Il Reclutamento Alveolare
Giuseppe Foti
Istituto di Anestesia e Rianimazione
Università di Milano-Bicocca dir. Prof. A. Pesenti
Ospedale S. Gerardo Monza
Reclutamento Alveolare:
riapertura zone collassate
PEEP 5
PEEP 10
PEEP 15
•E’ la PaO2 il miglior indicatore di 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  Rec dal versante alveolare ?
Chord Cpl 
Alveolar recruitment 
Estimating Δrec by P/V curve analysis
Assumes that FRC immediately equalizes
coming from different PEEP
FRC is different
coming from different Ventilatory SET UP !!
1200
Vrec20 (ml)
Vrec20,He (ml)
*
1000
800
Vrec20 underestimates, not homogeneously ,
600
Alveolar recruitment
400
*
200
0
-200
5 - 10
5 - 15
Pneumonia
Volume (ml)
3000
2500
2000
1500
1000
All Δrec in ΔFRC !!
500
0
0
10
20
30
40
50
60
70
Paw (cmH2O)
HOW
TO NOT
MEASURE
FRC
?
IT WORKS
! IT’S
CLINICAL
PRACTICE
!
OXYGEN WASHIN WASHOUT
sidestream O2 analyser
(OXIMON, Drager)
(suction flow 200
ml/min).
Gas
sampling
FRC
Portable PC
O2 analyser
FRC = QO2 / ΔFeO2
(Δ FeO2 min: 20%)
QO2 = Q totale erogata – Q restituita al sistema – Q consumata
90
80
FiO2
% O2
70
60
FeO2
50
40
30
20
WI O2
WO O2
WASHOUT vs HELIUM
SLOPE
INTERCEPT
r2
0.953
53
0.960
Controlled
4000
200
150
3000
Differences
100
2000
50
0
-50 0
1000
2000
3000
4000
-100
1000
-150
-200
averages
-250
0
0
1000
2000
3000
4000
IT WORKS ! MAY BE CLINICAL PRACTICE in near FUTURE
Determinanti del Reclutamento alveolre
50
PEEP keep it open
Pplat Open the Lung
%
40
Opening
pressure
30
Closing
pressure
20
10
0
0
5
10 15 20 25 30 35 40 45 50
Paw [cmH2O]
Crotti et al. Am J Respir Crit Care Med 2001
Recruitment
maneuvers
&
SIGH
Slutsky style
•
•
•
•
•
Pressure = 35-50 cmH2O
Time = 20-40sec, 1-3 manoeuvre
Mode: CPAP,APRV (lo vediamo nelle prove più tardi)
Check: BP,SpO2, on-line blood gas
If vanishing effect   PEEP
Recruitment maneuver
10
7
12
10
15
Lachmann’s style
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
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
positioning
PRONATION
Perché funziona la pronazione ?
Cominciamo dalle cose semplici
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
Diaphragm position and
Distribution of ventilation
PRONE
SUPINE
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
Prone + RMs effect
Proning effect
RMs effect
RMs should be repeated following prone position
Recruitment
by recover of
spontaneous breathing
Diaphragm activity and recruitment
spontaneous breathing
controlled ventilation, NMBA
BIPAP
e
Respiro Spontaneo
BIPAP vs PCV:
Gas exchange
BIPAP
PCV
Putensen et al. AJRCCM 2001; 164, 43-49
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
anesthesia
Rothen HU,Neuman p, Berglund J, Valtaysson J,Magnusson a and Hedenstierna G.
British J of Anesthesia (1999):82, 4, 551-6
Start
1.5 sec.
1 sec.
3.5 sec.
L’insufflazione deve durare almeno 3 sec.
Sigh improves
tollerance
to spontaneous
breathing
Conclusioni:
-Pao2 ma…. non per molto
-Pplat per aprire
-PEEP per mantenere aperto
Partial Ventilatory
Support
RMs and SIGH
Pronazione
Why SIGH during PSV ?
Low PSV
 TV
 Muscle
activity
Derecruitment
SIGH
Is it Partial Ventilatory
Support ?
End Inspiratory occlusion:
PMI = Pel,rsi - (PEEP+PS)
PMI = PMuscIndex
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, MD
CRITICAL CARE MEDICINE 1999;27:2574-2575
PRONE
SUPINE
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. Slutsky
NEJM Vol 346, n° 4,Jannuary 24, 2002 pag 297
End Inspiratory occlusion:
•Low PMI & low effort (A)
•High PMI & high effort (B)
Foti G., Patroniti N. Pesenti A. in “Tecniche di ventilazione artificiale”ed .Torri G.-Calderini E.
MV day
Est,cw
Pao-Pes
7.1±1.5
10 ±2
19 ±3
1.0 ± 0.3
6 ±1
29 ±2
Conclusion:
1) what stays open at end expiration
depends on what has been opened
at end inspiration
2) Adjusty PEEP to mantain recruitment
Respiratory mechanics
BIPAP
PCV
Putensen et al. AJRCCM 2001; 164, 43-49
Recruitment maneuver and anesthesia
FiO2 0.4
Post induction
Post recruitment
5’
45’
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.
7
Area of atelectasis
(cm2)
6
5
4
3
2
1
0
Paw 0
Paw 20
Paw 30
Paw 40
Ci vogliono almeno 30 cmH2O per riaprire le zone collassate
During OA injury
PEEP trial
Legionella Pneumoniae
Volume (ml)
2000
1800
1600
1400
1200
1000
800
600
All Δrec in ΔEELV !!
400
200
0
0
10
20
30
40
50
60
70
Paw (cmH2O)
Closed Dilution Technique
Ci
Vi
FRC
Mass
conservation
Cf
Vf
?
Ci
- Vi
FRC = Vi
Cf
Helium dilution technique
1
3
2
4
Patroniti N et al. Intensive Care Med 2004; 30: 282
RM’s and hemodynamics
Recruitment maneuvers
Let’s require transpulmonary opening pressure
equal to 30 cmH2O
[“sticky atelectasis”]
Paw applied = 40 cmH2O
“Soft” Cw
“Stiff ” Cw
EL/Etot = 0.8
TP = 32 cm H2O
EL/Etot = 0.5
TP = 20 cm H2O
opened
closed
 RMs Pressure for “Stiff” Cw
Tecniche di reclutamento alveolare:
• Play with ventilators
– RMs, SIGH
• Positioning
– Pronation
• Partial Ventilatory Support
– BIPAP
– PSV
• 3 consecutive VC breaths
• Pplat 45 cmH2O
• No Insp. Pause
• Ti = 2.5 sec.
No commercial machine can perform
Sigh the way we studied it
Courtesy Prof Rouby