driving pressure: value and limitations -...
TRANSCRIPT
![Page 1: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/1.jpg)
Driving Pressure: Value and Limitations
John J. Marini
University of Minnesota
Minneapolis / St. Paul (USA)
![Page 2: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/2.jpg)
Driving Pressure Correlates Well With Mortality Risk
Amato et al NEJM 2015
![Page 3: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/3.jpg)
Re-Focusing on Airway Driving Pressure Enthusiasm With a Note of Caution
• Definition of Driving Pressure
• Why should we pay attention?
• Why should we be cautious?
![Page 4: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/4.jpg)
Driving Pressure Definitions
• PPLAT – PEEP
• Ratio of tidal volume to compliance (VT/C)
VT normalized to capacity of ‘baby lung’
DP
Tidal Volume
Plateau Pressure
Compliance
PEEP
![Page 5: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/5.jpg)
Driving Pressure Definitions
• PPLAT – PEEP
PPLAT – (PEEP+Auto-PEEP)
• Ratio of tidal volume to compliance (VT/C)
Respiratory system compliance
Lung compliance
Regional DP’s vary DP
Tidal Volume
Plateau Pressure
Compliance
PEEP
![Page 6: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/6.jpg)
Driving Pressure is a Static Parameter in a Dynamic Environment
DP Assumes Passive Conditions
Auto-PEEP Total
![Page 7: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/7.jpg)
Indicator of Severity
Driver of Injury
How Should We Regard Driving Pressure?
![Page 8: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/8.jpg)
Why Should We Pay Attention?
• Parameter for Disease Progression or Resolution in the individual patient
• Indicator for ‘Best PEEP’
• Key Component of VILI Causation?
• Target for Adjusting Ventilator Settings?
![Page 9: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/9.jpg)
Driving Pressure May Help Select Best PEEP
Suter NEJM 1975
Tidal mechanics have disappeared from the ARDS criteria…
Constant VT
![Page 10: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/10.jpg)
Why Should We Pay Attention?
• Parameter for Disease Progression or Resolution in the individual patient
• Indicator for ‘Best PEEP’
• Key Component of VILI Causation?
• Target for Adjusting Ventilator Settings?
![Page 11: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/11.jpg)
“Stretch”
“Shear”
Airway Trauma
How Could Driving Pressure Mediate Airspace Injury?
![Page 12: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/12.jpg)
PEEP
Alveolar Pressure
Less Driving Pressure
Shorter Lever Arm
Fewer Units
at Risk
Mechanical Stressors
Assumes Passive Inflation & Normal Chest Wall
![Page 13: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/13.jpg)
20
40
60
80
100
Pressure [cmH2O] 10 20 30 40 60 50
To
tal L
un
g C
apac
ity
[%]
R = 22%
R = 81%
R = 100%
R = 93%
0
0
R = 0%
R = 59%
From Pelosi et al
AJRCCM 2001
There are ‘high risk’
junctions at every volume
Is a Given Driving Pressure Safe or Dangerous? It could depend on the plateau & recruitability
Lower Plateau
More Collapse
Higher Plateau
Less Collapse
![Page 14: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/14.jpg)
Air
way P
ressu
re (
cm
H2O
)
10
20
30
40
50 Junctional Lung Units and Risk of VILI
![Page 15: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/15.jpg)
PEEP
![Page 16: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/16.jpg)
PEEP
Is a Given Driving Pressure Safe (or Not) at Every PEEP?
![Page 17: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/17.jpg)
Why Should We Pay Attention?
• Parameter for Disease Progression or Resolution in the Individual Patient
• Indicator for ‘Best PEEP’
• Insights to VILI Causation
• Target for Adjusting Ventilator Settings?
![Page 18: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/18.jpg)
Why Should We Be Cautious?
• Better predictor than VT or PPlateau alone • May overestimate risk to the lung • May underestimate risk
– during effort – Zero flow versus plateau
• Is not the only contributor to VILI – Cycling frequency – Flow amplitude and profile – Mechanical heterogeneity
![Page 19: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/19.jpg)
Trans-Pulmonary Driving Pressure
![Page 20: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/20.jpg)
The Chest Wall May Distort Airway
Pressure Readings
![Page 21: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/21.jpg)
ARDS Chest Wall is Often NOT Normal
![Page 22: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/22.jpg)
Global Airway Driving Pressure Increases
During Proning But VILI Declines
Global Injury
Regional Injury
![Page 23: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/23.jpg)
Abdominal Hypertension Increases Calculated Driving Pressure
Cortes GA, Marini JJ; 2013
Constant Tidal Volume
![Page 24: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/24.jpg)
Ratios of Transpulmonary and Airway Driving Pressures At Two Levels of Abdominal Pressure
Cortes-Puentes et al, Crit Care Med 2015
![Page 25: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/25.jpg)
Vertical Gradient of Driving Pressures
![Page 26: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/26.jpg)
Why Should We Be Cautious?
• Better predictor than VT or PPlateau alone • May overestimate risk to the lung • May underestimate risk
– Zero flow pressure versus plateau pressure – During effort
• Is not the only contributor to VILI – Cycling frequency – Flow amplitude and profile – Mechanical heterogeneity
![Page 27: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/27.jpg)
Zero Flow Point > Pplat
Driving
Pressure
![Page 28: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/28.jpg)
⏎
![Page 29: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/29.jpg)
Vigorous Breathing Violates Objectives of Lung Protection
Stiff Chest Wall Or Expiratory Effort
Consider BOTH phases of the cycle!
