AUTOMATED MODES OF VENTILATION:
SUPERIOR TO TRADITIONNAL MODES ?
François LELLOUCHE, MD, PhD
CONFLICTS OF INTEREST
- Research contracts with Drager medical
(travel expenses for the Canadian study on SmartCare)
- Research contracts with Hamilton medical to conduct Intellivent evaluation
(Salary of the research assistant)
- Program of research on automated ventilation and oxygen therapy:
Canadian for Innovation(Fonds des Leaders)/FRSQ grants
- President of a R&D compagny that develops automated systems for oxygen therapy
and mechanical ventilation
PLAN
Why automated modes are required ?
SmartCare: automated adjustment of pressure support, automated weaning
Intellivent: automated mechanical ventilation
Clinical evaluation
SmartCare
Intellivent
Conclusion: even equivalent would be worth…..
PLAN
Why automated modes are required ?
SmartCare: automated adjustment of pressure support, automated weaning
Intellivent: automated mechanical ventilation
Clinical evaluation
SmartCare
Intellivent
Conclusion: even equivalent would be worth…..
Why automated modes are required ?
Age pyramid US: 1950-2050
♂
♀
…. To the first
baby-boomers !!
Millions of people
Age Pyramid
Comorbidities
patients on MV
Number of clinicians
Angus JAMA 2000
Needham CCM 2005
2000
2020
2000
2020
16.7
18
16
605.898
700 000
14
500 000
400 000
252.577
300 000
Millions of days
n patients
600 000
12
10
8
5.8
3.8
6
200 000
4
100 000
2
6.6
1.5
2.3
0
0
Prolonged mechanical ventilation
Days of MV *
ICU LOS *
Hospital LOS *
Data for USA
Increasing number of patients with prolonged MV (> 96 hours)
Cost of MV : 16 billions of $/per year in 2003  60 billions of $/per year in 2020
(projection)
Zilberberg, CCM 2008
Why automated modes are required ?
Failure of the knowledge transfert
Weaning/protective ventilatory strategy
Rubbenfeld Respiratory Care 2004
Vilar Acta Anesthesiol Scand 2004
Scale Crit Care Med 2008
ARMA Study
6 vs 12 ml/Kg of PBW
…. To the first
baby-boomers !!
FAILURE TO IMPLEMENT
KNOWLEDGE
CHALLENGES FOR HEALTH
CARE SYSTEM
AUTOMATED SYSTEMS
COMMERCIALLY AVAILABLE AUTOMATED MODES
Mandatory Minute
Ventilation
Evita (Dräger)
Hewlett Anesthesia 1977
Automode
Servo (Maquet)
Holdt Resp Care 2001
ASV
G5 (Hamilton)
Laubscher IEEE Biomed Eng 1994
SmartCare
Evita XL, V500 (Dräger)
Dojat Int J Clin Monit 1992
ASV  Intellivent
G5 (Hamilton)
Brunner 2002
PLAN
Why automated modes are required ?
SmartCare: automated adjustment of pressure support, automated weaning
Intellivent: automated mechanical ventilation
Clinical evaluation
SmartCare
Intellivent
Conclusion: even equivalent would be worth…..
Rationale for weaning automation
Weaning protocols are efficient (Ely NEJM 1996, Saura ICM 1996, Kollef CCM 1997, Marelich 2000)
Weaning protocols are recommended (Mc Intyre Chest 2001, Boles ERJ 2007)
…..but many obstacles (Ely AJRCCM 1999, Vitacca ICM 2001) to implement weaning protocols
trainings on a regular basis required, problems with new protocols and new practices acceptance…
Automated Weaning: SmartCare
1) Automated adaptation of PSV level
2) Automated weaning protocol
–
–
automatic decrease of the PSV
automatic SBT
Ventilator in PSV
Patient Monitor
Patient Monitor
Alarms
Alarms
Control
Control
Patient
Automated pressure support
Output
Automated Weaning
Input RR, TV, EtCO 2
Automatic
SmartCare
Weaning
System
Processing
Automated Weaning : SmartCare
• Pressure support ventilation
• Automated adaptation of the PS level
 Comfort Zone : 15 < RR < 30 breath/min
 Tidal Vol > min level, ETCO2 < safety limit
• Automated weaning strategy
 Progressive decrease of the PS level
 Spontaneous breathing test before extubation
 Recommendation for extubation
PEEP and FiO2 are not managed by the system
Dojat et al. Int J Clin Monit Comput 1992
Level of Pressure support (cmH
2O)
Example of Weaning with «SmartCare »
Automated
reduction of the
PSV level
18
16
14
Message:
« separation from ventilator »
12
10
8
Minimum level of PS
6
4
PEEP must be  5 cmH2O
Adaptation
Observation
« Automated SBT »
2
Maintain
E
X
T
U
B
A
T
I
O
N
0
0:00
0:28
0:57
1:26
Time (h:min)
1:55
2:24
2:52
PLAN
Why automated modes are required ?
SmartCare: automated adjustment of pressure support, automated weaning
