This document discusses different modes of mechanical ventilation and their use over time. It provides data from several international studies on the types of ventilation modes used for different patient populations and conditions. Some key findings include: - In the 1950s, the mortality rate from respiratory paralysis was around 87% but decreased significantly with the introduction of invasive mechanical ventilation. - By the 1980s, the most commonly used ventilation modes were CMV/ACV (55%) and IMV/SIMV (26%). - More recent international studies show A/C is still the most commonly used mode but SIMV-PSV is becoming more frequent, especially in certain regions like Latin America. - A prospective randomized trial of 79 ARDS

1. Andrés Esteban
Modes of Mechanical Ventilation:
Is There Anyone Better?
Hospital Universitario de Getafe

2. 1952:
Copenhagen polio epidemic
First month
31 patients with respiratory
paralysis
27 patients died (87%)

3. 0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7 8
Mortality July 1952  March 1953
Months

4. QUESTIONAIRE MAILED ………… 3982
QUESTIONAIRE RETURNED ……. 1272 (32%)
IMV IS USED AS
PRIMARY MODE OF VENT…….... 71.6 %
B. Venus et al 1987
Crit Care Med 15:530

5. Ventilatory Modes
CMV / ACV ………….... 55 %
IMV / SIMV ……………. 26 %
SIMV + PSV …………… 8 %
PSV ……………………. 8 %
PCV ……………………. 1 %
A. Esteban, I. Alía et al.
Chest 1994;106:1188

6. USA
CAN SPA ARG BRA CHI POR URU TOTAL
A / C 34 62 68 40 75 44 25 47
SIMV 6 7 9 4 5 -- 20 6
P S 18 11 10 10 5 34 2 15
SIMV / PS 34 13 7 31 17 13 52 25
OTHERS 7 6 6 15 2 9 -- 7
A. Esteban, A. Anzueto, I. Alía et al
Am J Respir Crit Care Med 2000;161:1450
Modes of ventilation (%)

7. Canada
U.S.A.
Argentina
Bolivia
Brazil
Chile
Colombia
Ecuador
México
Perú
Uruguay
Venezuela
England
France
Greece
Ireland
Italy
Portugal
Spain
Tunizia

8. 0
1000
2000
3000
4000
5000
1 4 7 10 13 16 19 22 25 28
0
10
20
30
40
50
60
70
80
90
100
Patients A/C PCV PS
SIMV SIMV+PS VNI Others
Numbersofpatientsmechanicallyventilated
Days from the start of mechanical ventilation
Percentageofpatientsventilatedwith
eachventilatorymode
A.Esteban, A. Anzueto, F. Frutos, I. Alía et al.
JAMA 2002;287:345-355

9. A. Esteban, A. Anzueto, F. Frutos, et al.
JAMA 2002;287:345-355
International study of 5183 patients
449 patients (8.6%) meet the ARDS criteria
Mode of ventilation
 Volume controlled: 69%
 Pressure controlled: 24%

10. USA
CANADA
AC
SIMV
SIMV-PSV
PSV
PCV
46 %
6 %
15 %
2 %
20 %
AC
SIMV
SIMV-PSV
PSV
PCV
52%
4 %
10 %
4 %
22 %
AC
SIMV
SIMV-PSV
PSV
PCV
39 %
3 %
21 %
6 %
24 %
LATIN
AMERICA
AC
SIMV
SIMV-PSV
PSV
PCV
85 %
3 %
6 %
2 %
2 %
AC
SIMV
SIMV-PSV
PSV
PCV
74 %
5 %
9 %
2 %
7 %
AC
-----
SIMV-PSV
-----
PCV
71 %
14 %
7%
EUROPE AC
SIMV
SIMV-PSV
PSV
PCV
62 %
3 %
9 %
1 %
15 %
AC
SIMV
SIMV-PSV
PSV
PCV
57 %
2 %
6 %
2 %
23 %
AC
----
SIMV-PSV
PSV
PCV
57 %
5 %
4 %
23 %
DAY 1 DAY 4 DAY 7
MODES OF VENTILATION

