Il Reclutamento AlveolareGiuseppe Foti

Istituto di Anestesia e Rianimazione

Università di Milano-Bicocca dir. Prof. A. Pesenti

Ospedale S. Gerardo Monza

Reclutamento Alveolare:Reclutamento Alveolare:riapertura zone collassateriapertura zone collassate

PEEP 5 PEEP 10 PEEP 15

•E’ la PaOE’ la PaO22 il miglior indicatore di Rec ? il miglior indicatore di Rec ?•E’ la PEEP il maggior determinante del Rec ?E’ la PEEP il maggior determinante del Rec ?

PaO2 dipende non solo da quello che accade agli

alveoli…• Cardiac Output

• Emoglobina

• VO2

• pH, CO2

• Vasocostrizione Ipossica (per es: NO) etc…

Perché non misurare Perché non misurare Rec dal versante alveolare ? Rec dal versante alveolare ?

Chord Cpl Chord Cpl Alveolar recruitment Alveolar recruitment

Assumes that FRC immediately equalizesAssumes that FRC immediately equalizes coming from different PEEPcoming from different PEEP

Estimating Estimating ΔΔrec by P/V curve analysisrec by P/V curve analysis

FRC is different FRC is different coming from different Ventilatory SET UP !!coming from different Ventilatory SET UP !!

VrecVrec2020 (ml) (ml)

VrecVrec20,He20,He (ml) (ml)

-200-200

00

200200

400400

600600

800800

10001000

12001200

5 - 105 - 10 5 - 155 - 15

*

*

VrecVrec2020 underestimates, underestimates, not homogeneouslynot homogeneously , ,

Alveolar recruitmentAlveolar recruitment

VrecVrec2020 underestimates, underestimates, not homogeneouslynot homogeneously , ,

Alveolar recruitmentAlveolar recruitment

Volume (ml)

Paw (cmH2O)

Pneumonia

0

500

1000

1500

2000

2500

3000

0 10 20 30 40 50 60 70

All All ΔΔrec in rec in ΔΔFRC !!FRC !!All All ΔΔrec in rec in ΔΔFRC !!FRC !!

IT WORKS ! IT’S NOT CLINICAL PRACTICE !IT WORKS ! IT’S NOT CLINICAL PRACTICE !HOW TO MEASURE FRC ?HOW TO MEASURE FRC ?

OO2 2 analyseranalyser

FRCFRC

Gas Gas samplingsampling

Portable PCPortable PC

OXYGEN WASHIN WASHOUT

sidestream O2 analyser (OXIMON, Drager) (suction flow 200 ml/min).

FRC = QO2 / ΔFeO2(Δ FeO2 min: 20%)

QO2 = Q totale erogata – Q restituita al sistema – Q consumata

20

30

40

50

60

70

80

90

% O

2

WI O2 WO O2

FiO2

FeO2

WASHOUT vs HELIUM

-250

-200

-150

-100

-50

0

50

100

150

200

0 1000 2000 3000 4000

0

1000

2000

3000

4000

0 1000 2000 3000 4000

SLOPE 0.953INTERCEPT 53r2 0.960 Controlled

Diff

ere

nces

averages

IT WORKS ! MAY BE CLINICAL PRACTICE in near FUTUREIT WORKS ! MAY BE CLINICAL PRACTICE in near FUTURE

Paw [cmH2O]

%Determinanti del Reclutamento alveolre

0 5 10 15 20 25 30 35 40 45 500

10

20

30

40

50

Opening pressure

Closing pressure

Crotti et al. Am J Respir Crit Care Med 2001

Pplat Open the Lung

PEEP keep it open

Recruitment Recruitment maneuversmaneuvers

&&

SIGHSIGH

Slutsky styleSlutsky style

• Pressure = 35-50 cmHPressure = 35-50 cmH22OO

• Time = 20-40Time = 20-40secsec, 1-3 , 1-3 manoeuvremanoeuvre

• Mode: CPAP,APRV Mode: CPAP,APRV (lo vediamo nelle prove (lo vediamo nelle prove più tardi)più tardi)