Intellivent: automated mechanical ventilation
Clinical evaluation
SmartCare
Intellivent
Conclusion: even equivalent would be worth…..
Intellivent stems from ASV
• ASV = Pressure controlled and Pressure assisted mode
– Automatic transition from controlled to assisted ventilation
– Automatic adjustement of RR (Ti/Te) and TV (Pressure, cycling off) for
• Constant minute ventilation  SET BY THE CLINICIAN WITH ASV
• Minimized work of breathing (based on patient’s respiratory mechanics: time
constant and resistance continuously evaluated)
• Minimized intrinsic PEEP
– Based on physiologic Otis and Meade equations
– With ASV NO ADJUSTMENT OF PEEP AND FiO2
INTELLIVENT
Otis, JAP 1950
Mead, JAP 1960
Automated Ventilation : Intellivent
1) Ventilation controller: Automated adaptation of minute ventilation (RR, TV) / EtCO2
2) Oxygenation controller: Automated adaptation of PEEP and FiO2 / SpO2
Ventilator
Patient Monitor
Patient Monitor
Alarms
Alarms
Control
Control
Patient
Output
Automated Ventilation (RR,TV)
Automated Oxygenation
(PEEP/FiO2)
Input RR, TV, EtCO 2
SpO2, Heart Lung Index
Automatic
Weaning
Intellivent
System
Processing
PEEP limitation - Heart-Lung Index (HLI)
HEART vs LUNG: not OK
Pulse oxymeter
Plethysmogram
(mm)
Delta PP
Arterial Pressure
(mmHg)
Delta POP
Airway Pressure
(cmH2O)
HEART vs LUNG: OK
Adaptive Support Ventilation
Still 3 knobs…
Intellivent: the NO knobs concept…
FULLY
AUTOMATIC
Intellivent = fully automatic
Gender, patient height
 estimation of the target minute ventilation
Ventilation
controller
ASV
Clinical situations
 modifies the target for the controllers
Press Start !
EtCO2
Oxygenation
controller
SpO2
PLAN
Why automated modes are required ?
SmartCare: automated adjustment of pressure support, automated weaning
Intellivent: automated mechanical ventilation
Clinical evaluation
SmartCare
Intellivent
Conclusion: even equivalent would be worth…..
INITIAL CLINICAL EVALUATIONS OF SMARTCARE
(prototype = NéoGanesh)
Dojat et al. AJRCCM 1992
Maintain of the patients in the comfort zone 95% of time
19 patients
Dojat et al. AJRCCM 1996
Good performances of the system to predict extubation success/failures
38 patients
Dojat et al. AJRCCM 2000
Efficiency of the system to maintain the patient in a comfort zone
Reduction of time with high P0.1
56 modifications of PSV/24 hrs vs 1 modification PSV/24 hrs
10 patients
Bouadma, Lellouche et al. Intensive Care Med 2005
Possibility to ventilate patients with the system during prolonged periods (up to
12 days)-Pilot study for multicenter RCT
42 patients
1st Multicenter Randomized Study
Objective of the study
Automated weaning
VS
Usual protocolized weaning
Mechanical ventilation
Question at least 2 times a day:
Weaning possible ?
Weaning possible if all following criteria are present:
- Improvement of condition having led to intubation
- Absence of uncontrolled severe infection
- Correction of metabolic disorders
- Adequate hemoglobin level
- No hemodynamic instability
- PaO2 > 8.5 kPa with FIO2  0.40 and PEEP  5 cmH2O
NO
YES
Initiation of weaning
• Stop or lowering of sedation
• Level of Pressure Support : 20
cmH2O
NO
PS level 20 cmH 2O above PEEP > 60
minutes ?
YES
Spontaneous breathing test feasible if after 60'
with
PS 20 cmH2O, PEEP  5 cmH2O (all must be
present):
- Respiratory rate  30/'
- Tidal volume  6 ml/kg
- No hemodynamic instability
- SpO2  90% and FIO2  0.40
- No other contra-indication
Extubation criteria (all must be
present)
- Respiratory rate  30/'
- Pulse < 120/'
- Syst. ABP < 180 and > 90 mmHg
- No hemodynamic instability
- PaO2  8.5 kPa and FIO2  0.40
- pH > 7.30
Question at least 2 times a day:
Spontaneous breathing test feasible ?
Adaptation
of PS
and/or
NO
PEEP level
YES
Spontaneous breathing test during 30'
First choice: Pressure support 10 cmH 2O, ± PEEP 5
cmH2O
Other choices:
- T-piece trial
- CPAP, flow 30 l/min. PEEP  5 cmH2O
Extubation criteria present ?
NO
YES
Extubation possible ?
- Level of consciousness
OK
- Efficient swallowing
- Efficient cough
Primary end point:
Weaning time
NO
Patient weaned but extubation not possible
YES
EXTUBATION
Weaning process can begin if:

