Mechanical ventilation can lead to mortality in trauma and ARDS patients. The basic physiology of ventilation involves the lung skeleton, breathing muscles, and changes in lung mechanics with collapse. Ventilation can lead to volutrauma from high volumes and atelectrauma from low volumes. Surfactant is depleted by the opening and closing of alveoli. This can increase surface tension and promote collapse. Ventilation may also trigger a systemic inflammatory response. Nosocomial pneumonia is a complication that protocols aim to prevent through various measures. Newer ventilation strategies like open lung aim to recruit and keep alveoli open to prevent injury.

1. Pathophysiology of
Mechanical Ventilation
PJ Papadakos MD FCCM FCCP
Director CCM
Professor Anesthesiology, Surgery and Neurosurgery
University of Rochester School of Medicine
Rochester NY
Professor Respiratory Care
State University Of New York Genesee Community
College
Batavia NY

2. 20 year collaboration Rotterdam and now Berlin

3. Funding over the Years:
Siemens
Erasmus University
European Union
Berlin University
Astra Zeneca
BOC
Lilly

5. The Facts on Mortality

6. Dept. of Anesthesiology
mortality rate (%)
Mechanical ventilation
overall ventilated ARDS
Esteban et al. JAMA 2002;
287

7. Dept. of Anesthesiology
Ninety-day mortality
100
80
41.3% 44.2%
60
40
20
0
non-ARDS ARDS
Luhr et al. Intensive Care Med 2000: 26:508-17

8. Basic Physiology
The Base of Good Care
In all trauma patients

9. What do these have in common

11. ARDS Net
Showed that we are mammals!

14. Lung Skeleton

15. Lung Skeleton
 Force-bearing structure
 Elastin and collagen that are embedded in
a the extracellular matrix
 Two fiber systems connected at alveolar
levels one originating from the hilum and
the other from the visceral pleura in the
periphery
Papadakos, Karcz and Lachman Mechanical Ventilation in Trauma, Curr Opin in
Anesthesiol 23 2010

17. Microstructure

19. The Breathing Muscle It Goes up and
Down

20. Chest Expansion
Generating Flow

22. Change in muscle fibers
Type I Type IIa Type Iid/x Type IIb
Slow Fast Fast Fast
Shanely et al. AJRCCM 2002;166:1369-74

23. Controlled mechanical ventilation
Powers et al. JAP 2002;92:1851-8

24. St. Michael’s Hospital
A teaching hospital affiliated with the University of Toronto
Levine et al. NEJM 2008; 358:1327-35

25. 47 Days 3 Days
Knisely et al. J Pediatric 1988;113:1074-7

27. Physiology of Atelectasis

29. Fact !
Each lung has
a tendency to
collapse

31. Decreased Oxgenenation

32. Eskaros and Papadakos Respiratory Monitoring in Millers Anesthesia 7th

33. Lung Mechanics change with Lung Collapse

34. Shear Forces

35. VOLUTRAUMA
trauma from
high lung volumes ATELECTRAUMA (RACE)
trauma from
low lung volumes

39. Pulmonary Surfactant

40. Surfactant
 90% lipids
 10% Proteins
Hydrophilic: SP-A and SP-D
Hydrophobic: SP-B and SP-C

42. Curr Opin Crit Care 10, 2004: 18-22

43. Pulmonary Surfactant was
initially
identified as a lipoprotein
complex that reduces
surface tension at the air-
liquid interface of the lung

46. Lipids
 Levels of total phospholipids decrease
over time with cyclic opening and closing
especially phosphatidylcholine and
phosphatidylglycerol, which are essential
for lowering surface tension at the
alveolar capillary membrane.
Tsangaris l. et al Eur Respir J 2003, 21:495-501

47. The cycle opening and
closing of Alveolar
Units
Deplete Surfactant and lead to
further collapse through clumping.

51. Key to Immunology
And host defence

52. Lung host defence mechanisms the lung is constantly challenged by inhaled pathogen
Pollutants an particles

53. of a family of proteins known as collectins.

