1
|
Ceccato A, Russo A, Barbeta E, Oscanoa P, Tiseo G, Gabarrus A, Di Giannatale P, Nogas S, Cilloniz C, Menichetti F, Ferrer M, Niederman M, Falcone M, Torres A. Real-world corticosteroid use in severe pneumonia: a propensity-score-matched study. Crit Care 2021; 25:432. [PMID: 34915895 PMCID: PMC8674860 DOI: 10.1186/s13054-021-03840-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/24/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide despite correct antibiotic use. Corticosteroids have long been evaluated as a treatment option, but heterogeneous effects on survival have precluded their widespread implementation. We aimed to evaluate whether corticosteroids might improve clinical outcomes in patients with severe CAP and high inflammatory responses. STUDY DESIGN AND METHODS We analyzed two prospective observational cohorts of patients with CAP in Barcelona and Rome who were admitted to intensive care with a high inflammatory response. Propensity score (PS) matching was used to obtain balance among the baseline variables in both groups, and we excluded patients with viral pneumonia or who received hydrocortisone. RESULTS Of the 610 patients admitted with severe CAP, 198 (32%) received corticosteroids and 387 had major criteria for severe CAP. All patients had a baseline serum C-reactive protein above 15 mg/dL. Patients who received corticosteroids were more commonly male, had more comorbidities (e.g., cancer or chronic obstructive pulmonary disease), and presented with significantly higher sequential organ failure assessment scores. Eighty-nine patients met major severity criteria (invasive mechanical ventilation and/or septic shock) and were matched per group. Twenty-eight-day mortality was lower among patients receiving corticosteroids (16 patients, 18%) than among those not receiving them (28 patients, 31%; p = 0.037). After PS matching, corticosteroid therapy reduced the 28-day mortality risk in patients who met major severity criteria (hazard ratio (HR) 0.53, 95% confidence interval (CI) 0.29-0.98) (p = 0.043). In patients who did not meet major severity criteria, no benefits were observed with corticosteroid use (HR 0.88 (95%CI 0.32-2.36). CONCLUSIONS Corticosteroid treatment may be of benefit for patients with CAP who have septic shock and/or a high inflammatory response and requirement for invasive mechanical ventilation. Corticosteroids appear to have no impact on mortality when these features are not present.
Collapse
Affiliation(s)
- A Ceccato
- Ciber de Enfermedades Respiratorias (Ciberes, CB06/06/0028), Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona (UB), Barcelona, Spain
| | - A Russo
- Department of Public Health and Infectious Diseases, Policlinico Umberto I, "Sapienza" University of Rome, Rome, Italy
| | - E Barbeta
- Ciber de Enfermedades Respiratorias (Ciberes, CB06/06/0028), Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona (UB), Barcelona, Spain
- Department of Pneumology, Institut Clinic de Respiratori, Hospital Clinic of Barcelona, Villarroel 170, 08036, Barcelona, Spain
| | - P Oscanoa
- Ciber de Enfermedades Respiratorias (Ciberes, CB06/06/0028), Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona (UB), Barcelona, Spain
- Department of Pneumology, Institut Clinic de Respiratori, Hospital Clinic of Barcelona, Villarroel 170, 08036, Barcelona, Spain
| | - G Tiseo
- Infectious Diseases Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - A Gabarrus
- Ciber de Enfermedades Respiratorias (Ciberes, CB06/06/0028), Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona (UB), Barcelona, Spain
- Department of Pneumology, Institut Clinic de Respiratori, Hospital Clinic of Barcelona, Villarroel 170, 08036, Barcelona, Spain
| | - P Di Giannatale
- Department of Medical, Oral and Biotechnological Sciences, School of Medicine and Health Sciences, Section of Anesthesia Analgesia, Perioperative and Intensive Care, SS. Annunziata Hospital, Gabriele d'Annunzio University of Chieti-Pescara, Chieti, Italy
| | - S Nogas
- Dipartimento Scienze Chirurgiche E Diagnostiche Integrate (DISC), Università Degli Studi Di Genova, Genova, Italy
| | - C Cilloniz
- Ciber de Enfermedades Respiratorias (Ciberes, CB06/06/0028), Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona (UB), Barcelona, Spain
- Department of Pneumology, Institut Clinic de Respiratori, Hospital Clinic of Barcelona, Villarroel 170, 08036, Barcelona, Spain
| | - F Menichetti
- Infectious Diseases Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - M Ferrer
- Ciber de Enfermedades Respiratorias (Ciberes, CB06/06/0028), Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona (UB), Barcelona, Spain
- Department of Pneumology, Institut Clinic de Respiratori, Hospital Clinic of Barcelona, Villarroel 170, 08036, Barcelona, Spain
| | - M Niederman
- Division of Pulmonary and Critical Care Medicine, Weill Cornell Medical College, New York Presbyterian/Weill Cornell Medical Center, New York, NY, USA
| | - M Falcone
- Infectious Diseases Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - A Torres
- Ciber de Enfermedades Respiratorias (Ciberes, CB06/06/0028), Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona (UB), Barcelona, Spain.
