Diffuse aspiration bronchiolitis: analysis of 20 consecutive patients

Imaging of Aspiration: When to Suspect Based on Imaging of Bacterial Aspiration, Chemical Aspiration, and Foreign Body Aspiration

Aspiration-related syndromes comprise a broad spectrum of diseases affecting the airways and lung parenchyma resulting from inadvertent entry of oropharyngeal or gastric contents into the respiratory tract. The diagnosis can be challenging given lack of self-reported symptoms and unwitnessed or silent aspiration events. Aspiration is a common finding in healthy individuals suggesting that host defenses play a critical role in the pathophysiology. In the absence of strict criterion, a high index of suspicion is necessary based on recognition of established risk factors and identification of characteristic imaging findings. Conditions predisposing to altered levels of consciousness and neuromuscular weakness can lead to dysphagia, impaired cough reflux, and subsequent aspiration. The most salient feature on imaging is the anatomic location of the abnormalities, with the superior segments of the lower lobes and posterior segments of upper lobes involved in the recumbent position, and basilar segments of lower lobes in the upright position. Acute syndromes include pneumonia, pneumonitis, and foreign body aspiration. In the more indolent form of aspiration, bronchiectasis, diffuse bronchiolitis, and interstitial lung disease can develop. A detailed understanding of associated radiographic findings for these syndromes can help to implicate aspiration as the cause for imaging abnormalities and ultimately optimize patient management.

Persistent Fever in an Elderly Patient: Diagnostic Challenges and Management of Aspiration Pneumonitis and Organizing Pneumonia

This case report describes an 85-year-old woman with a history of aspiration pneumonia who was admitted to a rural hospital with fever, vomiting, and decreased oxygenation. Initially diagnosed with aspiration pneumonia and acute pyelonephritis, she was treated with antibiotics. Despite this, her fever persisted, and subsequent imaging suggested aspiration pneumonitis or organizing pneumonia. Her condition improved following fasting and corticosteroid therapy. This case highlights the challenges in differentiating aspiration pneumonia from aspiration pneumonitis, as both conditions may present similarly but require different treatment approaches. Persistent fever despite broad-spectrum antibiotics prompted a change in treatment strategy, leading to the introduction of corticosteroids, which improved her symptoms. This case underscores the importance of considering aspiration pneumonitis in older patients with recurrent or persistent respiratory symptoms and fever, especially when dysphagia is present and antibiotic therapy is ineffective. Early intervention with corticosteroids, particularly when imaging findings are suggestive of organizing pneumonia, can prevent further deterioration. Accurate diagnosis and timely treatment adjustments are crucial in managing aspiration-related pulmonary conditions in elderly patients.

The foregut in cystic fibrosis

The aerodigestive organs share a kindred embryologic origin that allows for a more complete explanation as to how the foregut can remain a barrier to normalcy in people with cystic fibrosis (pwCF). The structures of the aerodigestive tract include the nasopharynx, the oropharynx, the hypopharynx, the esophagus, the stomach, as well as the supraglottic, glottic, and subglottic tubular airways (including the trachea). Additional gastrointestinal (GI) luminal/alimentary organs of the foregut include the duodenum. Extraluminal foregut structures include the liver, the gall bladder, the biliary tree, and the pancreas. There are a variety of neurologic controls within these complicated anatomic compartments to separate the transit of food and liquid from air. These structures share the same origin from the primitive foregut/mesenchyme. The vagus nerve is a critical structure that unites respiratory and digestive functions. This article comments on the interconnected nature of cystic fibrosis and the GI tract. As it relates to the foregut, this has been typically treated as simple "reflux" as the cause of worsened lung function in pwCF. That terms like gastroesophageal reflux (GER), gastroesophageal reflux disease (GERD), heartburn, and regurgitation are used interchangeably to reflect pathology further complicates matters; we offer a more physiologically accurate term called "GI-related aspiration" or "GRASP." Broadly, this term reflects that aspiration of foregut contents from the duodenum through the stomach to the esophagus, into the pharynx and the respiratory tree in pwCF. As a barrier to normalcy in pwCF, GRASP is fundamentally two disease processes-GERD and gastroparesis-that likely contribute most to the deterioration of lung disease in pwCF. In the modulator era, successful GRASP management will be critical, particularly in those post-lung transplantation (LTx), only through successful management of both GERD and gastroparesis. Standardization of clinical management algorithms for GRASP in CF-related GRASP is a key clinical and research gap preventing normalcy in pwCF; what exists nearly exclusively addresses surgical evaluations or offers guidance for the management of GI symptoms alone (with unclear parameters for respiratory disease considerations). We begin first by describing the result of GRASP damage to the lung in various stages of lung disease. This is followed by a discussion of the mechanisms by which the digestive tract can injure the lungs. We summarize what we anticipate future research directions will be to reduce the impact of GRASP as a barrier to normalcy in pwCF.

