This document discusses pulmonary recruitment in ARDS patients and strategies for lung protection during mechanical ventilation. It describes how recruitment maneuvers using high airway pressures can reopen collapsed alveoli, preventing ventilator-induced lung injury from repeated opening and closing. The optimal settings for recruitment maneuvers and PEEP levels depend on a patient's recruitability, assessed via low-flow pressure-volume curves. PEEP levels are best guided by esophageal manometry or oxygen saturation to maintain alveolar stability and oxygenation without overdistension.

1. PV curve and lung recruitmentDr Jean-Michel ArnalIntensive Care Unit. Hôpital Font PréToulon Francejean-michel@arnal.org

2. Mechanisms of Ventilator Induced Lung InjuriesMechanical InjuryBarotrauma and/or volutraumaresulting from lung overdistension Atelectraumaresulting from repeated alveolar recruitment/ derecruitmentInflammatory InjuryBiotrauma: alveolar inflammation

3. Prevention of VILIReduced tidal volume and airway pressure limitation strategyRecruitment strategy: recruitment maneuver + PEEP to avoid derecruitment

4. What do we know about ARDS?Lower tidal volume and airway pressure limitation decreases mortalityNo effect of PEEP on mortalityARDS network. N Engl J Med 2000ALVEOLI. Brower. N Engl J Med 2004EXPRESS. Mercat JAMA 2008LOVS. Meade. JAMA 2008

5. Effect of PEEP on mortality in ARDSBriel. JAMA 2010

6. What do we know about PEEP?PEEP does not recruitCollapse / re-expansion occurs during tidal volumeRecruitment of previously collapsed lung with a recruitment maneuverPEEP may avoid collapse and derecruitment in a lung previously expanded/recruited

7. RecruitmentCollapsed compliant airways/ alveoliFluid occlusion of non collapsed airways

8. Am J Respir Crit Care Med 2006

9. 24 sur 26 patientsAm J Respir Crit Care Med 2006

10. n = 68

11. Recruitability depends onType of ARDSTime from the beginning of the diseasePressureChest wall compliance

12. Type of ARDSMechanism: extra pulmonary > pulmonaryLocalization: diffuse > lobarRiva. Crit Care Med 2008Puybasset. Intensive Care Med 2000

13. Time from the beginning of the diseaseEarly phaseProtein rich edema fluids and polyneutrophilsLate phaseFibrosing alveolitis

14. Pressure24 on 26 patientsBorges. Am J Resp Crit Care Med 2006

15. Chest wall compliance

16. Chest wall complianceAirway pressure is a rough estimate of transpulmonary pressureTalmor. Crit Care Med 2006

17. Assessment of recruitabilityEarly in the management of ARDSWhen hemodynamic condition is controlledLow flow inflation and deflation PV curve from 0 to 40 cmH2O

18. Assessment of recruitability

19. Assessment of recruitabilityShape of the curveGrasso. AJRCCM 2005

20. Assessment of recruitabilityLinear complianceMaggiore. AJRCCM 2001

21. Assessment of recruitabilityLinear complianceCLIN = 37 mL/cmH2OCLIN = 83 mL/cmH2O

22. Assessment of recruitabilityHysteresisDemory.Intensive Care Med 2008

23. Assessment of recruitabilityHysteresis6 798 cmH2O.ml25 115 cmH2O.mlDemory. Intensive Care Med 2008

24. Assessment of recruitabilityHysteresis and volume difference at 20 cmH2Or2 = 0.97Demory.Intensive Care Med 2008

25. Decision at the bedside

26. Decision at the bedsideNo recruitment maneuverLow PEEP: 5 – 10 cmH2ORecruitment maneuverHigh PEEP: > 10 cmH2O

27. Definition of a recruitment maneuverUse of a transient increase in transpulmonary pressure to reopen previously collapsed or non aerated lung units.

28. Volume recruited depends onPrevious recruitmentTranspulmonary inflation pressureDurationPEEP setting after the RM

29. Pressure and timeAlbert.J Appl Physiol 2009

30. Time = 2,6 sRothen.BJA 199912 anaesthetized patients with healthy lung

31. Optimal duration of the recruitment maneuver = 2,3 ± 1,3 sn = 50Arnal. Intensive Care Med [submitted]

32. Optimal duration of the recruitment maneuver**Recruitment maneuvern = 50Arnal. Intensive Care Med [submitted]

33. Recruitment maneuver at the bedsideConditionsPassive patient: deep sedation ± paralysisStable hemodynamic condition: ΔPP < 13%Cuff over inflated to avoid leaksNo contraindications

34. Recruitment maneuver at the bedsideContraindicationsHigh intracranial pressureEmphysemaBronchopleural fistulaPregnancyRight heart failure

35. Recruitment maneuver at the bedsideSettings

36. Volume increase during a recruitment maneuverVRM= 100 mLVRM= 240 mL

37. How to set PEEP after recruitment maneuver?Low inflection point on PV curveDeflection point on PV curveMaximum PEEP while limiting Pplat around 28 cmH2OPEEP setting guided by esophageal measurementPEEP setting guided by SpO2Hickling. AJRCCM 1998Hickling. AJRCCM 2001EXPRESS. Mercat JAMA 2008Talmor. N Engl J Med 2009Lapinski. Intensive Care Med 1999

38. PEEP setting guided by esophageal pressureRandomized controlled trial61 ARDS patientsControl: ARDSnet PEEP/FiO2 tableIntervention: PEEP end-expiration Ppulm 0 - 10 cmH2OTalmor. N Engl J Med 2009

39. PEEP setting guided by esophageal pressureVT = 400PEEP= 12FiO2= 60%Ppulmins= 3Ppulmexp= -6Talmor. N Engl J Med 2009

40. PEEP setting guided by esophageal pressureVT = 320PEEP= 24FiO2= 60%Ppulmins= 12Ppulmexp= 4Talmor. N Engl J Med 2009

41. PEEP setting guided by esophageal pressureTalmor. N Engl J Med 2009

42. PEEP setting guided by esophageal pressureTalmor. N Engl J Med 2009

43. PEEP setting guided by esophageal pressureTalmor. N Engl J Med 2009

44. PEEP setting guided by esophageal pressure65 years old woman, BMI = 32Community acquired pneumonia

45. PEEP setting guided by SpO2n = 14Lapinski. Intensive Care Med 1999

46. PEEP setting guided by SpO2Lapinski. Intensive Care Med 1999

47. Conclusions Recruitment strategy is part of protective ventilation in ARDS

48. PEEP does not recruit

49. Assessing recruitability is a pre-requisite for a rational setting of PEEP: low flow PV tool

50. High potential of recruitability patients: Recruitment strategy

51. Recruitment maneuver: 40 cmH2O (up to 60) for 10s

52. PEEP > 10 cmH20 (up to 25) guided by SpO2

53. Recruitment should be an early goal in the management of ARDS.Thank you…