scispace - formally typeset
Search or ask a question
Author

Leonard D. Hudson

Bio: Leonard D. Hudson is an academic researcher from University of Washington. The author has contributed to research in topics: ARDS & Lung injury. The author has an hindex of 62, co-authored 143 publications receiving 18625 citations. Previous affiliations of Leonard D. Hudson include Harborview Medical Center & Emory University.


Papers
More filters
Journal ArticleDOI
TL;DR: It is estimated that each year in the United States there are 190,600 cases of acute lung injury, which are associated with 74,500 deaths and 3.6 million hospital days, considerably higher than previous reports have suggested.
Abstract: BACKGROUND Acute lung injury is a critical illness syndrome consisting of acute hypoxemic respiratory failure with bilateral pulmonary infiltrates that are not attributed to left atrial hypertension. Despite recent advances in our understanding of the mechanism and treatment of acute lung injury, its incidence and outcomes in the United States have been unclear. METHODS We conducted a prospective, population-based, cohort study in 21 hospitals in and around King County, Washington, from April 1999 through July 2000, using a validated screening protocol to identify patients who met the consensus criteria for acute lung injury. RESULTS A total of 1113 King County residents undergoing mechanical ventilation met the criteria for acute lung injury and were 15 years of age or older. On the basis of this figure, the crude incidence of acute lung injury was 78.9 per 100,000 person-years and the age-adjusted incidence was 86.2 per 100,000 person-years. The in-hospital mortality rate was 38.5 percent. The incidence of acute lung injury increased with age from 16 per 100,000 person-years for those 15 through 19 years of age to 306 per 100,000 person-years for those 75 through 84 years of age. Mortality increased with age from 24 percent for patients 15 through 19 years of age to 60 percent for patients 85 years of age or older (P<0.001). We estimate that each year in the United States there are 190,600 cases of acute lung injury, which are associated with 74,500 deaths and 3.6 million hospital days. CONCLUSIONS Acute lung injury has a substantial impact on public health, with an incidence in the United States that is considerably higher than previous reports have suggested.

3,358 citations

Journal ArticleDOI
TL;DR: A multicenter, randomized controlled trial of corticosteroids in patients with persistent acute respiratory distress syndrome found that methylprednisolone improved survival and biochemical markers of inflammation and fibroproliferation, and infectious complications.
Abstract: Background Persistent acute respiratory distress syndrome (ARDS) is characterized by excessive fibroproliferation, ongoing inflammation, prolonged mechanical ventilation, and a substantial risk of death. Because previous reports suggested that corticosteroids may improve survival, we performed a multicenter, randomized controlled trial of corticosteroids in patients with persistent ARDS. Methods We randomly assigned 180 patients with ARDS of at least seven days' duration to receive either methylprednisolone or placebo in a double-blind fashion. The primary end point was mortality at 60 days. Secondary end points included the number of ventilator-free days and organ-failure–free days, biochemical markers of inflammation and fibroproliferation, and infectious complications. Results At 60 days, the hospital mortality rate was 28.6 percent in the placebo group (95 percent confidence interval, 20.3 to 38.6 percent) and 29.2 percent in the methylprednisolone group (95 percent confidence interval, 20.8 to 39.4 p...

1,138 citations

Journal ArticleDOI
TL;DR: Of the ARDS cases, 76 percent occurred in the initial 24 hours after meeting the criteria, and ARDS did not occur after 72 hours unless there was late development of sepsis (3 of 136 patients).
Abstract: One hundred thirty-six patients meeting our criteria for one or more of eight clinical conditions were prospectively observed for the development of the adult respiratory distress syndrome. A high risk population was identified, including those with sepsis syndrome (38 percent), documented aspiration of gastric contents (30 percent), multiple emergency transfusions (24 percent), and pulmonary contusion (17 percent). The risk from multiple major fractures appeared low but contributed to the risk from other factors. The risk associated with just one factor (25 percent) was compounded by the presence of two (42 percent) and three (85 percent) simultaneous factors, and this finding was more predictive of ARDS than the injury severity score or initial arterial oxygenation. Of the ARDS cases, 76 percent occurred in the initial 24 hours after meeting the criteria. ARDS did not occur after 72 hours unless there was late development of sepsis (3 of 136 patients).