- Department of Pneumology, Institut Clinic de Respiratori, Hospital Clinic of Barcelona, Villarroel 170, 08036, Barcelona, Spain.
| |
Collapse
|
2
|
Bordon J, Slomka M, Gupta R, Furmanek S, Cavallazzi R, Sethi S, Niederman M, Ramirez JA. Hospitalization due to community-acquired pneumonia in patients with chronic obstructive pulmonary disease: incidence, epidemiology and outcomes. Clin Microbiol Infect 2019; 26:220-226. [PMID: 31254714 DOI: 10.1016/j.cmi.2019.06.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 06/08/2019] [Accepted: 06/17/2019] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Community-acquired pneumonia (CAP) is an important complication in patients with chronic obstructive pulmonary disease (COPD). This study aimed to define incidence, and outcomes of COPD patients hospitalized with pneumonia in the city of Louisville, and to estimate the burden of disease in the US population. METHODS This was a secondary analysis of a prospective population-based cohort study of residents in Louisville, Kentucky, 40 years old and older, from 1 June 2014 to 31 May 2016. All adults hospitalized with CAP were enrolled. The annual incidence of pneumonia in COPD patients in Louisville was calculated and the total number of adults with COPD hospitalized in the United States was estimated. Clinical outcomes included time to clinical stability (TCS), length of hospital stay (LOS) and mortality. RESULTS From a Louisville population of 18 246 patients with COPD, 3419 pneumonia hospitalizations were documented during the 2-year study. The annual incidence was 9369 patients with pneumonia per 100 000 COPD population, corresponding to an estimated 506 953 adults with COPD hospitalized due to pneumonia in the United States. The incidence of CAP in patients without COPD was 509 (95% CI 485-533) per 100 000. COPD patients had a median (interquartile range) TCS and LOS of 2 (1-4) and 5 (3-9) days respectively. The mortality of COPD patients during hospitalization, at 30 days, 6 months and 1 year was 193 of 3419 (5.6%), 400 of 3374 (11.9%), 816 of 3363 (24.3%) and 1104 of 3349 (33.0%), respectively. CONCLUSIONS There was an annual incidence of 9369 cases of hospitalized CAP per 100 000 COPD patients in the city of Louisville. This was an approximately 18-fold greater incidence of CAP in COPD patients than in those without COPD.
Collapse
Affiliation(s)
- J Bordon
- Providence Health Center, Section of Infectious Diseases, Washington, DC, USA.
| | - M Slomka
- University of Maryland Medical Center, Division of Infectious Diseases, Baltimore, MD, USA
| | - R Gupta
- Cleveland Clinic, Department of Medicine, Division of Hematology and Oncology, Cleveland, OH, USA
| | - S Furmanek
- University of Louisville, Department of Medicine, Division of Infectious Diseases, Louisville, KY, USA
| | - R Cavallazzi
- University of Louisville, Department of Medicine, Division of Pulmonary, Critical Care, and Sleep Disorders, Louisville, KY, USA
| | - S Sethi
- University at Buffalo, Jacobs School of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, Buffalo, NY, USA
| | - M Niederman
- Weill Cornell Medical College, Pulmonary and Critical Care Medicine, New York, NY, USA
| | - J A Ramirez
- University of Louisville, Department of Medicine, Division of Infectious Diseases, Louisville, KY, USA
| | | |
Collapse
|
3
|
Menendez R, Cavalcanti M, Reyes S, Mensa J, Martinez R, Marcos MA, Filella X, Niederman M, Torres A. Markers of treatment failure in hospitalised community acquired pneumonia. Thorax 2008; 63:447-52. [DOI: 10.1136/thx.2007.086785] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
4
|
Eldon M, Corkery K, Gribben D, Fink J, Niederman M. NKTR-061 (inhaled amikacin) delivers high lung doses in mechanically ventilated patients with pneumonia and in healthy subjects. Crit Care 2008. [PMCID: PMC4088413 DOI: 10.1186/cc6263] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
5
|
