Pressure-Volume Curves in ARDS:Are they Useful?

8th Pulmonary Medicine Update Course 2008 presentation by Dr.Lluis Blanch, Spain.
Scribe Knowledge Resources(www.scribeofegypt.com)

1. LluisBlanchM.D.
Consultant, CriticalCareCenter, Hospital ofSabadell
ScientificDirector, CorporacioParcTauli
UniversityInstitutFundacióParcTaulí
UniversitatAutónoma de Barcelona
Sabadell, Spain
[email protected]
Cairo, February6 -7, 2008
Pressure–VolumeCurves in
ARDS: Are theyUseful?
88
thth
Pulmonary Pulmonary
Medicine Medicine
Update Update
Course Course
TheThe
Egyptian Egyptian
Society Society
ofof
ICM & Trauma ICM & Trauma

2. AlbaicetaGM, BlanchL, LucangeloU. CurrentOpinionin CrticalCare2008;14:80-86
Human ARDS

3. Assessment Assessment
ofof
Pulmonary Pulmonary
Morphology Morphology
in ALI in ALI
Significance Significance
ofof
Lower Lower
Inflection Inflection
Point Point
in in
thethe
PP
--
V Curve V Curve
Vieira et al. AmJ RespCritCareMed1999; 159:1612-1623.
Overdistension
LIP + 2 cmH LIP + 2 cmH
22
OO
LIP + 7 cmH LIP + 7 cmH
22
OO
ZEEP ZEEP

4. Assessment Assessment
ofof
Pulmonary Pulmonary
Morphology Morphology
in ALI in ALI
Absence Absence
ofof
Lower Lower
Inflection Inflection
Point Point
in in
thethe
PP
--
V Curve V Curve
Vieira et al. AmJ RespCritCareMed1999; 159:1612-1623.
Overdistension
PEEP 10 cmH PEEP 10 cmH
22
OO
PEEP 15 cmH PEEP 15 cmH
22
OO
ZEEP ZEEP

5. CurrentOpinionin CriticalCare2007;13:332-337
Alveolar RecruitmentwithPEEP
Alveolar OverdistensionwithPEEP

6. Pt # 1
0
300
600
900
1200
1500
1800
2100
01020304050
Pel (cm H
2
O)
Volume (mL)
Pt # 17
0
300
600
900
1200
1500
1800
2100
01020304050
Pel (cm H
2
O)
Volume (mL)
Pt # 14
0
300
600
900
1200
1500
1800
2100
01020304050
Pel (cm H
2
O)
Volume (mL)
Pt # 4
0
300
600
900
1200
1500
1800
2100
01020304050
Pel (cm H
2
O)
Volume (mL)
Maggiore Maggiore
S et al. AJRCCM 2001; 164: 795 S et al. AJRCCM 2001; 164: 795
--
801801

7. Assessmentofalveolar derecruitmentby computedtomography
(leftpanel) andpressure-volumecurves (rightpanel).

8. Comparisonofalveolar derecruitmentassessedby thecomputed
tomographyandpressure–volumecurve methods.

9. CritCareMed2003;31:2514-19

10. CritCareMed2003;31:2514-19

11. P-V ManeuverUsingtheConstantLow-FlowMethod
CurrentOpinionin CriticalCare2008;14:80-86

12. VT
autoPEEP
PEEP
COPD + Pneumonia
afterintubation

13. VT
PEEP
Obesepatient
Stroke+ ModerateALI

14. Frequencydistributionof197 discretemeasurements
oflowerinflectionpoint(LIP) from16 clinicalstudies
RespirCare•April2007 Vol52 No 4

15. Am J Resp Crit Care Med1997;156:846-854

16. RoupieE et al. AmJ RespirCritCareMed1995;152:121.
TheEffectsofChangingVT in PatientswithARDS

17. Pulmonarycytokineswerelowerin the“more protected”
thanin the“lessprotected”(P < 0.05). Ventilatorfree days
were7 ±8 and1 ±2 in the“more protected”and“less
protected”, respectively(P = 0.01). Plateaupressurein
“more protected”rangedbetween25 and26 cmH
2
Oandin
“lessprotected”between28 and30 cmH
2
O(P = 0.006).
30 ARDS pts. Ventilatedaccording
the“ARDSnetStrategy”

18. 30 min.period

19. Effect Effect
ofof
Mechanical Mechanical
Ventilation Ventilation
onon
Inflammatory Inflammatory
Mediators Mediators
in in
Patients Patients
withwith
ARDS. A ARDS. A
Randomized Randomized
Controlled Controlled
Trial Trial
. .
Ranieri Ranieri
VM et al. JAMA 1999; 282: 54 VM et al. JAMA 1999; 282: 54
--
6161
Control Control
Group Group
: VT 11 : VT 11
mlml
//
kgkg
, PEEP 6.5 , PEEP 6.5
cmHcmH
22
OO
Lung Lung
Protective Protective
Group Group
: VT 7.5, PEEP 14.8 : VT 7.5, PEEP 14.8
cmHcmH
22
OO

20. Design: RCT severeARDS PaO
2
/FiO
2
< 200 mmHg
HighPEEP & LowVT versus LowPEEP & ModerateVT
Control Group: VT 9-11 ml/kgPBW & PEEP > 5 cmH
2
O
Treat. Group: VT 5-8 ml/kgPBW & PEEP Pflex+ 2 cmH
2
O
Outcome: Control n=45. Mortality53.3%
Treatmentn=50. Mortality32%
p = 0.04 CritCareMed2006;34:1311-8

21. 1.
Easy & safe at the bedside
2.
LIP may be beginning of substantial
recruitment
3.
Absence of LIP: focus on UIP
4.
When LIP and UIP appears in the P-V curve
regional mechanical differences are less
important
5.
Impaired chest wall mechanics is problematic
6.
Outcome can be optimized using P-V curves
Useful Clinical Information from P/V Curves