Pathophysiology of mechanical ventilation cairo program dec 2011
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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.
Pathophysiology of mechanical ventilation cairo program dec 2011
- 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
- 29. Fact ! Each lung has a tendency to collapse
- 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
- 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
- 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
- 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