330 likes | 457 Views
ALI/ARDS IN SEPSIS. Dr Gül Gürsel Gazi University School of Medicine Department of Pulmonary Diseases. 60% of etiologies in ALI are sepsis Pulmonary source 46%, other source 33% 1. 1 NEJM 2005; 353:1685-93(King County Lung Injury Project-KCLIP) 2 Am J Respir Crit Care Med 1999; 159:1849-61
E N D
ALI/ARDS IN SEPSIS Dr Gül Gürsel Gazi University School of Medicine Department of Pulmonary Diseases
60% of etiologies in ALI are sepsisPulmonary source 46%, other source 33%1 1 NEJM 2005; 353:1685-93(King County Lung Injury Project-KCLIP) 2 Am J Respir Crit Care Med 1999; 159:1849-61 3 Am J Respir Crit Care Med 2000; 165:443-8
The American-European consensus conference criteria for ALI and ARDS • ALI • Acute onset • PaO2/FiO2300 mmHg(regardless of PEEP level) • Bilateral infiltrates • PAOP 18 mmHg or no clinical evidence of left atrial hypertension • ARDS • Acute onset • PaO2/FiO2200 mmHg(regardless of PEEP level) • Bilateral infiltrates • PAOP 18 mmHg or no clinical evidence of left atrial hypertension Am J Resp Crit Care Med 1994;149:818-824
Edema fluid to plasma protein concentrations <0.65transudate in hydrostatic pulmonary edema >0.65exudate in increased permeability pulmonary edema(ALI/ARDS) Matthay MA et al Physiol Rev 2002; 82:569-600
Clinical disorders associated with the development of ALI and ARDS DİRECT LUNG INJURY (PULMONARY) • Aspiration of gastric contents • Pneumonia • Near drowning • Inhalational injuries • Pulmonary contusion • Pulmonary embolic disorders • Reperfusion injury • Thoracic radiotherapy INDIRECT LUNG INJURY (EXTRAPULMONARY) • Sepsis, SIRS • Severe trauma with shock • Acute pancreatitis • Transfusion of blood products • Drug overdose and toxins • Anaphylaxis • ECMO, CAGS • Decompression sickness
Type I(90%), • Type II(10%) alveolar epitelial cells • Capillary endothelial cells • İnterstitium
Problems in ALI ALI=edema+inflammation • Leukocyte recruitment and/or activation • Alveolar epitheal cell damage/alteration • Lung surfactant dysfunction/inactivation • Pulmonary interstitial injury • Inflammatory mediators/factors produced • Microvascular dysfunction • Airway injury • Coagulation abnormalities
Resident and Recruited Cells of The Lung Inflammatory Response
Resident and Recruited Cells of The Lung Inflammatory Response
The role of Toll-like receptors(TLRs) in pulmonary host response • TLR are the first to detect host invasion by pathogens, initiate immune responses and form the crucial link between the innate and adaptive immune systems
The role of Toll-like receptors(TLRs) in pulmonary host response • TLR4 recognizes LPS of gram-negative bacteria and subsequently induces an inflammatory response • Gram-positive PAPMs are all ligans of TLR2 • Lipoteichoic acid • Lipoproteins • peptidoglycan SHOCK 2005; 24:12-18
Role of Surfactant in ALI NEJM 2004; 351:853-855
Endogenous compouns that inhibit lung surfactant activity • Biophysical inhibitors • Plasma en blood proteins(alb, Hb, fibrinogen) • Cell membrane lipids • Lysophospholipids • Fluid free fatty acids • Glycolipids and sphingolipids • Chemically acting inhibitors • Lytic enzymes(proteases, phospholipases) • Reactive oxygen and nitrogen species • Antibodies to surfactant proteins
Apoptosis • Neutrophil apoptosis is inhibited early in ARDS and that the lifespan of neutrophils returns to normal as inflammation resolves • Apoptosis of alveolar epithelial cells by the Fas/Fas ligand system may also be of particular importance in the development of the permeability changes Critical Care 2003; 7: 355-8
Am J Respir Cell Moll Biol 2005; 33:319-327 Mutlu G, Am J Respir Crit Care Med 2004;170:1270-1275
The influence of preexisting inflammation • During severe inflammation such as sepsis immune response follows a biphasic pattern • Overwhelming proinflammatory response leads to tissue injury • Excessive activation of antiinflammatory pathways results in impaired pulmonary host defence • Dysfunctional mononuclear cells • Apoptosis of immune cells • Production of anti-inflammatory cytokines such as IL-10
Local pulmonary host defense during respiratory tract infections is influenced by sepsis or sepsis like sydromes • J Immunol 1999; 162:392-399 • J Immunol 2000; 165:6496-6503 • Shock 2004; 21:415-425 Incidence of VAP in ARDS =60% • Am J Respir Crit Care Med 1997;156:1092-8
Angiotensin-converting enzyme and ALI • Angiotensin-converting enzyme(ACE) has been identified as the functional receptor for SARS-CoV • Wenhui Li NATURE 2003; 426:450-454 • Mice deficient for ACE showed markedly improved disease and recombinant ACE2 can protect mice from severe acute lung injury • NATURE 2005;436:112-6 • ACE polymorfism is a significant prognostic factor for the outcome of ARDS • Crit Care Med 2006;34:1001-6