurent Brochard Dr. Brian Kavanagh Dr. Gordon Rubenfeld Dr. Steffen-Sebastian Bolz Collaborators Dr. Michael Detsky Alistair Murray Debbie Brace Stefannie Vorona Ashley Lanys Dr. Nuttapol Rittayamai Dr. Michael Sklar ewan.goligher@mail.utoronto.ca
Questions? ewan.goligher@mail.utoronto.ca