628 citations

Journal ArticleDOI
TL;DR: The molar ratios remained low for 7 d or longer, limiting the activity of soluble IL-1 beta and TNF-alpha in the lungs at the onset of ARDS.
Abstract: Acute respiratory distress syndrome (ARDS) involves an intense inflammatory response in the lungs, with accumulation of both pro- and antiinflammatory cytokines in bronchoalveolar lavage fluid (BALF). Our goal was to determine how the balance between pro- and antiinflammatory mediators in the lungs changes before and after the onset of ARDS. We identified 23 patients at risk for ARDS and 46 with established ARDS and performed serial bronchoalveolar lavage (BAL). We used immunoassays to measure tumor necrosis factor alpha (TNF-alpha) and soluble TNF-alpha receptors I and II; interleukin 1 beta (IL-1 beta), IL-1 beta receptor antagonist, and soluble IL-1 receptor II; IL-6 and soluble IL-6 receptor; and IL-10. We used sensitive bioassays to measure net TNF-alpha, IL-1 beta, and IL-6 activity. Although individual cytokines increased before and after onset of ARDS, greater increases occurred in cognate receptors and/or antagonists, so that molar ratios of agonists/antagonists declined dramatically at the onset of ARDS. The molar ratios remained low for 7 d or longer, limiting the activity of soluble IL-1 beta and TNF-alpha in the lungs at the onset of ARDS. This significant antiinflammatory response early in ARDS may provide a key mechanism for limiting the net inflammatory response in the lungs.

521 citations

Journal ArticleDOI
TL;DR: IL-8 and ENA-78 were the cytokines most strongly and consistently correlated with PMN concentrations in the lung fluids of patients with ARDS, and the correlations were independent of the other cytokines or coexisting lung infection.
Abstract: To determine the relationship between airspace cytokines and cellular inflammatory responses in patients with the acute respiratory distress syndrome (ARDS), we performed bronchoalveolar lavage (BAL) in 82 prospectively identified, mechanically ventilated patients on Days 3, 7, 14, and/or 21 after the onset of ARDS. We studied the relationships between bronchoalveolar lavage fluid (BALF) cell populations and the concentrations of two potent neutrophil (PMN) chemoattractants, interleukin-8 (IL-8) and epithelial cell-derived neutrophil activator-78 (ENA-78); two potent monocyte chemoattractants, monocyte chemotactic peptide-1 (MCP-1) and macrophage inflammatory peptide-1 alpha (MIP-1 alpha); and the early response cytokine interleukin-1 beta (IL-1 beta) and its naturally occurring antagonist, IL-1 receptor antagonist protein (IRAP). We found that all of these cytokines were significantly increased regardless of the duration of ARDS. IL-8 and ENA-78 were the cytokines most strongly and consistently correlated with PMN concentrations in the lung fluids of patients with ARDS, and the correlations were independent of the other cytokines or coexisting lung infection. None of the cytokines tested correlated with macrophage concentrations. MCP-1 was directly correlated with lung injury score on Days 7, 14, and 21. Although neither IL-8 nor ENA-78 was associated with outcome, levels of IL-1 beta measured on Day 7 were associated with an increased risk of death (odds ratio [OR] = 2.8; 95% confidence interval [CI] = 1.1 to 7.4). These data demonstrate potential molecular mechanisms of the persistent inflammatory process in the lungs of patients with ARDS.

519 citations


Cited by
More filters
Journal ArticleDOI
01 Jun 1992-Chest
TL;DR: An American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference was held in Northbrook in August 1991 with the goal of agreeing on a set of definitions that could be applied to patients with sepsis and its sequelae as mentioned in this paper.

12,583 citations

Journal ArticleDOI
20 Jun 2012-JAMA
TL;DR: The updated and revised Berlin Definition for ARDS addresses a number of the limitations of the AECC definition and may serve as a model to create more accurate, evidence-based, critical illness syndrome definitions and to better inform clinical care, research, and health services planning.
Abstract: The acute respiratory distress syndrome (ARDS) was defined in 1994 by the American-European Consensus Conference (AECC); since then, issues regarding the reliability and validity of this definition have emerged. Using a consensus process, a panel of experts convened in 2011 (an initiative of the European Society of Intensive Care Medicine endorsed by the American Thoracic Society and the Society of Critical Care Medicine) developed the Berlin Definition, focusing on feasibility, reliability, validity, and objective evaluation of its performance. A draft definition proposed 3 mutually exclusive categories of ARDS based on degree of hypoxemia: mild (200 mm Hg < PaO2/FIO2 ≤ 300 mm Hg), moderate (100 mm Hg < PaO2/FIO2 ≤ 200 mm Hg), and severe (PaO2/FIO2 ≤ 100 mm Hg) and 4 ancillary variables for severe ARDS: radiographic severity, respiratory system compliance (≤40 mL/cm H2O), positive end-expiratory pressure (≥10 cm H2O), and corrected expired volume per minute (≥10 L/min). The draft Berlin Definition was empirically evaluated using patient-level meta-analysis of 4188 patients with ARDS from 4 multicenter clinical data sets and 269 patients with ARDS from 3 single-center data sets containing physiologic information. The 4 ancillary variables did not contribute to the predictive validity of severe ARDS for mortality and were removed from the definition. Using the Berlin Definition, stages of mild, moderate, and severe ARDS were associated with increased mortality (27%; 95% CI, 24%-30%; 32%; 95% CI, 29%-34%; and 45%; 95% CI, 42%-48%, respectively; P < .001) and increased median duration of mechanical ventilation in survivors (5 days; interquartile [IQR], 2-11; 7 days; IQR, 4-14; and 9 days; IQR, 5-17, respectively; P < .001). Compared with the AECC definition, the final Berlin Definition had better predictive validity for mortality, with an area under the receiver operating curve of 0.577 (95% CI, 0.561-0.593) vs 0.536 (95% CI, 0.520-0.553; P < .001). This updated and revised Berlin Definition for ARDS addresses a number of the limitations of the AECC definition. The approach of combining consensus discussions with empirical evaluation may serve as a model to create more accurate, evidence-based, critical illness syndrome definitions and to better inform clinical care, research, and health services planning.