11. Esteban A et al.
Chest 2000; 117:1690-1696
ARDS
N = 79
PCV
vs.
CMV
Mortality
Hospital
Relative risk
0.65
(0.46 - 0.96)
Derdak S et al.
Am J Respir Crit Care Med 2002; 166:801-808
ARDS
N = 148
HFOV
vs.
PCV
30 day
Survival
Relative risk
1.14
(0.73 - 1.80)

12. 79 patients with criteria of ARDS
Randomization
PCV (n = 42)
VCV (n =37)
Main outcome
Hospital Mortality
Esteban A, Alía I, Gordo F, et al.
Prospective randomized trial comparing pressure-controlled
ventilation and volume-controlled ventilation in ARDS
Chest 2000; 117:1690-1696

13. Ventilator Modes
Esteban et al Chest 2000; 117:1690

14. UNIVARIATE ANALYSIS
O R CI 95 %
AGE ≥ 65 a. 1’57 1’13 – 2’17
SAPS II ≥ 40 1’63 1’15 – 2’32
≥ 2 ORGAN FAILURE 2’31 1’38 – 3’85
RENAL FAILURE 1’76 0’98 – 3’17
COAGULOPATHY 1’36 0’99 – 3’86
V C V 1’53 1’08 – 2’17
A, Esteban, I. Alía, et al.
Chest 2000;117:1690-1696

15. Odds ratio (CI 95 %) p
SAPS II, per point 1.03 (1.00 – 1.05) 0.03
Cardiovascular failure 4.00 (1.87 – 8.86) < 0.001
Hepatic Failure 3.99 (1.35 – 11.81) 0.01
Variables associated to mortality
Multivariate analysis

16. 39
2 12 12 12 6 9 6
2
60
6 12 6 7 4
3
0
10
20
30
40
50
60
C MV S IMV S IMV-
PS V
PS V PC V PR VC B IPAP NIV Other
Overall population
1998 2004

17. CMV, AMV, SIMV, HFV
PS, PRV, PCV, VCV
ACPRV, FLOW BY, CPAP

18. VENTILATORY MODE SIMV
START TO BE USED ............................. 1970
FIRST PUBLICATION
Intermittent mandatory ventilation
A new approach to weaning patients
from mechanical ventilation
J. B. Downs, EF Klem et al
Chest 64:331.................................... 1973

19. PRESSURE SUPPORT VENTILATION
START TO BE USED ................................. 1980
FIRST PUBLICATIONS
M.J. Banner, R.R. Kirby
Crit Care Med 13;997-998 ................... 1985
O. Prakash, S. Meij
Chest 88;403-408 ................................. 1985

20. Topics to solve…
 There is some mode of ventilation
superior or better than other?
 What is the optimal tidal volume?
 What is the “best” PEEP?
 How we can optimize patient–ventilator
interaction?
 When to think that the NIV has failed?
 When it is necessary to use adjunctive
therapies (eg. prone position) in the
ARDS?

21. Topics to solve…
 There is some mode of ventilation
superior or better than other?
 What is the optimal tidal volume?
 What is the “best” PEEP?
 How we can optimize patient–ventilator
interaction?
 When to think that the NIV has failed?
 When it is necessary to use adjunctive
therapies (eg. prone position) in the
ARDS?

22. New Modes
 Volume Assured Pressure Support
 Pressure Regulated Volume Control/ Volume Support
 Proportional Assist Ventilation
 Automatic Tube Compensation
 Adaptive Support Ventilation
 Airway Pressure Release Ventilation/ Bi-level
Pressure Ventilation

24. N = 4968
22 %
Excluded patients because they were
ventilated with other modes that A/C or SIMV
N = 1681
N = 3287
N = 1969
37 % 21 % 42 %
Patients
ventilated only
with SIMV-PSV
N = 350
Patients initially
ventilated with
SIMV-PSV and
switched to A/C
N = 54
Patients
ventilated only
with A/C
N = 1228
Patients initially
ventilated with
A/C and switched
to SIMV-PSV N
= 54
Crude (non-adjusted) Intensive Care Unit Mortality
Excluded patients because they were
ventilated with a combination of more than
2 modes including A/C and SIMV
N = 1318

25. Patients ventilated with SIMV - PS 367
Patients ventilated with A/C 1.228
PRIMARY OUTCOME was in hospital mortality
After adjustment for propensity score, the overall
effect of SIMV - PS was not significant.
Odds ratio 1.04;95% CI 0.77-1.42 p= .78
G. Ortiz, F. Frutos-vivar et al.
Chest 2010 (in press)