56. Surfactant Proteins A and SP-D potentially bind several receptors, including Toll receptors

57. SURFACTANT
INACTIVATION
DECREASED
SURFACTANT
ACTIVITY
HIGH INCREASED
PERMEABILITY SURFACE TENSION
EDEMA AT ALVEOLAR WALL
INCREASED
SUCTION
FORCES ACROSS
ALVEOLAR
WALL

59. Cascade of cytoactive molecules

61. From our Lab in Rotterdam:

63. Dept. of Anesthesiology
Ventilator-associated lung injury
Purine conc BALF (M)
4
3
2
1
0 Surfactant
Control 7/0 45/10 45/0
Verbrugge et al. Crit Care Med

65. Effect of ventilation on renal
100 failure
% of renal failure
entry
75
72-96 h
50 535.9
507.2
280.1
25
14 86 18 18
0
Conventional Protective
ventilation ventilation
(n=22) (n=22)

66. Effect of ventilation on hepatic
failure
% of hepatic failure
40
entry
30
72-96 h
20 535.9
507.2
280.1
10
0 23 9 5
0
Conventional Protective
ventilation ventilation
(n=22) (n=22)

68. A Systemic Inflammatory Process

73. Nosocomial Pneumonia

74. Medicare and Insurance Guidelines

75. Nosocomial Pneumonia
 Head of Bed Up
 Suctioning Mouth and Subglotic
 Mouth Care
 Oral intubation and Special ET tubes
 Hand washing and gowns
 Low gastric volumes
 Humidification

76. Presence of
atelectasis
Leads to impairment of host
defense

promotes nosocomial pneumonia

77. Nosocomial Pneumonia True Protection

78. Many Things Do Not
Work

80. Critical Care Medicine 36, #3: 782-788 2008

81. Lets Jump into some up coming ideas on ventilation

82. Dept. of Anesthesiology
Surfactant Depletion followed by 4 hrs of Mechanical
ventilation
P/F-ratio: P/F -Ratio: 310
650
© B. Lachmann
Open Lung Strategy ARDS Network Protocol

83. ARDSnet Permissive
PEEP table = atelectasis
M.Amato

84. Permissive
Atelectasis

85. Permissive
ARDSnet
atelectasis

86. Permissive
Atelectasis

87. Permissive
ARDSnet
atelectasis

89. PROTETORA
Open Lung

91. Regional Spectrum of Opening Pressures
Opening
Superimposed Pressure
Pressure Inflated 0
Small Airway 10-20 cmH2O
Collapse
Alveolar Collapse
40-60 cmH2O
(Reabsorption)
Consolidation 
(modified from Gattinoni)

94. PEEP
 Is natural
 It keeps recruited units open
 Must be titrated

96. Dept. of Anesthesiology
Healthy Tween
Tween & PEEP
© B. Lachmann
Steinberg et al. Am J Respir Crit Care Med; 2004; 169: 57-63

97. Dept. of Anesthesiology
PEEP levels used in patients on mechanical
ventilation: international data
50
40
Patients (%)
30
20
10
0
0 1 to 5 6 to 10 11 to 15 >15
PEEP (cm H2O)
Esteban et al. Am J Respir Crit Care Med 2000:161:1450-8

98. Barbas et al. Am J Respir Crit Care Med; 2002,

99. Hamdan A. A , Papadakos PJ Saunders Manual of Critical Care 2002

100. Small Positive End-Expiratory Pressure Decrease Results in Dramatic Pa02 Changes
In a Experimental Model of ARDS
Schwaiberger, Lachmann,
Papadakos and Leonhardt
ATS 2011

101. 1998,
VOLUME 338 February, 5 NUMBER 6
NUMBER 6

102. Survival function - Amato et al.
1.0
Cumulative Survival
.8
Protective
.6
P < 0.001
.4
Control
.2
N = 53
0.0
0 10 20 30
Time after Entry ( days )

104. Many Thanks
To my many Friends