The cause of the respiratory failure is partially or completely controlled, including a
SpO2  90% under FIO2  0.5 and PEEP  5 cm H2O

Hemodynamic stability (Systolic Blood Pressure between 90 and 160mm Hg + Pulse
between 60 and 125 /minute + absence of uncontrolled arrhythmias)

Temperature < 39°C

Haemoglobin  8 g/dL

Absence of significant hydro-electrolytes abnormalities

Patients can follow simples orders and there is not need for high dose of sedatives

For neurological patients:
(inclusion  first extubation)
Glascow Coma Scale > 8, Intra-Cranial Pressure < 20 mmHg, Cerebral Perfusion
Pressure > 60 mmHg
Those patients who accomplish these criteria will follow a spontaneous breathing test (2 hours
T tube or Pressure Support Ventilation with 7 cm H2O of pressure support and Positive End
Expiratory Pressure  5 cm H2O). No tolerance to spontaneous breathing test will be
considerer if:

Respiratory Rate > 35 bpm + clinical manifestation *

Hypoxemia (PaO2 < 60 mmHg under O2 flow  4 L/min)

Acidosis (pH  7.3)
* Clinical manifestations: Systolic Blood Pressure  160 mmHg or  90 mmHg, Heart Rate 
140 bpm or augmentation of 25% of baseline, new arrhythmia, lower conscience level,
sweating or agitation.
1.
Patients will be extubated if they successfully complete the 2 hours spontaneous
breathing trial and they have an adequate cough
2.
For patients that do not tolerate the spontaneous breathing test, weaning will continue
on Pressure Support Ventilation. Pressure Support will be adjusted to achieve a
respiratory frequency of 25-30 bpm and a good clinical adaptation. Pressure Support
will be diminished as soon as possible following patient’s clinical tolerance. Patients
will be extubated if tolerating low Pressure Support levels (next to 10 cm H2O) with
low PEEP levels ( 5 cm H2O) if clinical tolerance and cough are adequate.
Lellouche et al, AJRCCM 2006,174:894-900
WEAN pilot study
Co-PI: K.Burns/F.Lellouche
RCT
PILOT/ FEASABILITY
SmartCare vs written weaning protocols
8 Centers
Primary outcomeacceptance of weaning protocols
OUTCOME DATA
Variables
Time to first extubation, days median (25-75)
Time to first successful extubation, days median (25-75)
Reintubation, n (%)
Patients with prolonged ventilation (>21 days), n (%)
Ever had tracheostomy, n (%)
Total duration of intubation, days median (25-75)
Duration of ICU stay, days median (25-75)
Duration of Hospitalization, days median (25-75)
ICU death, n (%)
Protocol
Weaning
(n=43)
4 (2-12)
5 (3-19)
11 (25.5%)
6 (18.2%)
15 (34.9%)
10.5 (8, 17.5)
9 (5, 25)
31.5 (16. 49.5)
9 (20.9%)
Automated
Weaning
(n=51)
3 (2-5)
4 (2-7)
9 (17.7%)
0
8 (16%)
12 (6, 25)
7 (5, 14)
22 (14, 33)
9 (17.7%)
p-value
0.02
0.10
0.35
0.01
0.04
0.37
0.13
0.19
0.69
Feasibility for a
larger RCT ?......
Automated weaning (SmartCare) vs local weaning protocols
in post-surgical patients
Randomized Controlled Trial
Post-op patients with MV > 9 hours
300 patients included
94±144 hours (SmartCare)
118±165 hours (Protocols)
(P=0.12)
Randomized Controlled Trial
Medical patients
102 patients included
Rose Intensive Care Medicine 2008
Lellouche, AJRCCM 2006
Schadler, ATS 2009
In the context of increasing gap between needs and supply
to manage patients on MV, both studies are positive :
Better (or same outcome) with less human interventions
EVALUATION OF INTELLIVENT
= FULLY AUTOMATIC MECHANICAL VENTILATION
 Feasibility study
 Does the system can safely manage stable patients
