Recruitment Maneuvers in ARDS Dr Chennamchetty

Recruitment Maneuvers

Dr. Vijay Kumar Chennamchetty

Case Scenario

A 23yr female student by occupation presented with febrile illness of 4days, h/o sore throat, cough present, no h/o travel, h/o breathlessness 1day

o/eSensorium normal Lungs: rr-40/mt, Spo2: 55% on NRBM Hemodynamics: stable ABG: type 1 resp failure (po2=25)

Intubated in EMR & shifted to CCU

Case Scenario


Introduction Definition Physiological Rationale Recruitment Maneuvers (RM’s) Monitoring The Efficacy Factors Influencing The Response Clinical Trials Limitations

Introduction

Mechanical Ventilation as an essential supportive measure

“Lung protective” approach Drawback

The ARDS Network. NEJM 2000; 342:1301-08

Gajic et al VALI in pt’s with no lung ALI . CCM 2004; 32:1817-24


IntroductionDefinition

Definition

Recruitment:“ aeration of un-aerated alveoli”

Recruitment Maneuver / Re-expansion Maneuver:

“ denotes the dynamic process of an intentional transient increase in trans pulmonary pressure aimed at opening unstable airless alveoli leading to increase in EELV, even if it is inadequate to result in effective alveolar recruitment ”

Pelosi et al,Review article

Critical Care 2010; p1 - 7


IntroductionDefinitionPhysiological Rationale

ARDS: Physiological Rationale

Baby lung1. Normal

2. Partly aerated

3. Collapsed 1. Lung protection2. Alveolar stabilization3. Alveolar recruitment

Gattinoni et al. Intens Care Med. 1986; 12: 137-42

Physiological Rationale

Atelectasis in normal lungs Absorption atelectasis Surfactant depletion “Lung protective strategy” RACE - Biotrauma

Froesse JC Anesthesiology 1974; 41:242-55

Maggiore et al AJRCCM 2003;

167:1215-24

Ranieri et al A RCT JAMA 1999;

282:54 - 61

Over-distension

Atelectasis

End-Expiration

Tidal Forces (Transpulmonary and Microvascular

Pressures)

Extreme Stress/Strain

Moderate Stress/Strain

Mechano signaling viaintegrins, cytoskeleton, ion channels

inflammatory cascade

Cellular Infiltration and Systemic Inflammation

Rupture Signaling

Pathways to VILI

Marini / Gattinoni CCM 2004

Barotrauma

Volutrauma

BiotraumaStress @ interface

MODS Slutsky et al

Chest, 116 (1): 9s-16s

RACE

Opening and Closing Pressures50

Paw [cmH2O]0 5 10 15 20 25 30 35 40 45 50

0

10

20

30

40 Opening pressureClosing pressure

“High pressures may be needed to open some lung units, but once open, many units stay open at lower pressure”

%

Crotti et al AJRCCM 2001


IntroductionDefinitionPhysiological Rationale Indications

Who needs RM ………

ARDSHypoxic Post suctioningPost disconnection

Atelectasis related to GACardiogenic Pulmonary Edema

Lapinsky & Sangeeta Mehta

Critical Care 2005; 9:60 - 65


Introduction Definition Physiological Rationale Indications Types of Recruitment Maneuvers

Pre-requisites to perform RM

Arterial line Central line Deep Sedation / Paralysis Alarm settings


“Continuous inflation” technique

Anesthesiology 2002, 96:795–802.Curr Opin Crit Care 2003; 9:22–27

CPAP : 35-40 cm H20 for 30-40 seconds

Continuous Inflation Technique

CPAP 40cm for 40 secsPEEP set 2cm above LIP

Borges et al Critical Care

2002; 9:60 - 65

% Collapsed lung Recruitment Steps

63% 05%

Continuous Inflation Technique

Anesthesiology 2002, 96:795–802.Curr Opin Crit Care 2003; 9:22–27

PEEP + Peak pressure: up to 60 cmH2O


Anesthesiology 2002, 96:795–802.Curr Opin Crit Care 2003; 9:22–27Crit Care Med 2004; 32: 2371–77

Intermittent Sigh

Intermittent PEEP

Progressive PEEP

Slide Courtesy: Dr. Ram Echambadi Rajagopalan

Anatomical Recruitment

No recruitment PEEP + 5 40 cm recruitment + PEEP above LIP 60 cm recruitment PEEP + 25AJRCCM 2006;174: 268 – 78.