26. Factors Associated with Ventilation Using SIMV-PS:
Univariate and Multivariate Logistic-Regression Analysis
Univariate Analysis Multivariate analysis
Odds Ratio (95% CI) P value Odds Ratio (95% CI) P value
Geographic area
• Latin America
• Europe
• United States and Canada
• Other (Saudi Arabia, Tunisia, Turkey)
1
1.76 (1.32 - 2,53)
4.25 (3.07 - 5.88)
8.13 (4.77 - 13.87)
<.001
1
1.64 (1.12 - 2.40)
3.41 (2.40 - 4.83)
8.58 (4.77 - 15.44)
<.001
Simplified acute physiology score II, per
point
0.98 (0-97 - 0-99) <.001 0.99 (0-98 - 0.99) .02
Main reason for mechanical ventilation
• COPD
• Asthma
• Coma
• Acute respiratory failire
Postopoerative
Sepsis
Pneumonia
Congestive heart failure
Trauma
0.59 (0.31 - 1.13)
0.20 (0.03 - 1.38)
0.48 (0.36 - 0.63)
2.46 (2.06 - 2.93)
0.69 (0.48 - 1.01)
0.66 (0.44 - 1.00)
0.62 (0.36 - 1.09)
2.51 (1.98 - 3.19)
.09
.06
<.001
.001
.05
.04
.08
<.001
---
0.12 (0.02 - 0.94)
0.56 ( 80.38 - 0.82)
2.58 (1.85 - 3.60)
--
--
--
3.59 (2.09 - 6.18)
--
.04
.003
<.001
--
--
--
<.001

27. Factors Associated with Ventilation Using SIMV-PS:
Univariate and Multivariate Logistic-Regression Analysis
Univariate Analysis Multivariate analysis
Odds Ratio (95% CI) P value Odds Ratio (95% CI) P value
Complications during the mechanical
ventilation
• ARDS
• Sepsis
• Ventilator associated pneumonia
• Cardiovascular failure
• Respiratory failure
• Hematologic failure
0.21 (0.07 - 0.63)
0.21 (0.09 - 0.49)
0.40 (0.18 - 0.86)
0.49 (0.38 - 0.65)
0.57 (0.45 - 0.72)
0.46 (0.26 - 0.81)
.001
<.001
.009
<.001
<.001
.003
---
0.28 (0.11 - 0.73)
---
0.66 (0.46 - 0.94)
---
---
--
.009
--
.02
--
--

28. Cases
N = 234
Controls
N = 234
P
value
Days of mechanical ventilation,
median (interquartile range)
3 (2, 5) 3 (2,6) 0,61
Days of weaning,
median (interquartile range)
1 (1, 2) 1 (1,2) 0.28
Reintubation, n (%) 100/140 (7) 101/139 (7) 0.99
Tracheostomy, n (%) 46 (20) 25 (11) 0.007
Lengh of stay in the intensive
care unit, median (interquartile
range)
6 (3, 14) 6 (3, 12) 0.11
Mortality in the intensive care
unit, n (%)
65 (28) 78 (33) 0.19
Lengh of stay in the hospital,
median (interquartile range)
18 (11, 38) 17 (8, 31) 0.05
Mortality in the hospital, n (%) 81 (35) 90 (38) 0.50
Outcomes of patients included in the matched-case study

30.  Preservation of spontaneous breathing
 It may have important effects on VILI (not proven)
 Better cardiac output and oxygen delivery
Improvements in gas exchange
 Reduction in overall sedation requirements
APRV - Advantages

31. Putensen,
AJRCCM 2001;164:43
APRV - What is The Evidence
 Six studies (740 patients) and 2 RCT
 Most of the studies are small case series or cross-over
studies with surrogates of outcome or physiologic
endpoints such as oxygenation.
 One RCT enrolled 30 trauma patients with ARDS, APRV
with SB vs PC time cycled ventilation with sedation
and paralysis for 72 hours. Weaning in both group was
performed on APRV.

