SESSION TITLE: Pulmonary Vascular Disease Student/Resident Case Report Posters I
SESSION TYPE: Medical Student/Resident Case Report
PRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PM
INTRODUCTION: Constrictive bronchiolitis is a small airway fibrotic respiratory disease that surrounds the lumen of the bronchioles with fibrotic concentric narrowing and obliteration. It is limited to the bronchioles and does not extend into the alveoli. Visscher and Myers noted that Constrictive Bronchiolitis is often patchy and focal, making the diagnosis difficulty from a transbronchial biopsy. Unfortunately it is unresponsive to corticosteroid therapy and has a poor prognosis. Environmental and occupational causes of Constrictive Bronchiolitis will continue to be discovered.
CASE PRESENTATION: A 64 y.o male presented with progressive shortness of breath that worsened rapidly in the end of the summer of 2013, Pulmonary Function Test showed mild restrictive and constrictive pattern with low DLCO that decreased significantly and disproportionate to FEV1 and FVC changes in the same period, and he required increasing Oxygen requirement. Right Heart Catheterization revealed moderate pulmonary hypertension with normal PCWP. The patient is known to have obstructive sleep apnea. Other investigations include V/Q scan and connective tissue diseases work up are negative. Chest HRCT showed no significant findings. In view of poor response to pulmonary hypertension treatment with Tadalafil, Irbesartan, and Ambrisentan. Therefore, open lung biopsy was done which showed Constrictive Bronchiolitis. The patient is a former smoker, quit more than 16 years ago, and had silica exposure in the past. He lives in rural area, and has significant exposure to wood burning fumes.
DISCUSSION: Constrictive Bronchiolitis is uncommon in nontransplant patients. There has been reports that connect Constrictive Bronchiolitis to multiple fumes, silica, oral toxins, multiple diseases including connective tissue diseases, and previous lung infections. Our patient has significant and continuous exposure to wood burning fumes, which worsen his symptoms, especially in the summer time when he gets more exposure to camp fire smoke. Even though he had exposure to silica in the past, we don’t think silica is the cause of it because imaging studies do not reveal any changes consistent with silicosis and because of the remote exposure history. His Pulmonary Hypertension is most likely the consequence of severe hypoxemia secondary to the combination of Constrictive Bronchiolitis and Obstructive Sleep Apnea. OSA alone usually causes mild pulmonary hypertension and does not explain the significant pulmonary hypertension of the patient.
CONCLUSIONS: Constrictive Bronchiolitis can be caused by exposure to wood burning fumes, and the continuous exposure will worsen the disease and cause severe hypoxemia leading to pulmonary hypertension.
Reference #1: Daniel W. Visscher and Jeffrey L. Myers "Bronchiolitis", Proceedings of the American Thoracic Society, Vol. 3, No. 1 (2006), pp. 41-47.
Reference #2: Gary R Epler "Diagnosis and treatment of constrictive bronchiolitis". F1000 Medicine Reports 2010, 2:32 (doi:10.3410/M2-32)
DISCLOSURE: The following authors have nothing to disclose: Mohammad Taleb, Imad Hariri, Abdulmonam Ali, Vasuki Anandan, Youngsook Yoon
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