Small Airway Chronic Obstructive Disease Syndrome Following Exposure to WTC Dust

Details

• Personal Author:
  Berger KI ; Reibman J
• Description:
  This study evaluated small airway function at rest and during exercise to uncover mechanisms for exertional dyspnea that persists despite high dose chronic therapy and despite presence of normal airflow on spirometry. The data demonstrated: 1) Small airway dysfunction was present at rest in persistently symptomatic subjects to a degree that was more pronounced as compared with an asymptomatic control group; 2) Despite chronic ICS/LABA therapy, residual reversibility of the small airway dysfunction was demonstrable following inhalation of a LAMA; 3) Exertional dyspnea was reproduced during exercise in symptomatic patients testing to a degree that was more pronounced as compared with an asymptomatic control group; 4) numerous mechanisms for exertional dyspnea were uncovered by specific assessment of small airway function during and following exercise including expiratory flow limitation during tidal breathing, dynamic hyperinflation and small airway hyperreactivity. The observed findings indicate that monitoring for occupational and/or environmental lung injury should be modified to include assessment of small airway function in addition to routine spirometry. This conclusion is based on the concept that spirometry may identify airway injury as a reduction in lung volume or air flow, however, spirometry can often be normal even in symptomatic patients, particularly when injury is located in the distal airways. Prior data from our program has demonstrated an association between presence of small airway dysfunction and presence of new onset and persistent respiratory symptoms following exposure to inhaled toxins caused by the collapse of the World Trade Center on September 11, 2001. The present study extends these observations by establishing a direct link between exertional dyspnea and simultaneous enhancement of small airway dysfunction. We further demonstrate that these findings may occur despite chronic high dose therapy with ICS and LABA medications. A key finding in the present study is that many individuals demonstrate residual reversibility upon administration of a single dose of a LAMA. It must be emphasized that the presence and reversibility of these small airway abnormalities were only demonstrable by oscillometry during tidal breathing, but they were not apparent from spirometry assessment of maximal expiratory airflow during forced exhalation. These studies build upon prior histologic and functional evidence for distal airway abnormalities as a manifestation of obstructive lung diseases. Thus, characterization of distal airway injury in addition to standard spirometry is crucial in determination of both optimal medical therapy and assessment of changes over time. Moreover, identification of distal airway injury may be an early marker of disease that may be progressive but may also be amenable to therapy. It is anticipated that the results of our studies may have impacts on several areas of occupational and environmental respiratory health. First, our data support additional of oscillometry to routine spirometry to monitor for inhalational lung injury in at-risk populations. Our data clearly establish that this change will allow identification of small airway disease at a time point prior to development of impaired airflow on spirometry. Second, the data indicate that therapy for symptomatic patients should consider use of a broad range of medications in addition to ICS and LABA. Lastly, longitudinal monitoring will be enhanced by inclusion of small airway metrics to establish improvement in respiratory health. [Description provided by NIOSH]
• Subjects:
  Dust Lung Lung Diseases Occupational Health Particulate Matter Respiratory Function Tests Respiratory System Respiratory Tract Diseases Safety September 11 Terrorist Attacks
• Keywords:
  Dust Exposure Dust Inhalation Lung Disorders Particulate Dust Physical Exercise Respiratory Function Spirometry World Trade Center WTC
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Final Cooperative Agreement Report
• Place as Subject:
  New York ; OSHA Region 2
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-31
• NIOSHTIC Number:
  nn:20067575
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, U01-OH-011317, 2020 Nov; :1-31
• Contact Point Address:
  Kenneth Berger, MD, 240 East 38th St, Room M-15, New York, NY 10016
• Email:
  kenneth.berger@nyumc.org
• Federal Fiscal Year:
  2021
• Performing Organization:
  New York University School of Medicine
• Peer Reviewed:
  False
• Start Date:
  20160901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20190831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:d20fea4784f4d482aca587d5d5d08069d86df5785e7ec87192c6591a76f2989f5cd653dc6939e792810653228e59a3978c1fd75763d7ef0764373aba16f86148
• Download URL:
  https://stacks.cdc.gov/view/cdc/219201/cdc_219201_DS1.pdf
• File Type:
  [PDF - 1.84 MB ]