A Case of Chronic Aspiration Bronchiolitis

Chronic aspiration bronchiolitis or diffuse aspiration bronchiolitis is a rare disease characterized by chronic inflammation of the bronchioles due to recurrent aspiration of foreign material. To date, there are limited data on chronic aspiration bronchiolitis because it is often present subclinically or remains undiscovered until autopsy. Additionally, time to diagnosis is often prolonged and includes invasive workup prior to definitive diagnosis. Here, we present a case of lung disease attributed to chronic aspiration after a thorough workup resulted in histopathology consistent with a primary diagnosis of aspiration bronchiolitis. Radiographic and pathologic specimens also demonstrated features of usual interstitial pneumonia adding to the complexity of pathology that can be seen with aspiration diseases.

A case of diffuse aspiration bronchiolitis due to oesophageal stenosis after radiation therapy

A 66-year-old woman was hospitalized for recurrent pneumonia twice in 1 year. After treatment for pneumonia, chronic coughing, sputum and low-grade fever continued, so she was referred and admitted to our hospital for investigation. Chest computed tomography revealed a lung infiltrative shadow and diffuse centrilobular micronodules. Histological findings from transbronchial lung biopsy showed chronic inflammation and giant cells in the bronchiole. These findings were compatible with diffuse aspiration bronchiolitis (DAB), which is characterized by chronic inflammation of the bronchioles caused by recurrent aspiration of foreign bodies. Oesophagogastroduodenoscopy revealed stenosis of the oesophageal entrance, which was thought to be caused by radiation therapy for hypopharyngeal cancer 20 years before. Antibiotic treatment ameliorated the centrilobular nodule shadow. After discharge, there was no recurrence. This is the first case report of DAB resulting from oesophageal stenosis associated with hypopharyngeal cancer and will serve as an educational case.

Hemorrhaging from an Intramedullary Cavernous Malformation Diagnosed Due to Recurrent Pneumonia and Diffuse Aspiration Bronchiolitis

While aspiration pneumonia constitutes the majority of pneumonia cases in the elderly, it remains highly underdiagnosed. We experienced a case of recurrent pneumonia and chronic cough that was later diagnosed as aspiration pneumonia and diffuse aspiration bronchiolitis (DAB) due to recurrent hemorrhaging from an intramedullary cavernous malformation. The patient was finally diagnosed when life-threatening respiratory depression caused emergency attention. This is the first report of hemorrhaging from an intramedullary cavernous malformation diagnosed due to aspiration pneumonia and DAB. These findings highlight the importance of considering aspiration in cases with recurrent pneumonia or chronic cough. The underlying cause may be a life-threatening condition.

Overview and Challenges of Bronchiolar Disorders

Bronchiolar abnormalities are common and can occur in conditions that affect either the large airways or the more distal parenchyma. In this review, we focus on the diagnosis and management of primary bronchiolar disorders, or conditions in which bronchiolitis is the predominant pathologic process, including constrictive bronchiolitis, follicular bronchiolitis, acute bronchiolitis, respiratory bronchiolitis, and diffuse panbronchiolitis. Due to the nature of abnormalities in the small airway, clinical and physiological changes in bronchiolitis can be subtle, making diagnosis challenging. Primary bronchiolar disorders frequently present with progressive dyspnea and cough that can be out of proportion to imaging and physiologic studies. Pulmonary function tests may be normal, impaired in an obstructive, restrictive, or mixed pattern, or have an isolated decrease in diffusion capacity. High-resolution computed tomography scan is an important diagnostic tool that may demonstrate one or more of the following three patterns: 1) solid centrilobular nodules, often with linear branching opacities (i.e., "tree-in-bud" pattern); 2) ill-defined ground glass centrilobular nodules; and 3) mosaic attenuation on inspiratory images that is accentuated on expiratory images, consistent with geographic air trapping. Bronchiolitis is often missed on standard transbronchial lung biopsies, as the areas of small airway involvement can be patchy. Fortunately, many patients can be diagnosed with a combination of clinical suspicion, inspiratory and expiratory high-resolution computed tomography scans, and pulmonary function testing. Joint consultation of clinicians with both radiologists and pathologists (in cases where histopathology is pursued) is critical to appropriately assess the clinical-radiographic-pathologic context in each individual patient.

Reflux-Aspiration in Chronic Lung Disease

Microaspiration, or silent aspiration, is commonly suspected in patients with refractory respiratory symptoms, including unexplained chronic cough, asthma, chronic obstructive pulmonary disease, bronchiolitis, bronchiectasis, and idiopathic pulmonary fibrosis. This suspicion is driven by the high prevalence of gastroesophageal reflux in these otherwise disparate disorders. Frequently, patients receive aggressive treatment for gastroesophageal reflux disease as a means of treating their underlying respiratory conditions, even in the absence of overt symptoms of reflux. However, clinical trials have not demonstrated a clear impact on outcomes with this strategy, and in some instances there may be potential for harm. Mechanistic studies have increasingly used gastric biomarkers obtained directly from the airways to confirm the association between reflux and respiratory disease, but results are limited by methodologic flaws and correlation. The best evidence of aspiration directly causing respiratory disorders is the histopathologic detection of foreign bodies. For most of the other chronic respiratory disorders, microaspiration may be uncommon or a secondary aggravating factor, as in patients with acute exacerbations of chronic obstructive pulmonary disease or idiopathic pulmonary fibrosis. In some cases, microaspiration is probably not a significant factor at all, such as in unexplained chronic cough. It is important to distinguish between conditions in which aspiration is primarily or directly causal and conditions in which aspiration may be indirectly aggravating, to help identify whether interventions targeting reflux and aspiration precautions should be recommended to patients. Our clinical review examines some of the evidence supporting reflux-aspiration as a mechanism for several chronic respiratory disorders and offers some management considerations when reflux-aspiration is suspected.

