1. Mechanical Ventilation PV Curves

2. Techniques for Measurement 1. Supersyringe 2. Constant Flow 3. Multiple Occlusion

3. Low Constant Flow Simple Can be performed on ventilator (some types) Avoids disconnect Hysteresis Heavy sedation or paralysis required Flow  9 L/min for “quasi-static” conditions 1 1 Qin Lu, AJRCCM 1999;159:275-282 Servillo, AJRCCM 1997;155:1629-1636

4. Radford, Tissue Elasticity, 1957 Surface forces due to air-liquid interface

5. Gattinoni, ARRD 1987;136:730-736 Pflex

6. P "safe" window zone of overdistension V Pressure-Volume Curve LIP UIP zone of derecruitment and atelectasis

7. PV Curve Normal ARDS COPD

8. Normal

9. ARDS

10. P "safe" window zone of overdistension V atelectrauma volutrauma Lung Protective Ventilator Strategies LIP UIP zone of derecruitment and atelectasis DON’T EVEN THINK OF PARKING HERE

11. Pressure Volume Safe zone Overdistention Derecruited Lower P flex, LIP Upper P flex, UIP PV Curve in ARDS

12. Preventing Overdistention and Under-Recruitment Injury “Lung Protective” Ventilation VOLUMEVOLUME VOLUMEVOLUME Pressure Limit Distending Pressure Add PEEP Limit VT

13. PV Curve COPD