Lode H, Allewelt M, Balk S, De Roux A, Mauch H, Niederman M, Schmidt-Ioanas M. A prediction model for bacterial etiology in acute exacerbations of COPD. Infection 2007; 35:143-9. [PMID: 17565454 DOI: 10.1007/s15010-007-6078-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Accepted: 02/26/2007] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Bacteria play a leading role in acute exacerbations of chronic obstructive pulmonary disease (COPD), but we lack predictors of bacterial etiology. We developed a prediction model for infection with gram-negative enteric bacteria (GNEB) and Pseudomonas aeruginosa. METHODS Clinical presentation, sputum characteristics, microbial sputum patterns, lung function and previous and concomitant medication were prospectively recorded in patients with moderate to severe exacerbation of COPD. Risk factors for a specific bacterial etiology were calculated and a prediction model developed. RESULTS A total of 193 patients with acute exacerbation were included. In 121 (62.6%) of them a microbial etiology could be identified, most frequently Haemophilus influenzae (32 strains), Streptococcus pneumoniae (22 strains) and P. aeruginosa (12 strains). Multivariate analysis identified severe airflow obstruction and use of systemic steroids as predictors for exacerbation due to gram-negative enteric bacilli and P. aeruginosa. A prediction model including FEV1 < 35% of predicted value, systemic steroid use and prior antibiotic therapy within preceeding 3 months had a negative predictive of 89%, being a helpful tool in excluding patients at risk of exacerbation due to gram-negative enteric bacilli and P. aeruginosa when all criteria are absent. CONCLUSION A simple prediction model based on three factors may identify COPD patients at low risk for exacerbations with gram-negative enteric bacilli and P. aeruginosa. Bacterial Etiology in COPD Exacerbations.
Collapse
Affiliation(s)
- H Lode
- Helios Klinikum Emil von Behring, affiliated Free University Berlin, Chest Hospital Heckeshorn (Infectious Disease and Immunology), Zum Heckeshorn 33, 14109, Berlin, Germany.
| | | | | | | | | | | | | |
Collapse
|
6
|
Niederman M, Chastre J, Corkery K, Fishman R, Fink J, Luyt C, Sanchez M. Decrease in intravenous antibiotic use with adjunctive aerosolized amikacin treatment in intubated mechanically ventilated patients with Gram-negative pneumonia. Crit Care 2007. [PMCID: PMC4095151 DOI: 10.1186/cc5257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
7
|
Ewig S, de Roux A, Bauer T, García E, Mensa J, Niederman M, Torres A. Validation of predictive rules and indices of severity for community acquired pneumonia. Thorax 2004; 59:421-7. [PMID: 15115872 PMCID: PMC1747015 DOI: 10.1136/thx.2003.008110] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND A study was undertaken to validate the modified American Thoracic Society (ATS) rule and two British Thoracic Society (BTS) rules for the prediction of ICU admission and mortality of community acquired pneumonia and to provide a validation of these predictions on the basis of the pneumonia severity index (PSI). METHOD Six hundred and ninety six consecutive patients (457 men (66%), mean (SD) age 67.8 (17.1) years, range 18-101) admitted to a tertiary care hospital were studied prospectively. Of these, 116 (16.7%) were admitted to the ICU. RESULTS The modified ATS rule achieved a sensitivity of 69% (95% CI 50.7 to 77.2), specificity of 97% (95% CI 96.4 to 98.9), positive predictive value of 87% (95% CI 78.3 to 93.1), and negative predictive value of 94% (95% CI 91.8 to 95.8) in predicting admission to the ICU. The corresponding predictive indices for mortality were 94% (95% CI 82.5 to 98.7), 93% (95% CI 90.6 to 94.7), 49% (95% CI 38.2 to 59.7), and 99.5% (95% CI 98.5 to 99.9), respectively. These figures compared favourably with both the BTS rules. The BTS-CURB criteria achieved predictions of pneumonia severity and mortality comparable to the PSI. CONCLUSIONS This study confirms the power of the modified ATS rule to predict severe pneumonia in individual patients. It may be incorporated into current guidelines for the assessment of pneumonia severity. The CURB criteria may be used as an alternative tool to PSI for the detection of low risk patients.