• Check: BP,SpOCheck: BP,SpO22, on-line blood gas, on-line blood gas

• If vanishing effect If vanishing effect PEEP PEEP

Recruitment maneuverRecruitment maneuver

10 1215

710

Lachmann’s style

Foti G.,Cereda M.,et al. Intensive Care Med 2000, 26 (5) 501-07

Effects of periodic lung recruitment maneuvers on gas exchange and respiratory mechanics in mechanically ventilated acute respiratory distress syndrome (ARDS) patients.

Effects of periodic lung recruitment maneuvers on gas exchange and respiratory mechanics in mechanically ventilated acute respiratory distress syndrome (ARDS) patients.

Foti G.,Cereda M.,et al. Intensive Care Med 2000, 26 (5) 501-07

Alveolar Recruitment and Alveolar Recruitment and positioningpositioning

PRONATIONPRONATION

                              Am. J. Respir. Crit. Care Med., Volume 161, Number 5, May 2000, 1660-1665

The Prone Position Eliminates Compression of the Lungs by the Heart

RICHARD K. ALBERT and ROLF D. HUBMAYR

Perché funziona la pronazione ?

Cominciamo dalle cose semplici

Diaphragm position and

Distribution of ventilationDiaphragm position and

Distribution of ventilation

PRONEPRONE

SUPINESUPINE

Oxygenation Response to a Recruitment Maneuver during Supine and Prone Positions

in an Oleic Acid–Induced Lung Injury ModelNAHIT CAKAR, THOMAS VAN der KLOOT, MELYNNE YOUNGBLOOD, ALEX ADAMS, and AVI NAHUM

Am J Respir Crit Care Med Vol 161. pp 1949–1956, 2000

RMs should be repeated following prone positionRMs should be repeated following prone position

RMs effect

Proning effect

Prone + RMs effect

Recruitment by recover of spontaneous

breathing

spontaneous breathing controlled ventilation, NMBA

Diaphragm activity and recruitment

BIPAPBIPAPee

Respiro SpontaneoRespiro Spontaneo

BIPAP vs PCV:Gas exchange

Putensen et al. AJRCCM 2001; 164, 43-49

BIPAP

PCV

Set: BIPAP+PSV, Pmax = 35-40cmH2O Ti = 3-5 s.

RRBIPAP = 0.5-1 b.p.m.

Set: BIPAP+PSV, Pmax = 35-40cmH2O Ti = 3-5 s.

RRBIPAP = 0.5-1 b.p.m.

Dynamics of re-expansion of atelectasis during general anesthesiaRothen HU,Neuman p, Berglund J, Valtaysson J,Magnusson a and Hedenstierna G.British J of Anesthesia (1999):82, 4, 551-6

Start 1 sec.

1.5 sec. 3.5 sec.

L’insufflazione deve durare almeno 3 sec.L’insufflazione deve durare almeno 3 sec.

Sigh improves tollerance

to spontaneous breathing

Sigh improves tollerance

to spontaneous breathing

Conclusioni: -Pao2 ma…. non per moltoPao2 ma…. non per molto-Pplat per aprire-Pplat per aprire-PEEP per mantenere aperto-PEEP per mantenere aperto

RMs and SIGHRMs and SIGH

PronazionePronazione

Partial Ventilatory Partial Ventilatory SupportSupport

Why SIGH during PSV ?

Low PSV

TV Muscle activity

Derecruitment

SIGH

Is it Partial Ventilatory Support ?

