Small airway dysfunction as a mechanism for persistence of lower respiratory symptoms despite treatment in patients exposed to World Trade Center dust

Details

• Personal Author:
  Berger KI ; Caplan-Shaw C ; Goldring RM ; Kazeros A ; Pradhan D ; Reibman J
• Description:
  Introduction: Exposure to World Trade Center (WTC) dust resulted in respiratory symptoms (cough, wheeze, dyspnea, chest tightness) in populations of community members exposed to this disaster. Treatment has been applied using a standardized treatment algorithm for asthma based on published guidelines that include use of "controller" therapies for persistent respiratory symptoms. Despite this approach, many patients report continued symptoms and remain on long term high dose ICS and are at risk for the adverse health effects of long term corticosteroid treatment. We hypothesize that WTC dust subjects exposed with persistent lower respiratory symptoms have evidence for either small airways disease and/ or bronchial hyper-responsiveness. Methods: Patients enrolled in the Bellevue Hospital WTC Environmental Health Center (WTC EHC) with physician diagnosis of asthma and therapy with ICS/LA8A were studied. All subjects had normal large airway function as assessed by FEV 1. Subjects were assessed over a 3 month protocol that included measures of drug adherence, symptom control (Asthma Control Test (ACT)), small airway function (forced oscillation testing [FOT]) and bronchial hyper-reactivity (methacholine challenge test). Results: 27 patients were studied (age 56 +/- 9yr, height 1.67 +/- 0.08m, weight 85 +/- 14kg). Although subjects were required to demonstrate normal FEV1 at study entry, lower respiratory symptoms were uncontrolled (ACT< 20 in 25 patients; average= l 3.6 = 3.4). Following 3 months of therapy with ICS/LABA symptoms remained uncontrolled in all but 2 patients (ACT 14.1 = 4.0). Bronchial hyper-reactivity (PC20 < 4mg/dl) was noted in only 9/27patients. In contrast. FOT demonstrated abnormalities in R5, R5-20 and AX (5.30 +/- 1.93 cmH20/1/s,1.38 +/- 0.91 cmH20/I/s,10.4 +/- 9.6 cmH20/I, respectively). Abnormal FOT values were noted in a total of 17/27 patients. In addition, abnormal FOT values were noted in 9 of the 18 patients that did not demonstrate bronchial hyper-reactivity. Conclusions: Lower respiratory symptoms remained uncontrolled in the majority of patients independent of adherence to therapy. Bronchial hyper-reactivity may be responsible for symptoms in a minority of subjects. Small airway dysfunction that was not evident on spirometry persisted in the majority of subjects, providing an additional mechanism for persistence of lower respiratory symptoms. [Description provided by NIOSH]
• Subjects:
  Asthma Dust Environmental Exposure Lung Lung Diseases Men Occupational Health Respiratory Function Tests Respiratory System Respiratory Tract Diseases Risk Assessment Risk Factors Safety September 11 Terrorist Attacks Women

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• Keywords:
  Bronchial Asthma Diseases Dust Exposure Dusts Exposure Levels Humans Pulmonary System Pulmonary System Disorders Respiratory System Disorders Risk Factors Spirometry Statistical Analysis Treatment World Trade Center WTC

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• ISSN:
  1073-449X
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Abstract or Summary
• Place as Subject:
  California ; New York ; OSHA Region 2 ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  193
• NIOSHTIC Number:
  nn:20048431
• Citation:
  Am J Respir Crit Care Med 2016 May; 193(Abstract Issue):A5425
• Email:
  kenneth.berger@nyumc.org
• Federal Fiscal Year:
  2016
• Performing Organization:
  New York University School of Medicine
• Peer Reviewed:
  False
• Start Date:
  20130701
• Source Full Name:
  American Journal of Respiratory and Critical Care Medicine
• Supplement:
  Abstract Issue
• End Date:
  20170630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:3a555233497da45c339e00a4a40e2740007fad0ce280ba94eefdd4760595ad68ac3b2f6a7b98432d9524be0956ebc2b1dd6a5a20f870373584f4debcb7610309
• Download URL:
  https://stacks.cdc.gov/view/cdc/203186/cdc_203186_DS1.pdf
• File Type:
  [PDF - 17.76 KB ]