26 patients

Slide Courtesy: Dr. Ram Echambadi Rajagopalan


IntroductionDefinitionPhysiological Rationale IndicationsRecruitment ManeuversMonitoring The Efficacy

Monitoring The Efficacy

Malbouisson et alPEEP-RM / CT

AJRCCM 2001; 163:1444-50

Richard JC et alRole of PEEP & RM

AJRCCM 2001; 163:1609-13

Enrique & VilagraEffects of RM

CC Forum 2004; 8:115-121

ATS

loop C: Sustained inflation on high PEEP favored alveolar over-distension

Interpreting the PV Curve

Measurement is not practical clinically A single inflation probably does not provide useful information

to determine safe ventilator settings

Whole lung P/V curve is a composite of multiple regional P/V curves (LIP varies widely)

Kunst PW et al CCM 2000

PaO2 improves No change EVLW Decrease in

atelectasis rather than EVLW

Change in CI - Significant

Continuous Scvo2 Changes in CVP, HR

& MAP - insignificant

Tamas Leiner et al CCM 2007; Vol 35,

No.3

n = 18

Viviane R. S,MD ;et al

CCM 2010; Vol. 38, No 11

n = 36

40 cm/40secAnaesthesia, NMB& Protective Ventilation

ABG &Lung mechanics

ABG &Lung mechanics

After RM,Static lung elastance & alveolar collapse lung, liver, and kidney cell apoptosis, and type 3 pro-collagen and interleukin-6

mRNA expressionsElectron microscopic images of lung

parenchyma were assessed Alveolar edema is seen only in severe

ALI Alveolar collapse were similar in both

ALI groups

Viviane R. Santiago,MD ;et al

CCM 2010; Vol. 38, No 11

ConclusionsRM seems to promote modest but

consistent increasealveolar stress & inflammation fibrogenic responsesworsening lung function &potentiating injury to alveolar and kidney

epithelium lower in moderate ALI than in severe

ALI

IL-6

Type 3 Collagen


IntroductionDefinitionPhysiological Rationale IndicationsRecruitment ManeuversMonitoring The EfficacyFactors Influencing The Response

Factors Influencing The Response

Non uniformity & Variable outcomeUnderlying lung diseaseBaseline ventilation & volume historyDuration of IllnessProne positionType of RM & Post-recruitment PEEP

Underlying lung disease

Douglas R.Riva et alCCM 2008;

Vol.36 163:1900-08


AJRCCM 2001; 163:1444-50

“more effective at opening collapsed alveoli in extra-pulmonary ARDS, thus improving lung mechanics,

oxygenation, with limited damage to alveolar epithelium”

Underlying lung disease

Douglas R.Riva et alCCM 2008;

Vol.36 163:1900-08


AJRCCM 2001; 163:1444-50 “greater PCIII mRNA expression in ALI pulmonary”

RILI

Baseline ventilation & “Volume history”

Proportion of atelectatic lung Ventilatory settings that promote

derecruitment Volume history: time dependant

manner

Bates JH et alTime dependency; Theoritical model

Journal of Physiology 2002

Vander Kloot et alRM in oleic acid

injury modelAJRCCM 2000;

161:1949-56

Duration of Illness

“Less is More” & “More is Less” Less compliance of Lung & Chest

wall

Grasso S et alAnesthesiology

2002; 96: 795-802

Prone position

RM by itself “Mule” or Complimentory effect No incerase in EELV Makes lung expansion more uniform

by the attenuation of heterogeneous compressive forces

Pelosi et alAJRCCM

2003; 167: 521-527

RM type & Post-RM PEEP

Evidence little for type of RM Animal experiments Pressure targeted appears promising Post recruitment PEEP level – most

important determinant to prevent RACE

Lim et alCCM

2003; 167: 521-527


Introduction Definition Physiological Rationale Indications Recruitment Maneuvers Monitoring The Efficacy Factors Influencing The Response Clinical Trials