![Page 30: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/30.jpg)
High Driving Pressures Occur Normally Occur
During Vigorous Exercise PTP correlates with minute ventilation
Normal Subjects on Treadmill
42 +/- 16 cmH2O
![Page 31: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/31.jpg)
Expiratory Muscle Activity May Contribute to VILI
Control Abd Effort Paralysis
![Page 32: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/32.jpg)
Why Should We Be Cautious?
• Better predictor than VT or PPlateau alone • May overestimate risk to the lung • May underestimate risk
– During effort – Zero flow versus plateau
• Is not the only contributor to VILI – Cycling frequency – Flow amplitude and profile – Mechanical heterogeneity
![Page 33: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/33.jpg)
Injurious Driving Power ‘Ergo-trauma’
Int Care Med September 2016
![Page 34: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/34.jpg)
Pressure
Vo
lum
e
PEEP1 PEEP2
Machine Work During Inflation
PEEP Increases Machine
Work, But Stores Until
Potential Energy is Released
In Exhalation.
Int Care Med September 2016
![Page 35: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/35.jpg)
Pressure
Vo
lum
e
PEEP1 PEEP2
Non-Resistive Work Per Cycle
Int Care Med September 2016
![Page 36: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/36.jpg)
Vo
lum
e
Pressure
DP 1
DP 2
PEEP
Non-Resistive Power At Two Driving Pressures
Int Care Med September 2016
![Page 37: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/37.jpg)
Injurious Driving Power ‘Ergotrauma’
• Power = Energy per cycle x Frequency
• Relevant component of power is the product of driving pressure and minute ventilation
– Ptot = Pres + DP + PEEP
– Product of DP and VE is dynamic parenchymal component of power--- The Driving Power
• Normalize for capacity of smaller ‘Baby Lung’
– Stress Intensity = [DP x VE] / 10 C
Int Care Med September 2016
![Page 38: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/38.jpg)
Vo
lum
e
Pressure
Unrecovered (Absorbed) Energy
Int Care Med September 2016
![Page 39: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/39.jpg)
Unrecovered Energy Load
• Surface forces
• Disruption and displacement of liquid bridges
• Rearrangement of connective tissues
• Etc.
![Page 40: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/40.jpg)
Is VILI Caused By Unrecovered Work During The Inflation Cycle?
“Str
ain”
“Stress”
Tension
Len
gth
DP2
DP1
![Page 41: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/41.jpg)
Don’t Forget the VE & the Vascular Side! Identical Driving Pressures but Different Damage
![Page 42: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/42.jpg)
Three Flow Options for Tidal Volume Delivery
Same Tidal Volume and I:E Ratio
![Page 43: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/43.jpg)
Differing Inspiratory Flows & Injuries Identical Airway Driving Pressures
Maeda Anesthesiology 2004
Stress index positive
![Page 44: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/44.jpg)
How Fast Strain and Driving Pressure Are Applied are Important Especially at High Stretch
Protti et al Crit Care Med 2016
![Page 45: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/45.jpg)
Trajectory of DP May Be Important
Protti et al Crit Care Med 2016 (in press)
![Page 46: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/46.jpg)
Stress Focusing Amplifies Effect Of Global Airway Driving Pressure
![Page 47: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/47.jpg)
min max
Stress is amplified in high stiffness zones
Mead J et al. J. Appl. Physiol. 28(5):596-608 1970
![Page 48: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/48.jpg)
Can Driving Pressure Predict VILI Risk?
• Better predictor than VT or PPlateau alone • Not the only contributor to VILI
– Amplified junctional forces – Tidal opening & closure – Frequency & minute ventilation – Inspiratory flow and flow profile – Vascular pressures & flows
• May overestimate risk – Stiff chest wall – Unmeasured auto-PEEP
• May underestimate risk – P1 vs. Plateau
– Spontaneous breathing efforts
Dynamics of energy delivery
![Page 49: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/49.jpg)
…But Maybe Not Quite Everything We Need!
DP is a Conceptual
Step Forward…
![Page 50: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/50.jpg)
END
![Page 51: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/51.jpg)
![Page 52: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/52.jpg)
Static and Dynamic Driving Pressures
Passive Inflation
Auto-PEEP Total
![Page 53: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/53.jpg)
Is VILI Caused By Unrecovered Work During The Inflation Cycle?
“Str
ain”
“Stress”
Tension
Len
gth
DP2
DP1
![Page 54: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/54.jpg)
My Respectfully Cautious View Of Airway Driving Pressure
John J. Marini
University of Minnesota
Minneapolis / St. Paul (USA)
![Page 55: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/55.jpg)
Strain (dVgas/Vgas0)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Str
ess
(PL
, cm
H2
O)
0
5
10
15
20
25
30
35
40
45
50
55
Extreme Strain is Dangerous but….
Protti A. et al. Am J Respir Crit Care Med. 2011 Feb 4.
Driving Pressure Parallels
Stress & Strain
![Page 56: Driving Pressure: Value and Limitations - MSICmsic.org.my/sfnag402ndfbqzxn33084mn90a78aas0s9g/asmic2016_JohnMarini1.pdfDriving Pressure: Value and Limitations John J. Marini University](https://reader031.vdocuments.mx/reader031/viewer/2022021917/5e48b53b2dbfec5583319519/html5/thumbnails/56.jpg)
Recruitability as well as Alveolar Strain Are Important Contributors to Mortality Risk
ARDS N=68