Il reclutamento alveolare

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Il Reclutamento Alveolare

Giuseppe Foti

Istituto di Anestesia e Rianimazione

Università di Milano-Bicocca dir. Prof. A. Pesenti Ospedale S. Gerardo Monza

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Reclutamento Alveolare:

riapertura zone collassate

PEEP 5 PEEP 10 PEEP 15

•E’ la PaOE’ la PaO₂₂ il miglior indicatore di Rec ? il miglior indicatore di Rec ?

(3)

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

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Chord Cpl

Chord Cpl 

Alveolar recruitment

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Assumes that FRC immediately equalizes

coming from different PEEP

Estimating

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FRC is different

coming from different Ventilatory SET UP !!

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Vrec

Vrec₂₀₂₀ (ml) (ml) Vrec

Vrec_20,He_20,He (ml) (ml)

-200 -200 0 0 200 200 400 400 600 600 800 800 1000 1000 1200 1200 5 - 10 5 - 10 5 - 155 - 15

*

Vrec

Vrec₂₀₂₀ underestimates, _{underestimates,}not homogeneously_{not homogeneously} ,_,

Alveolar recruitment

Vrec

Vrec₂₀₂₀ underestimates, underestimates, not homogeneouslynot homogeneously , , Alveolar recruitment

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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

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IT WORKS ! IT’S NOT CLINICAL PRACTICE !

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O O₂₂analyseranalyser FRC FRC Gas Gas sampling sampling Portable PC Portable PC OXYGEN WASHIN WASHOUT

sidestream O2 analyser (OXIMON, Drager)

(suction flow 200 ml/min).

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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

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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 0.953 INTERCEPT 53 r2_0.960 Controlled D if fe re n ce s averages

IT WORKS ! MAY BE CLINICAL PRACTICE in near FUTURE

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Paw

[cmH₂O]

%

Determinanti del Reclutamento alveolre

0 5 10 15 20 25 30 35 40 45 50 0 10 20 30 40 50 Opening pressure Closing pressure

Crotti et al. Am J Respir Crit Care Med 2001

Pplat Open the Lung

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Recruitment

maneuvers

&

SIGH

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Slutsky style

• Pressure = 35-50 cmH_{Pressure = 35-50 cmH}2₂OO

• Time = 20-40_{Time = 20-40}sec_sec, 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,SpO_{Check: BP,SpO}2₂, on-line blood gas, on-line blood gas

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Recruitment maneuver

10 12 15

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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.

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Effects of periodic lung recruitment maneuvers on gas exchange and respiratory mechanics in mechanically ventilated acute

respiratory distress syndrome (ARDS) patients.

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Alveolar Recruitment and

positioning

PRONATION

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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 ?

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Diaphragm position

and

Distribution of ventilation

Diaphragm position

and

Distribution of ventilation

PRONE

SUPINE

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Oxygenation Response to a Recruitment Maneuver during Supine and Prone Positions in an Oleic Acid–Induced Lung Injury Model

NAHIT 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 position

RMs effect

Proning effect

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Recruitment

by recover of

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spontaneous breathing controlled ventilation, NMBA

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BIPAP

e e

Respiro Spontaneo

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BIPAP vs PCV:

Gas exchange

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

BIPAP PCV

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Set: BIPAP+PSV, Pmax = 35-40_cmH2O Ti = 3-5 s.

RR_BIPAP = 0.5-1 b.p.m.

Set: BIPAP+PSV, Pmax = 35-40_cmH2O Ti = 3-5 s.

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Dynamics of re-expansion of atelectasis during general anesthesia

Rothen 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.

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Sigh improves tollerance to spontaneous breathing Sigh improves tollerance to spontaneous breathing

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Conclusioni:

-

Pao2 ma…. non per molto_{Pao2 ma…. non per molto}

-Pplat per aprire

-PEEP per mantenere aperto

RMs and SIGH RMs and SIGH Pronazione Pronazione Partial Ventilatory Partial Ventilatory Support Support

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Why SIGH during PSV ?

Low PSV

 TV

 Muscle

activity

Derecruitment

SIGH

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Is it Partial Ventilatory Support ?

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End Inspiratory occlusion:

PMI = Pel,

_rsi_rsi

- (PEEP+PS)

_{- (PEEP+PS)}

PMI = PM

PMI = PMuscuscIIndexndex

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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, MD

CRITICAL CARE MEDICINE 1999;27:2574-2575

PRONE

SUPINE

Prone position as “Lung Protective Strategy”?

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What has been proven ?

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“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. Slutsky

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End Inspiratory occlusion

:

• Low PMI & low effort

_{Low PMI & low effort}

(A)

_(A)

• High PMI & high effort

_{High PMI & high effort}

(B)

_(B)

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MV day 7.1±1.5 1.0 ± 0.3

Est,cw 10 ±2 6 ±1

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1) what stays open at end

expiration

depends on what has been opened

at end

inspiration

2)

Adjusty PEEP to

mantain

recruitment

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BIPAP PCV

Respiratory mechanics

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Recruitment maneuver and anesthesia Post induction Post recruitment 5’ 45’ FiO2 0.4 FiO2 1

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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 collassate

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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

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Closed Dilution Technique

Mass conservation Ci Ci Vi Vi FRC ? FRC ? Cf Cf Vf Vf

Vi

Cf

Ci

Vi

FRC





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1

2

3

4

Helium dilution technique

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Recruitment maneuvers

Let’s require transpulmonary opening pressure equal to 30 cmH₂O [“sticky atelectasis”] Paw applied = 40 cmH₂O TP = 32 cm H₂O opened TP = 20 cm H₂O closed “Soft” Cw E_L/E_tot = 0.8 “Stiff” Cw E_L/E_tot = 0.5 

 RMs Pressure for “Stiff” Cw_{RMs Pressure for “Stiff” Cw}



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Tecniche di reclutamento alveolare:

• _{Play with ventilators}_{Play with ventilators}

– RMs, SIGH

• Positioning_Positioning

– Pronation

• _{Partial Ventilatory Support}_{Partial Ventilatory Support}

– BIPAP – PSV

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• 3 consecutive VC breaths_{3 consecutive VC breaths}

• Pplat 45 cmH2O_{Pplat 45 cmH2O}

• No Insp. Pause_{No Insp. Pause}

• Ti = 2.5 sec._{Ti = 2.5 sec.}

No commercial machine can perform

Sigh the way we studied it

No commercial machine can perform No commercial machine can perform

Sigh the way we studied it Sigh the way we studied it

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