EXPRESS TRIALA RCT : JAMA 2008

768 patients, RCTMinimal distension:

PEEP & Plat : as low as possibleWithout affecting saturation targets

Increased Recruitment group:“PEEP titration based on Plateau”Oxygenation is not the goal

L. Brochard

EXPRESS TRIALA RCT : JAMA 2008

Conclusion:“strategy aimed at increased alveolar

recruitment while limiting hyperinflation didn’t significantly reduced mortality”

Better lung mechanics Reduced duration of MV Reduced duration of organ failure

Post hoc analysis: “ ALI may be associated with less benefits &

more adverse effects from high levels of PEEP”

L. Brochard

Lung Open Ventilation StudyJAMA 2008

985 pts enrolled, RCTControl group: protective ventilation

Volume Control Experimental group:

PC mode + RM (40/40) + Pplat 40 Tidal volumes were similar Mean PEEP : 10 Vs 15 in first 72hrs Barotrauma rates were similar

Lung Open Ventilation StudyJAMA 2008

Conclusion:“open strategy did appear to

improve secondary end points related to hypoxemia & use of rescue therapies”

Low rates of Refractory hypoxemia,Death with refractory hypoxemia &Need of “Rescue therapy”


Introduction Definition Physiological Rationale Indications Recruitment Maneuvers Monitoring The Efficacy Factors Influencing The Response Clinical Trials Limitations

Limitations

Brower, et al.: RMs in ALI

Review articleAJRCCM

2008; 176: 521-527

In a nut shell……….

Hemodynamic compromise Intracranial blood flowVILI / RILIBacterial translocationClinical benefits ????

Hemodynamic Effects

Lung inflation by positive pressure causes Increased pleural pressure and impeded venous return Increased pulmonary vascular resistance Compression of the inferior vena cava Retardation of heart rate increases

These effects are much less obvious in the presence of Adequate circulating volume Adequate vascular tone Spontaneous breathing efforts Preserved adrenergic responsiveness

“With More Lung Compliance, High Levels of PEEP are Generally Not Well Tolerated”

Hemodynamic Effects

Capillaries in the alveolar walls undergo compression even as interstitial vessels dilate. The net result is usually an increase in pulmonary vascular resistance, unless recruitment of collapsed units occurs.

Hemodynamic Effects

On Pulmonary vasculature:


IntroductionDefinitionPhysiological RationaleRecruitment ManeuversMonitoring The EfficacyFactors Influencing The ResponseLimitations Summary

Summary………..

Transient increase in trans pulmonary pressure to increase in EELV

“Lung protective strategy” Bio-trauma facilitates MODSARDS – commonest indicationPrerequisites CPAP – most widely studied & PEEP

titration in PC mode is user & hemodynamic friendly

Summary………..

Pao2 is a surrogate marker for monitoring Continuous Scvo2 & CCO monitor is

recommended as CVP is poor predictor of CI RM worsens the inflammation in Pulmonary ALI Volume history is important before attempting a

RM Prone has complimentary effect Titrate PEEP based on compliance &

oxygenation

Summary………..

Studies Did not reveal any mortality benefitsDid appear to improve secondary end points &

its role as rescue therapy

Adverse eventsHypotension & ArrhythmiasBarotraumas & De-saturation

Controversies

Which patients will benefit?How long to recruit?What is optimum level of Post

recruitment PEEP?When to use: routine or only during

hypoxic episodes?

Thank u so…… much

Diseased Lungs Do Not Fully Collapse,Despite Tension Pneumothorax

…and

They cannot always be fully “opened”

Dimensions of a fully Collapsed Normal Lung

Health & Medicine

Recruitment Maneuvers in ARDS Dr Chennamchetty