32. 4968 Patients
563 (11.3 %) patients
were ventilated at least
one day with
APRV/BIPAP
1228 (24.7 %)
were ventilated
with AC all the time
234 patients
were ventilated all
the time with
APRV/BIPAP
234 were ventilated
with AC
Study Patients Controls

33. APRV - Discussion
 APRV/BIPAP were in a minority of patients (5.2 %).
 The major outcomes in a heterogeneous population of
mechanicaly ventilated patients were similar when
they are ventilated with APRV/BIPAP or with AC.
 The upper airway pressure was lower than peak airway
pressure and the low pressure was higher than PEEP.
 There was a lack of improvement in gas exchange
(may be to different population).
 The proportion of patients the received sedatives were
similar between the group.

34. Outcomes
 There were no differences in the proportion of patients
that received sedatives (73% in the APRV/BIPAP vs. 79
% in the AC group, p=0.08) or neuromuscular blocking
(11 % vs 9%; p=0.47)
 We excluded the 29 patients who received a
neuromuscular blocking agent irrespective of the
number of doses and did not change the results of the
outcome

35. Outcomes
Cases
N = 263
Controls
N = 263
P value
Reintubation, n (%) 10/147 (6.5 %) 7/142 (5%) 0.50
Tracheostomy, n (%) 54 (21 %) 29 (11 %) 0.003
Lenght of stay in the
hospital, median
(interquartile range)
19 (11, 38) 17 (8, 33) 0.06
Mortality in the
hospital, n (%)
92 (35 %) 105 (40 %) 0.23

36. • Non Invasive Mechanical Ventilation

37. A. Esteban, A. Anzueto, I. Alía et al
JAMA 2002;287:345-355
ARF INVASIVE VENTILATION.......... 31 % (p=0.01)
Mortality
COPD-NIV-SUCCESSFUL................... 9.5 %
COPD-NIVINTUBATED...................... 27.3 %
COPD INVASIVE VENTILATION....... 23.8 % (p=0.91)
ARF-NIV-SUCCESSFUL...................... 16.8 %
ARF-NIV-INTUBATED......................... 48.1 %

38. Ram FS et al. (COPD and Mortality)
Cochrane Database Syst Rev. 2004;(3):CD004104.
Bott 1993 0.33 (0.10 – 1.11)
Servillo 1994 1.00 (0.08 – 11.93)
Brochard 1995 0.33 (0.11 – 0.93)
Celikel 1998 0.33 (0.01 – 7.56)
Avdeev 1998 0.33 (0.10 – 1.11)
Plant 2000 0.50 (0.26 – 0.95)
Conti 2002 1.36 (0.48 – 3.86)
Dikensoy 2002 0.50 (0.05 – 5.01)
Khihari 2002 1.50 (0.28 – 8.04)
POOLED RESULTS 0.52 (0.35 – 0.76)
Relative Risk
1 5 10.1 .2
Favors NIV Favors Conventional

39. Keenan SP et al. (ARF and Mortality)
Crit Care Med 2004; 32:2516-2523
Confalonieri 1999
Antonelli 2000
Hilbert 2001
Auriant 2001
Keenan 2002
POOLED RESULTS
-1.0 -0.5 0 0.5 1.0
Absolute Risk Reduction
Favors NIV Favors Control

40. 16,5
4
7
44
10
27
0
10
20
30
40
50
60
COPD ARF CHF
1998
2004
Use of non-invasive ventilation
(ICU Participant in both studies)

41. All – NIV Repeat ICUs
1998
n=256
2004
n=479
1998
n=61
2004
n=186
p
value
Arterial Blood Cases
Prior to NIV
• pH, mean (SD) 7.31 (0.09) 7.32 (0.1) 7.31 (0.09) 7.32 (0.1) 0.73
• PaCO2, mean (SD) 56 (21) 52 (21) 58 (23) 53 (22) 0.23
 PaO2/FiO2, mean (SD) 162 (73) 171 (94) 172 (33) 175 (90) 0.8
Day 1 after NIV
• pH, mean (SD) 7.37 (0.08) 7.34 (0.09) 7.35 (0.09) 7.34 (0.1) 0.49
• PaCO2, mean (SD) 50 (18) 50 (19) 53 (21) 51 (21) 0.57
 PaO2/FiO2, mean (SD) 200 (76) 191 (95) 194 (92) 211 (77) 0.20

