Lung involvement in chronic occult aspiration :Gayathri Nair Karedath, K Praveen Kumar, V Nandini, M Krishnaprasad, E Shabana, Journal of Advanced Lung Health

CASE REPORT
Year : 2023 | Volume : 3 | Issue : 1 | Page : 30--33

Lung involvement in chronic occult aspiration

Gayathri Nair Karedath, K Praveen Kumar, V Nandini, M Krishnaprasad, E Shabana
Department of Pulmonology, Baby Memorial Hospital, Kozhikode, Kerala, India

Correspondence Address:
Dr. Gayathri Nair Karedath
Department of Pulmonary Medicine, Baby Memorial Hospital, Kozhikode, Kerala
India

Abstract

Chronic occult aspiration is the chronic aspiration of small volumes of oral and gastric contents into the lung. This is also termed as chronic microaspiration. It can lead to symptoms of gastroesophageal reflux disease and later lung involvement. This process is less familiar than the acute aspiration syndromes. Here, we present the case of an elderly male patient having diffuse esophageal spasm manifesting as recurrent chest pain and interstitial lung disease.

How to cite this article:
Karedath GN, Kumar K P, Nandini V, Krishnaprasad M, Shabana E. Lung involvement in chronic occult aspiration.J Adv Lung Health 2023;3:30-33

How to cite this URL:
Karedath GN, Kumar K P, Nandini V, Krishnaprasad M, Shabana E. Lung involvement in chronic occult aspiration. J Adv Lung Health [serial online] 2023 [cited 2023 May 28 ];3:30-33
Available from: https://www.jalh.org//text.asp?2023/3/1/30/365493

Full Text

Introduction

There is growing evidence that upper gastrointestinal (GI) dysmotility plays a significant role in the development of pulmonary pathology. This association is often overlooked. In an appropriate clinical context, chronic occult aspiration should be included in the differential diagnosis for fibrotic interstitial lung diseases (ILDs). Among patients with chronic occult aspiration, there was a high prevalence of gastroesophageal reflux disease (96%), esophageal dysfunction (40%), oropharyngeal and laryngeal dysfunction (40%), hiatal hernias (32%), obstructive sleep apnea (32%), and obesity (52%).[1] This process can lead to diseases such as recurrent bronchiolitis, persistent patchy lipoid pneumonia,[2] and pulmonary fibrosis.[3] It is suggested that chronic occult aspiration should be considered an etiology or an exacerbating factor in patients with undifferentiated ILD or differentiated ILD with an atypical course. The majority of the cases showed a predominant pattern of bronchial wall thickening,[4] centrilobular nodules, and tree-in-bud opacities, usually with lower lung zone predominance. Few cases with diffuse distribution and a few with slight upper lobe predominance were also reported. Some areas of ground-glass opacity and focal airspace opacity were also seen. Patients with greater severity or chronicity showed evidence of bronchiectasis and fibrosis. Exogenous lipoid pneumonia was the most common pathological pattern present in this group of patients. Poorly formed granulomas adjacent to or near bronchioles often associated with chronic inflammation were seen. Foreign body type multinucleated giant cell reaction was very common.

Case Report

A 79-year-old male patient presented with a history of cough, increased dyspnea, and hemoptysis of 2-day duration. He also complained of intermittent central chest pain. The patient gave a history of chronic cough with expectoration, progressive breathlessness, and chest pain for the last 15 years. He was a farmer by occupation and a reformed smoker. He was being treated as chronic obstructive pulmonary disease (COPD) with bronchiectasis. He was admitted in the hospital in 2015 and underwent a coronary artery bypass graft (CABG) based on angiographic findings. Since his chest pain persisted he was subjected to pulmonology and gastroenterology workup. Based on computed tomography (CT) scan thorax, he was diagnosed as COPD and bronchiectasis. Upper GI endoscopy revealed severe esophagitis and mucosal bulging. Mucosal biopsy was inconclusive and he was diagnosed as gastroesophageal reflux disease with severe esophagitis. He was a diabetic patient on insulin and oral hypoglycemics.

On examination, the patient was averagely built, conscious, and oriented. His vitals were normal. Vertical surgical scar of CABG was seen. On respiratory system examination, he had bilateral end-inspiratory crackles, especially in the base of the lungs.