Collapse
Affiliation(s)
- S Ewig
- Augusta Kranken-Anstalt Bochum, Klinik für Pneumologie, Beatmungsmedizin und Infektiologie, Bochum, Germany
| | | | | | | | | | | | | |
Collapse
|
8
|
Affiliation(s)
- M Kollef
- Pulmonary and Critical Care Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | | |
Collapse
|
9
|
|
10
|
Plouffe J, Schwartz DB, Kolokathis A, Sherman BW, Arnow PM, Gezon JA, Suh B, Anzuetto A, Greenberg RN, Niederman M, Paladino JA, Ramirez JA, Inverso J, Knirsch CA. Clinical efficacy of intravenous followed by oral azithromycin monotherapy in hospitalized patients with community-acquired pneumonia. The Azithromycin Intravenous Clinical Trials Group. Antimicrob Agents Chemother 2000; 44:1796-802. [PMID: 10858333 PMCID: PMC89964 DOI: 10.1128/aac.44.7.1796-1802.2000] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to evaluate intravenous (i.v.) azithromycin followed by oral azithromycin as a monotherapeutic regimen for community-acquired pneumonia (CAP). Two trials of i.v. azithromycin used as initial monotherapy in hospitalized CAP patients are summarized. Clinical efficacy is reported from an open-label randomized trial of azithromycin compared to cefuroxime with or without erythromycin. Bacteriologic and clinical efficacy results are also presented from a noncomparative trial of i.v. azithromycin that was designed to give additional clinical experience with a larger number of pathogens. Azithromycin was administered to 414 patients: 202 and 212 in the comparative and noncomparative trials, respectively. The comparator regimen was used as treatment for 201 patients; 105 were treated with cefuroxime alone and 96 were given cefuroxime plus erythromycin. In the comparative trial, clinical outcome data were available for 268 evaluable patients with confirmed CAP at the 10- to 14-day visit, with 106 (77%) of the azithromycin patients cured or improved and 97 (74%) of the comparator patients cured or improved. Mean i.v. treatment duration and mean total treatment duration (i.v. and oral) for the clinically evaluable patients were significantly (P < 0.05) shorter for the azithromycin group (3.6 days for the i.v. group and 8.6 days for the i.v. and oral group) than for the evaluable patients given cefuroxime plus erythromycin (4.0 days for the i.v. group and 10.3 days for the i.v. and oral group). The present comparative study demonstrates that initial therapy with i.v. azithromycin for hospitalized patients with CAP is associated with fewer side effects and is equal in efficacy to a 1993 American Thoracic Society-suggested regimen of cefuroxime plus erythromycin when the erythromycin is deemed necessary by clinicians.
Collapse
Affiliation(s)
- J Plouffe
- Ohio State University, Columbus, Cleveland, Ohio, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
|
12
|
Sanchez-Nieto JM, Torres A, Garcia-Cordoba F, El-Ebiary M, Carrillo A, Ruiz J, Nuñez ML, Niederman M. Impact of invasive and noninvasive quantitative culture sampling on outcome of ventilator-associated pneumonia: a pilot study. Am J Respir Crit Care Med 1998; 157:371-6. [PMID: 9476845 DOI: 10.1164/ajrccm.157.2.97-02039] [Citation(s) in RCA: 246] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We performed an open, prospective, randomized clinical trial in 51 patients receiving mechanical ventilation for more than 72 h, in order to evaluate the impact of using either invasive (protected specimen brush [PSB] and bronchoalveolar lavage [BAL] via fiberoptic bronchoscopy) or noninvasive (quantitative endotracheal aspirates [QEA]) diagnostic methods on the morbidity and mortality of ventilator-associated pneumonia (VAP). Patients were randomly assigned to two groups: Group A patients (n = 24) underwent QEA, PSB, and BAL; Group B patients (n = 27) underwent only QEA cultures. Empiric antibiotic treatment was given according to the attending physician and was modified according to the results of cultures and sensitivity in Group A using PSB and BAL results and in Group B based upon QEA cultures. Bacteriologic cultures were done quantitatively for EA, PSB, and BAL. Thresholds of > or = 10(5), > or = 10(3), and > or = 10(4) CFU/ml were used for QEA, PSB, and BAL, respectively. Microbial cultures from Group A patients were positive in 16 (67%) BAL samples, 14 (58%) PSB samples, and 16 (67%) QEA samples. In Group B patients, QEA microbial cultures yielded positive results in 20 of 27 (74%) samples. In Group A, there was total agreement between culture results of the three techniques on 17 (71%) occasions. In five (21%) cases, QEA coincided with either BAL or PBS. In only two (8%) cases, QEA cultures did not coincide with either PSB or BAL. No cases of positive BAL or PSB cultures had negative QEA cultures. Initial antibiotic treatment was modified in 10 (42%) patients from Group A and in four (16%) patients from Group B (p < 0.05). The observed crude mortality rate was 11 of 24 (46%) in Group A, and 7 of 27 (26%) in Group B, whereas the adjusted mortality rates (observed crude minus predicted at admission) for Groups A and B were 29 and 10%, respectively. There were no statistically significant differences when comparing crude and adjusted mortality rates of Groups A and B. There were no differences in mortality between both groups when comparing pneumonia, considering together Pseudomonas aeruginosa and Acinetobacter spp. (Group A, 33% versus Group B, 27%). There were no differences between Groups A and B with regard to ICU stay duration and total duration of mechanical ventilation. In this pilot study, the impact of bronchoscopy was to lead to more frequent antibiotic changes with no change in mortality. Further studies with larger population samples are warranted to confirm these findings.