End Inspiratory occlusion:End Inspiratory occlusion:

PMI = Pel,PMI = Pel,rsirsi - (PEEP+PS) - (PEEP+PS)PMI = PMPMI = PMuscuscIIndexndex

Foti G., Cereda M et al. AJRCCM 1997

Prone positioning attenuates and redistributes ventilator-induced lung injury in dogs

Alain Broccard, MD, FCCP; Robert S. Shapiro, MD; Laura L. Schmitz, MD; Alex B. Adams, MPH, RRT; Avi Nahum, MD, PhD; John J. Marini, MDCRITICAL CARE MEDICINE 1999;27:2574-2575

PRONEPRONE

SUPINESUPINE

Prone position as “Lung Protective Strategy”?Prone position as “Lung Protective Strategy”?

What has been proven ?

Prone - supine study

“The common theme of all the letter is that the use of prone position should not be descarded on the basis of the negative study by Gattinoni and collegues”

A. SlutskyNEJM Vol 346, n° 4,Jannuary 24, 2002 pag 297

End Inspiratory occlusionEnd Inspiratory occlusion::•Low PMI & low effort Low PMI & low effort (A)(A) •High PMI & high effort High PMI & high effort (B)(B)

Foti G., Patroniti N. Pesenti A. in “Tecniche di ventilazione artificiale”ed .Torri G.-Calderini E.

MV day 7.1±1.5 1.0 ± 0.3Est,cw 10 ±2 6 ±1Pao-Pes 19 ±3 29 ±2

1) what stays open at end expiration

depends on what has been opened at end inspiration

2) Adjusty PEEP to mantain recruitment

Conclusion:

BIPAP

PCV

Respiratory mechanics

Putensen et al. AJRCCM 2001; 164, 43-49

Recruitment maneuver and anesthesia

Post induction

Post recruitment

5’

45’

FiO2 0.4 FiO2 1

Br J Anaesth 1993 Dec;71(6):788-95

Re-expansion of atelectasis during general anaesthesia: a computed tomography study.

Rothen HU, Sporre B, Engberg G, Wegenius G, Hedenstierna G.

0

1

2

3

4

5

6

7

Paw 0 Paw 20 Paw 30 Paw 40

Area of atelectasis(cm2)

Ci vogliono almeno 30 cmH2O per riaprire le zone collassateCi vogliono almeno 30 cmH2O per riaprire le zone collassate

During OA injury PEEP trial

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 10 20 30 40 50 60 70

Volume (ml)

Paw (cmH2O)

Legionella Pneumoniae

All All ΔΔrec in rec in ΔΔEELV !!EELV !!All All ΔΔrec in rec in ΔΔEELV !!EELV !!

Closed Dilution Technique

Mass conservation

CiCiViVi

FRC ?FRC ?

CfCfVfVf

ViViCfCfCiCi

ViViFRCFRC

1

2

3

4

Helium dilution technique

Patroniti N et al. Intensive Care Med 2004; 30: 282

RM’s and hemodynamics

Recruitment maneuvers

Let’s require transpulmonary opening pressureequal to 30 cmH2O[“sticky atelectasis”]

Paw applied = 40 cmH2O

TP = 32 cm H2Oopened

TP = 20 cm H2Oclosed

“Soft” Cw EL/Etot = 0.8

“Stiff” Cw EL/Etot = 0.5

RMs Pressure for “Stiff” CwRMs Pressure for “Stiff” Cw RMs Pressure for “Stiff” CwRMs Pressure for “Stiff” Cw

Tecniche di reclutamento alveolare:

• Play with ventilatorsPlay with ventilators– RMs, SIGH

• PositioningPositioning– Pronation

• Partial Ventilatory SupportPartial Ventilatory Support– BIPAP– PSV

• 3 consecutive VC breaths3 consecutive VC breaths• Pplat 45 cmH2OPplat 45 cmH2O• No Insp. PauseNo Insp. Pause• Ti = 2.5 sec.Ti = 2.5 sec.

No commercial machine can perform No commercial machine can perform Sigh the way we studied itSigh the way we studied it

No commercial machine can perform No commercial machine can perform Sigh the way we studied itSigh the way we studied it

Courtesy Prof Rouby