42. All – NIV Repeat ICUs
1998
n=256
2004
n=479
1998
n=161
2004
n=186
p
value
Arterial Blood Cases
Prior to NIV
• pH, mean (SD) 7.31 (0.09) 7.32 (0.1) 7.31 (0.09) 7.32 (0.1) 0.73
• PaCO2, mean (SD) 56 (21) 52 (21) 58 (23) 53 (22) 0.23
 PaO2/FiO2, mean (SD) 162 (73) 171 (94) 172 (33) 175 (90) 0.8
Day 1 after NIV
• pH, mean (SD) 7.37 (0.08) 7.34 (0.09) 7.35 (0.09) 7.34 (0.1) 0.49
• PaCO2, mean (SD) 50 (18) 50 (19) 53 (21) 51 (21) 0.57
 PaO2/FiO2, mean (SD) 200 (76) 191 (95) 194 (92) 211 (77) 0.20

43. N I V utilization
1998
N = 161
2004
N = 186
p value
Chronic obstructive
pulmonary disease
22 / 133(16.5%) 40 / 113 (35 %) <0.001
Asthma 1 / 13 (8 %) 7 / 28 (25 %) 0.38
Congestive heart
failure
10 / 152 (7 %) 18 / 105 (17 %) <0.001
Acute respiratory
failure
21 / 373 (6 %) 44 / 446 (10 %) 0.03
● Acute respiratory
distress syndrome
4 / 67 (6 %) 8 / 65 (12 %) 0.19
● Pneumonia 16 / 183 (9 %) 20 / 2006 (15 %) 0.08
● Sepsis 1 / 123 (1 %) 6 / 175 (3 %) 0.25

44. Invasive
ventilation
n=162
Successful
NIV
n=78
Failure NIV
n=27
p
Hours NIV
median (IQR)
48 (21, 98) 16 (6, 30) < 0.001
Days of MV
median (IQR)
4 (2, 9) 3 (2, 5) 5 (3, 15)* 0.01
Tracheostomy, % 15% -- 11% 0.002
Length of stay ICU
median (IQR)
9 (5, 15) 5 (3, 8) 11 (5, 21) <0.001
Length of stay
hospital
median (IQR)
15 (10, 27) 17 (9, 22) 20 (11, 32) 0.25
ICU Mortality, % 23% 9% 41% 0.001
Hospital Mortality, % 32% 17% 54% 0.001

45. All – NIV Repeat ICUs
1998
n=256
2004
n=479
1998
n=161
2004
n=186
p
value
Need for intubation
(failure NIV)
32 % 40 % 31 % 35 % 0.59
Mortality
(failed NIV)
42 % 47 % 47 % 47 % 0.98
COPD 27 % 41 % 50 % 47 % 0.73
ARF 48 % 50 % 46 % 54 % 0.63
Mortality
(successful NIV)
14 % 14 % 21 % 10 % 0.08
COPD 9 % 9 % 12.5 % 3 % 0.24
ARF 17 % 15 % 27 % 15 % 0.21

46. All – NIV Repeat ICUs
1998
n=256
2004
n=479
1998
n=161
2004
n=186
p
value
Need for intubation
(failure NIV)
32 % 40 % 31 % 35 % 0.59
Mortality
(failed NIV)
42 % 47 % 47 % 47 % 0.98
COPD 27 % 41 % 50 % 47 % 0.73
ARF 48 % 50 % 46 % 54 % 0.63
Mortality
(successful NIV)
14 % 14 % 21 % 10 % 0.08
COPD 9 % 9 % 12.5 % 3 % 0.24
ARF 17 % 15 % 27 % 15 % 0.21

47. Conclusions
 The use of NIV in the ICU has doubled
from 1998 to 2004 for all causes of
acute respiratory failure.
 The strong concordance of predicted
and observed practice changes
suggest that clinical trials have
influenced usual care over time.

48. Mechanical ventilation is useful
to “buy” time….
Meanwhile:
 To avoid to injury the lung (barotrauma,
volutrauma, atelectrauma..)
 To avoid the organ dysfunction
 To avoid the muscular atrophy
 To avoid the nosocomial infections