His investigation results of 2015 were reevaluated. X-ray showed hyperinflation with reticular and cystic shadows in both lower zones [Figure 1]a. On comparison, an X-ray chest Posterioanterior view (PA) taken in 2022 showed the progression of lesions with reticular opacities in both mid and lower zones [Figure 1]b. His high-resolution computed tomography thorax and abdomen showed reticular shadows and ground-glass shadows in both lower lobes more on the right side [Figure 2]a and [Figure 2]b. It was seen that the esophagus was dilated and retention of oral contrast given was seen. His upper GI endoscopy revealed severe esophagitis.{Figure 1}{Figure 2}

A repeat CT thorax was performed which showed extensive reticular shadows, ground-glass opacities, and traction bronchiectasis involving all lobes suggestive of fibrosing lung disease [Figure 3]a. CT also showed dilated esophagus with retained food particles [Figure 3]b. Since the patient had recurrent chest pain and symptoms of acid reflux, a barium esophagogram [Figure 4]a and [Figure 4]b was advised which showed dilated esophagus with evidence of diffuse esophageal spasm (DES) (corkscrew esophagus).{Figure 3}{Figure 4}

A final diagnosis of DES, chronic occult aspiration, and interstitial fibrosis was made along with other comorbidities such as hypertension, diabetes, and coronary artery disease. Lung biopsy could not be performed considering his age and multiple comorbidities.

Discussion

This elderly man was suffering from many diseases for the last 15 years. The relationship with his upper GI symptoms and progressive lung disease was not established. Previous smoking history, coronary artery disease, hypertension, and type 2 diabetes were considered etiology. In spite of regular treatment for the above diseases, his symptoms were progressing. This prompted us to reevaluate this patient by reviewing his old investigations and doing essential investigations at this admission and tried to establish a causative relationship with his progressive lung disease with chronic aspiration due to DES.

DES is included in a broad category of esophageal dysmotility syndromes. This can be due to (1) achalasia; (2) spastic esophageal motility disorders such as DES, nutcracker esophagus, hypertensive/hypertrophic lower esophageal sphincter, nonspecific esophageal motility disorder, and presbyoesophagus; and (3) secondary esophageal motility disorders related to diabetes mellitus, alcohol consumption, collagen vascular diseases, endocrine, and neuromuscular diseases.

DES is characterized by simultaneous, repetitive high-pressure muscular contractions within the esophagus. This is associated with severe intermittent chest pain, dysphagia, and even food impaction. This can lead to chronic microaspiration. Manometrically verified DES reveals multiple nonperistaltic contractions that obliterate much of the lumen. Barium studies show rosary beads or corkscrew appearance which is diagnostic of DES. Patients with esophageal dysfunction have an inefficient passage of oral contents from the pharynx to the stomach, as well as regurgitation of previously swallowed contents. This puts them at risk for aspirating. Gastroesophageal reflux has previously been associated with ILD in a number of studies.[5],[6] It is also possible that chronic occult aspiration itself, and the recurrent inflammation that ensues, was the cause of fibrosis in these patients.

Chronic, silent microaspiration is a common but underrecognized pathologic process in pulmonary medicine. The clinical presentation is variable, and diagnosis can be challenging. Chronic aspiration of small volumes of oral and gastric contents can lead to lung disease. However, definitive proof that abnormal GER and microaspiration are a cause of ILD, promotes disease progression, or precipitates acute exacerbation of ILD is lacking.[7] Nonetheless, evidences suggest that abnormal GER and microaspiration of refluxed gastroduodenal secretions may play a significant role in the development of idiopathic pulmonary fibrosis (IPF), scleroderma, and other ILDs. The radiologic presentation was typically one of multilobar, centrilobular nodularity, tree-in-bud, and airway thickening, with a subset of patients having evidence of fibrosis. IPF is a diffuse fibrotic lung disease of unknown etiology with no effective treatment. Emerging data support a role for chronic microaspiration (i.e., subclinical aspiration of small droplets) in the pathogenesis and natural history of IPF. Defining the role of chronic microaspiration in IPF is essential as it has potential clinical, pathobiological, and treatment implications for this deadly disease. Typically, the aspiration is silent, and the patient often presents with slowly progressive symptoms of cough, shortness of breath, recurring fevers, and lung opacities on the chest radiograph.[4],[8],[9] On CT scan, the disease usually presents as diffuse basilar, centrilobular nodules, and/or tree-in-bud pattern with airway and interstitial thickening.[10],[11],[12] Often the diagnosis is not elucidated until a biopsy reveals granulomatous inflammation associated with particulate matter consistent with the oral or gastric origin, such as vegetable, lipid, or talc particles. Chronic occult aspiration has been associated with refractory asthma,[13] IPF,[14] and lung transplant rejection.[15],[16]

Conclusion

We believe that in the appropriate clinical context, chronic occult aspiration should be included in the differential diagnosis for fibrotic ILD along with diseases such as IPF, Nonspecific interstitial pneumonia (NSIP), and Hypersensitivity pneumonitis (HP). The time of diagnostic intervention during the course of the disease may in part determine the extent of fibrosis found. Chronic occult aspiration should be considered an etiology, either alone or as an exacerbating factor for chronic fibrosing ILDs.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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