7,731 citations

Journal ArticleDOI
TL;DR: This work presents a meta-analyses of the immune system’s response to chronic obstructive pulmonary disease and shows clear patterns of decline in the immune systems of elderly patients with compromised immune systems.
Abstract: Lionel A. Mandell, Richard G. Wunderink, Antonio Anzueto, John G. Bartlett, G. Douglas Campbell, Nathan C. Dean, Scott F. Dowell, Thomas M. File, Jr. Daniel M. Musher, Michael S. Niederman, Antonio Torres, and Cynthia G. Whitney McMaster University Medical School, Hamilton, Ontario, Canada; Northwestern University Feinberg School of Medicine, Chicago, Illinois; University of Texas Health Science Center and South Texas Veterans Health Care System, San Antonio, and Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas; Johns Hopkins University School of Medicine, Baltimore, Maryland; Division of Pulmonary, Critical Care, and Sleep Medicine, University of Mississippi School of Medicine, Jackson; Division of Pulmonary and Critical Care Medicine, LDS Hospital, and University of Utah, Salt Lake City, Utah; Centers for Disease Control and Prevention, Atlanta, Georgia; Northeastern Ohio Universities College of Medicine, Rootstown, and Summa Health System, Akron, Ohio; State University of New York at Stony Brook, Stony Brook, and Department of Medicine, Winthrop University Hospital, Mineola, New York; and Cap de Servei de Pneumologia i Allergia Respiratoria, Institut Clinic del Torax, Hospital Clinic de Barcelona, Facultat de Medicina, Universitat de Barcelona, Institut d’Investigacions Biomediques August Pi i Sunyer, CIBER CB06/06/0028, Barcelona, Spain.

5,558 citations

01 Mar 2007
TL;DR: An initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI is described.
Abstract: Acute kidney injury (AKI) is a complex disorder for which currently there is no accepted definition. Having a uniform standard for diagnosing and classifying AKI would enhance our ability to manage these patients. Future clinical and translational research in AKI will require collaborative networks of investigators drawn from various disciplines, dissemination of information via multidisciplinary joint conferences and publications, and improved translation of knowledge from pre-clinical research. We describe an initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI. Members representing key societies in critical care and nephrology along with additional experts in adult and pediatric AKI participated in a two day conference in Amsterdam, The Netherlands, in September 2005 and were assigned to one of three workgroups. Each group's discussions formed the basis for draft recommendations that were later refined and improved during discussion with the larger group. Dissenting opinions were also noted. The final draft recommendations were circulated to all participants and subsequently agreed upon as the consensus recommendations for this report. Participating societies endorsed the recommendations and agreed to help disseminate the results. The term AKI is proposed to represent the entire spectrum of acute renal failure. Diagnostic criteria for AKI are proposed based on acute alterations in serum creatinine or urine output. A staging system for AKI which reflects quantitative changes in serum creatinine and urine output has been developed. We describe the formation of a multidisciplinary collaborative network focused on AKI. We have proposed uniform standards for diagnosing and classifying AKI which will need to be validated in future studies. The Acute Kidney Injury Network offers a mechanism for proceeding with efforts to improve patient outcomes.

5,467 citations

Journal ArticleDOI
TL;DR: This document reflects a process whereby a group of experts and opinion leaders revisited the 1992 sepsis guidelines and found that apart from expanding the list of signs and symptoms of sepsi to reflect clinical bedside experience, no evidence exists to support a change to the definitions.
Abstract: Objective: In 1991, the American College of Chest Physicians (ACCP) and the Society of Critical Care Medicine (SCCM) convened a "Consensus Conference", the goals of which were to provide a conceptual and a practical framework to define the systemic inflammatory response to infection, which is a progressive inju- rious process that falls under the gen- eralized term 'sepsis' and includes sepsis-associated organ dysfunction as well. The general definitions intro- duced as a result of that conference have been widely used in practice, and have served as the foundation for in- clusion criteria for numerous clinical trials of therapeutic interventions. Nevertheless, there has been an impe- tus from experts in the field to modify these definitions to reflect our current understanding of the pathophysiology of these syndromes. Design: Several North American and European inten- sive care societies agreed to revisit the definitions for sepsis and related con- ditions. This conference was spon- sored by the Society of Critical Care Medicine (SCCM), The European So-

5,298 citations