Post on 22-Feb-2019
ECMO : da dove siamo partiti?
Antonio Pesenti MD
University of Milano BicoccaItaly
A Brilliant Investigator’s Career
• First decade :
– A new method of respiratory extracorporeal support
• Second decade :
– Respiratory Extracorporeal Support : state of the Art
• Third decade :
– Respiratory Extracorporeal Support : History
Buying time with artificial lungs
Zapol WM, Kits RJ, NEJM 1972; 286 (12)
NIH ECMO STUDY
• FAST ENTRY CRITERIA
– PaO2 < 50 mmHg 3 times 1hr interval ( 2 hrs)
– Fi O2 1 - PEEP > 5 cmH2O
• SLOW ENTRY CRITERIA
• PaO2 < 50 mmHg 3 times 6hr interval (12 hrs)
• FiO2 0.6 - PEEP > 5 cm H2O
– OR
• Qs/Qt > 30% at FiO2 1
NIH
• Expected mortality rate was > 65%
• Observed mortality rate was 92%
• Investigators decided to proceed to an additional data collection :
• All ARF patients undergoing positive airway pressure with an FiO2 > .5 for more than 24 hrs
NIH ECMO STUDY
NIH ECMO Trial
0
10
20
30
40
50
0 2 4 6 8 10 12 14
Days From Entry
Su
rviv
ing
Pati
en
ts MV
ECMO
Zapol WM: JAMA 1979; 242: 2193-6
From Conrad SA slide on internet
Ted Kolobow MD
Why Did ECMO Fail?
• Severely diseased lungs have a chance to heal only if the environment remains conducive to the healing of the lungs.
• This environment does not consist of high airway pressures, high tidal volumes, high PEEP, high FiO2…..
Luciano Gattinoni, MD
From Oxygenators:Buying time with artificial lungs
Zapol WM, Kits RJ, NEJM 1972; 286 (12)
ToArtificial lungs:Resting the lung
Gattinoni L 1976? Personal Communication
Artificial Lung
CONTENTION
• We can do without Mechanical Ventilation if we do not need to breath out CO2 trough the lungs
Kolobow et al Trans. Am. Soc. Artif. Intern. Organs. 1977. 23: 17
Extracorporeal Gas Exchange
• ECMO
– high blood flow ( 4-6 l/min)
• ECCO2R
– low blood flow ( 0.5 – 2.5 l/min)
The three evils of MECHANICAL VENTILATION
• VILI
• VAP
• SEDATION
ARTIFICIAL ORGANS FOR RESPIRATORY FAILURE
Ventilatory
Membrane lung
Parenchimal
Mechanical ventilation
NEJM 2002:346: 1281
ARDS Pathophysiology
• ARDS is not just an hypoxic syndrome
• ARDS is a “Hypercapnic” syndrome
– Pulmonary vascular occlusion
– High dead space
– High minute ventilation
– High PAP
Extracorporeal CO2 removal
• Reducing ventilation anywhere down to 0 according to the
proportion of VCO2 removed
• No ventilation , no VILI
Early ARDS
• ECCO2R to :
– prevent intubation
– extend NIV application
J. M. Tonnelier Intensive Care Med 2003: 29: 2077
Variable No tube To tube P tresh sens spc
PaO2/FiO2
basal111±38 105±33 .06 <102 0.6 0.66
PaO2/FiO2
1 hr195±66 168±48 0.09 <175 0.59 0.65
RR basal
35±5 36±5 0.27 >31 0.9 0.25
RR 1 hr
27±5 30±7 0.006 >29 0.63 0.67
Antonelli : Crit Care Med. 2007 Jan;35(1):18-25.
A multiple-center survey on the use in clinical practice of NIV as a first-line intervention for ARDS.
ARDS Status
• ECCO2R to :
– from 6 to 3ml/kg and lower
Hager Am J Resp Crit Care Med 2005
Association between mortalityand Pplat
The technique seems to prevent the pulmonary barotrauma and
extrapulmonary derangements caused by conventional mechanical
ventilation
PaCO2 (mmHg) Arterial pH
baseline T0 T24 T48 T72 baseline T0 T24 T48 T72
7.0
7.1
7.2
7.3
7.4
7.5
*
* * *
***
*
30
40
50
60
70
80
90
Anesthesiology. 2009 ;111: 826
T. Bein et al : Intensive Care Med 2013
ARDS Recovering
• ECCO2R to allow :
– early spontaneous breathing
– early extubation
– early NIV or CPAP
ECMO REVISITED
The International Journal of Artificial Organs 10, 1, 1987
Extracorporeal CO2 RemovalPhysiological Side Effects
• Extracorporeal Carbon Dioxide Removal is an experimental technique
• Extracorporeal Carbon Dioxide Removal effects on outcome are not known
• Extracorporeal Carbon Dioxide Removal Physiology and Pathophysiology is only partially understood
Kolobow et al Trans. Am. Soc. Artif. Intern. Organs. 1977. 23: 17
6 4 2 0,40
20
40
60
80
100
Gas Flow Membrane Lung (l/min)
VCO2 Membrane Lung %
VCO2 Natural Lung %
What influences the respiratory drive in COPD pts undergoing PECOR?
0
5
10
15
20
25
30
35
40 45 50 55 60 65
EAdipeak
(μV)
PaCO2 (mmHg)
4
3
2
1
1) GF 10 L/min, VCO2ML 134 mL/min2) GF 5 L/min, VCO2ML 108 mL/min3) GF 2.5 L/min, VCO2ML 83 mL/min4) GF 0 L/min, VCO2ML 0 mL/min
R² = 0.96
What influences the respiratory drive in ARDS pts undergoing ECMO?
R² = 0,1906
0
5
10
15
20
25
30,0 35,0 40,0 45,0 50,0 55,0
EAdipeak
(μV)
PaCO2 (mmHg)
Does negative intrathoracic pressure favors lung edema ?
Annals ATS aug 2013