after cardiac surgery ?
 Does the system reduce the workload ?
Context: recent data (from cardiac surgery database)
showing the need to reduce tidal volume after cardiac
surgery (prophylactic protective ventilation…)
Impact of tidal volumes even in patients with normal lungs
3434 patients after CABG or valve surgery
Multivariate analysis
 High tidal volumes after cardiac surgery are independant risk factors for
- organ dysfunction
- ICU Length of stay
Lellouche et al ATS 2010
Non parametric logistic regression
Cardiac surgery
= interesting to evaluate a fully automated system
• Dynamic clinical condition
• Within 2-4 hours
– Temperature 35˚C  37˚C (↗CO2 production)
– FiO2 70  40-30%
– Controlled  assisted ventilation
• Workload related to mechanical ventilation settings:
– Adjustment of minute-ventilation
– PEEP/FiO2 weaning
– Switch to PSV
Study design
ICU admission
Consent
Intellivent group
Automated ventilation
Modified G5
15 minutes
Criteria for
Consent
Randomization
SURGERY
Connection to a
G5 ventilator
Settings by the
anesthesiologist
Inclusion criteria +
Exclusion criteria -
4 hours
Control group
Protocolized
Ventilation
G5 : SIMV+PSV
Inclusion Criteria
- Hemodynamic stability
1. < 3 red-cell Tf units within last 15 min
2. Epi or norepinephrine below < 1 mg/h
3. Bleeding <100 ml within last 15 min
- No anuria
Exclusion Criteria
- Unexpected surgical procedure
- Major complication during surgery
- Early extubation expected (< 1 hour)
- Broncho-pleural fistula
- Study ventilator not available
Data from the ventilator recorded
Timing of the interventions
Time with optimal/non optimal ventilation
RESULTS
- 90 consent signed
Delayed surgery (morning to afternoon cases)
Surgery postponed (emergent cases)
Hemodynamic instability at ICU arrival
 60 patients included from 07/2009 to 12/2009
. ALL
THE PATIENTS COMPLETED THE STUDY
. 1 patient needed re-operation for massive bleeding 1 hour after the
randomization (Intellivent group).
. Duration of the study (min):
Control group
Intellivent group
194 + 43
207 + 47
P value
0.24
15
Tidal Volume (ml/Kg PBW)
14
Conventionnal
Intellivent
13
12
11
10
9
8
7
6
5
H0
H1
H2
H3
*
*
*
H4
RESULTS: MAIN OUTCOME
% 100
n
160
148
90
140
80
70
Control arm
Groupe
Controle
120
60
Groupe
Intellivent
Intellivent
arm
100
50
80
40
*
30
60
*
20
40
10
20
0
OPTIMALE
ACCEPTABLE
NON
ACCEPTABLE
Optimal ventilation
(TV < 10ml/Kg of PBW, Pressure < 30, SpO2, EtCO2)
0
5
Control Groupe
Intellivent
Groupe
arm Intellivent
Controle
arm
Number of manual settings
PLAN
Why automated modes are required ?
SmartCare: automated adjustment of pressure support, automated weaning
Intellivent: automated mechanical ventilation
Clinical evaluation
SmartCare
Intellivent
Conclusion: even equivalent would be worth…..
Computers in ICU: panacea or plague ?
East TD, Respiratory Care 1992
AUTOMATED MODES OF VENTILATION:
SUPERIOR TO TRADITIONNAL MODES ?
Conclusion:
AUTOMATED MODES OF VENTILATION:
SUPERIOR TO HUMAN SETTINGS ?
Even results equivalent to traditionnal modes would be worth…..
in the demographic context
Several studies demonstrate positive results to reduce the duration
of mechanical ventilation and potential for workload reduction
With…first generation systems
More evaluation required (Intellivent …)
Room for improvement in the next years
We should accept that automated systems could be superior
to humans for specific tasks…
THANKS !
PA Bouchard
C Bouchard
MC Ferland
P Dubé
….