Collapse
Affiliation(s)
- J M Sanchez-Nieto
- Servei de Pneumologia i Al.lèrgia Respiratoria, Departament de Medicina, Universitat de Barcelona, Spain
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Snydman D, Fink M, Niederman M, Reinhart H. Treatment of severe pneumonia in hospitalised patients. Results of a multicentre trial comparing i.v. ciprofloxacin with imipenem/cilastatin. Drugs 1995; 49 Suppl 2:439-41. [PMID: 8549393 DOI: 10.2165/00003495-199500492-00128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- D Snydman
- New England Medical Center, Boston, Massachusetts, USA
| | | | | | | |
Collapse
|
14
|
|
15
|
Abstract
Angiotensin converting enzyme (ACE) is present in the endothelial cells of the normal lung where it converts angiotensin I to angiotensin II and inactivates bradykinin. It has been suggested that during endothelial injury ACE is sloughed into the blood, and that if the alveolar capillary membrane is injured, also into the alveolar lining fluid. Seven patients with adult respiratory distress syndrome (ARDS), were compared to 11 normal control subjects, nine patients with sarcoidosis, and six with idiopathic pulmonary fibrosis. Total, differential cell counts and ACE determinations were performed on bronchoalveolar lavage fluid in the ARDS group. ACE was detectable in the BAL of all but one ARDS patient. It was concluded that BAL ACE is elevated in some ARDS patients, especially those with infectious causes of lung injury. Increased ACE may reflect endothelial damage or local increase in ACE production in response to sepsis.
Collapse
|
16
|
Fein A, Wiener-Kronish JP, Niederman M, Matthay MA. Pathophysiology of the adult respiratory distress syndrome. What have we learned from human studies? Crit Care Clin 1986; 2:429-53. [PMID: 3331557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Clinical studies of ARDS have been successful in determining the most common predisposing clinical disorders and the natural history of this syndrome. Sepsis, gastric aspiration, and major trauma are the most frequently associated high-risk factors. Overall mortality is in the range of 60% to 70%, but is even higher if ARDS is associated with sepsis, severe acidemia, or decreased renal function. It is evident that multisystem failure is responsible for death in many patients, as well as secondary pulmonary and extrapulmonary infections. Pathologic studies have provided descriptive information regarding the acute, subacute, and chronic phases of the syndrome, but little insight into the precise pathogenesis of the initial lung injury or the progressive fibrosing alveolitis and lung destruction that develops in some patients. There has been considerable circumstantial evidence from clinical studies implicating the neutrophil as a potentially important mediator of the early changes in lung endothelial and epithelial permeability. However, not all investigators have found the same alterations in neutrophil function in the circulation or in the lavage from the lungs of patients with ARDS. Also, the heterogeneous etiologies of ARDS make it difficult to be sure that there is a final common pathway for acute lung injury in all ARDS patients. In addition, there are a host of mediators, including products of complement activation and arachidonic acid metabolism, that may be important in amplifying the inflammatory response. Also, abnormalities of surfactant production and collagen turnover, as well as impaired host defenses in the lung, may contribute to the progressive respiratory failure that occurs in some ARDS patients, even though the acute, exudative phase of lung injury has resolved. Future human studies may provide useful information about the mechanisms of the acute lung injury through studies of circulating plasma markers, blood elements, and lavage fluids from high-risk patients. On the other hand, samples of cells and mediators from the airspaces with lavage still may not reflect the critical interactions of mediators and cells with the lung endothelium that lead to the protein-rich pulmonary edema that characterizes the first phase of ARDS. Thus, experimental studies must continue to study the details of the early phases of acute lung injury (see article by Flick, page 455). Finally, it is clear that treatment designed to reduce the severity and the incidence of ARDS must be started early, since the syndrome develops so rapidly in high-risk patients.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- A Fein
- State University of New York, Stony Brook School of Medicine
| | | | | | | |
Collapse
|