Lluis Blanch M.D.Consultant, Critical Care Center, Hospital of Sabadell

Scientific Director, Corporacio Parc TauliUniversity Institut Fundació Parc Taulí

Universitat Autónoma de BarcelonaSabadell, Spain

lblanch@tauli.cat

Cairo, February 6 - 7, 2008

Pressure – Volume Curves in ARDS: Are they Useful ?

88thth PulmonaryPulmonary Medicine Medicine UpdateUpdate CourseCourseTheThe EgyptianEgyptian SocietySociety ofof ICM & Trauma ICM & Trauma

Albaiceta GM, Blanch L, Lucangelo U. Current Opinion in Crtical Care 2008;14:80-86

Human ARDS

AssessmentAssessment ofof PulmonaryPulmonary MorphologyMorphology in ALIin ALISignificanceSignificance ofof LowerLower InflectionInflection PointPoint in in thethe PP--V CurveV Curve

Vieira et al. Am J Resp Crit Care Med 1999; 159:1612-1623.

Overdistension

LIP + 2 cmHLIP + 2 cmH22OO LIP + 7 cmHLIP + 7 cmH22OOZEEPZEEP

AssessmentAssessment ofof PulmonaryPulmonary MorphologyMorphology in ALIin ALIAbsenceAbsence ofof LowerLower InflectionInflection PointPoint in in thethe PP--V CurveV Curve

Vieira et al. Am J Resp Crit Care Med 1999; 159:1612-1623.

Overdistension

PEEP 10 cmHPEEP 10 cmH22OO PEEP 15 cmHPEEP 15 cmH22OOZEEPZEEP

Current Opinion in Critical Care 2007;13:332-337

Alveolar Recruitment with PEEP Alveolar Overdistension with PEEP

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MaggioreMaggiore S et al. AJRCCM 2001; 164: 795S et al. AJRCCM 2001; 164: 795--801801

Assessment of alveolar derecruitment by computed tomography(left panel) and pressure-volume curves (right panel).

Comparison of alveolar derecruitment assessed by the computedtomography and pressure–volume curve methods.

Crit Care Med 2003;31:2514-19

Crit Care Med 2003;31:2514-19

P-V Maneuver Using the Constant Low-Flow Method

Current Opinion in Critical Care 2008;14:80-86

VT

autoPEEP PEEP

COPD + Pneumoniaafter intubation

VT

PEEP

Obese patientStroke + Moderate ALI

Frequency distribution of 197 discrete measurementsof lower inflection point (LIP) from 16 clinical studies

Respir Care • April 2007 Vol 52 No 4

Am J Resp Crit Care Med 1997;156:846-854

Roupie E et al. Am J Respir Crit Care Med 1995;152:121.

The Effects of Changing VT in Patients with ARDS

Pulmonary cytokines were lower in the “more protected”than in the “less protected” (P < 0.05). Ventilator free days

were 7 ± 8 and 1 ± 2 in the “more protected” and “lessprotected”, respectively (P = 0.01). Plateau pressure in

“more protected” ranged between 25 and 26 cmH2O and in “less protected” between 28 and 30 cmH2O (P = 0.006).

30 ARDS pts. Ventilated accordingthe “ARDSnet Strategy”

30 min.period

EffectEffect ofof MechanicalMechanical VentilationVentilation ononInflammatoryInflammatory MediatorsMediators in in PatientsPatients withwithARDS. A ARDS. A RandomizedRandomized ControlledControlled TrialTrial. .

RanieriRanieri VM et al. JAMA 1999; 282: 54VM et al. JAMA 1999; 282: 54--6161

Control Control GroupGroup: VT 11 : VT 11 mlml//kgkg, PEEP 6.5 , PEEP 6.5 cmHcmH22OOLungLung ProtectiveProtective GroupGroup: VT 7.5, PEEP 14.8 : VT 7.5, PEEP 14.8 cmHcmH22OO

Design:RCT severe ARDS PaO2/FiO2 < 200 mmHgHigh PEEP & Low VT versus Low PEEP & Moderate VTControl Group: VT 9-11 ml/kg PBW & PEEP > 5 cmH2OTreat. Group: VT 5-8 ml/kg PBW & PEEP Pflex + 2 cmH2OOutcome:Control n=45. Mortality 53.3%Treatment n=50. Mortality 32%

p = 0.04

Crit Care Med 2006;34:1311-8

1. Easy & safe at the bedside2. LIP may be beginning of substantial recruitment3. Absence of LIP: focus on UIP4. When LIP and UIP appears in the P-V curve regional mechanical differences are less important5. Impaired chest wall mechanics is problematic 6. Outcome can be optimized using P-V curves

Useful Clinical Information from P/V Curves