Recent advances in the understanding of bronchiolitis in adults

Bronchiolitis is injury to the bronchioles (small airways with a diameter of 2 mm or less) resulting in inflammation and/or fibrosis. Bronchioles can be involved in pathologic processes that involve predominantly the lung parenchyma or large airways, but, in some diseases, bronchioles are the main site of injury ("primary bronchiolitis"). Acute bronchiolitis caused by viruses is responsible for most cases of bronchiolitis in infants and children. In adults, however, there is a wide spectrum of bronchiolar disorders and most are chronic. Many forms of bronchiolitis have been described in the literature, and the terminology in this regard remains confusing. In clinical practice, a classification scheme based on the underlying histopathologic pattern (correlates with presenting radiologic abnormalities) facilitates the recognition of bronchiolitis and the search for the inciting cause of the lung injury. Respiratory bronchiolitis is the most common form of bronchiolitis in adults and is usually related to cigarette smoking. Currently, the diagnosis of respiratory bronchiolitis is generally achieved based on the clinical context (smoking history) and chest CT findings. Constrictive (obliterative) bronchiolitis is associated with airflow obstruction and is seen in various clinical contexts including environmental/occupational inhalation exposures, transplant recipients (bronchiolitis obliterans syndrome), and many others. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is increasingly recognized and can be associated with progressive airflow obstruction related to constrictive bronchiolitis ("DIPNECH syndrome"). Diffuse aspiration bronchiolitis is a form of aspiration-related lung disease that is often unsuspected and confused for interstitial lung disease. Novel forms of bronchiolitis have been described, including lymphocytic bronchiolitis and alveolar ductitis with emphysema recently described in employees at a manufacturing facility for industrial machines. Bronchiolitis is also a component of vaping-related lung injury encountered in the recent outbreak.

Imaging In Acute Bronchiolitis: Evaluation of The Current Practice In a Kuwaiti Governmental Hospital and Its Possible Impact on Hospitalization Period

BACKGROUND AND OBJECTIVES

Guidelines for acute bronchiolitis recommend primarily supportive care, but unnecessary treatment measures remain well documented. This study was designed to assess the Al-Adan Hospital pediatricians` attitude towards imaging of inpatients with bronchiolitis aiming to evaluate its utilization and possible impact on patients` management and length of hospital stay.

SUBJECTS AND METHODS

This study included 194 cases of acute bronchiolitis admitted to Al-Adan Hospital. Number of X-Rays done following admission and reasons stated in the files were recorded. Bronchiolitis severity was estimated from the data obtained.

RESULTS

Chest X-Rays were ordered in 52.1% of our inpatients with acute bronchiolitis. In nearly half of those cases, the reason for X-Ray request is a clinical severity factor, namely desaturations and apneas, and in rest of the cases, no specific reason for ordering X-Rays was documented. Significantly more patients who had two or more X-Rays were prescribed antibiotics and had statistically longer hospital stay. The number of X-Rays performed during admission was not a significant contributor to the need for PICU care, however, it was a significant factor affecting the length of hospital stay.

CONCLUSION

The implementation of acute bronchiolitis guidelines regarding imaging in admitted cases with acute bronchiolitis is highly recommended in Al-Adan hospital. Clear documentation for the reasons behind ordering X-Rays is needed for those cases. A decrease in the X-Ray utilization and subsequent unnecessary antibiotic use can help in decreasing the costs and hazards of hospitalization for patients with acute bronchiolitis.

Perspectives in veterinary medicine: Description and classification of bronchiolar disorders in cats

This Perspectives in Veterinary Medicine article seeks to define, describe putative causes, and discuss key diagnostic tests for primary and secondary bronchiolar disorders to propose a classification scheme in cats with support from a literature review and case examples. The small airways (bronchioles with inner diameters <2 mm), located at the transitional zone between larger conducting airways and the pulmonary acinus, have been overlooked as major contributors to clinical syndromes of respiratory disease in cats. Because the trigger for many bronchiolar disorders is environmental and humans live in a shared environment with similar susceptibility, understanding these diseases in pet cats has relevance to One Health. Thoracic radiography, the major imaging modality used in the diagnostic evaluation of respiratory disease in cats, has low utility in detection of bronchiolar disease. Computed tomography (CT) with paired inspiratory and expiratory scans can detect pathology centered on small airways. In humans, treatment of bronchiolar disorders is not well established because of heterogeneous presentations and often late definitive diagnosis. A review of the human and veterinary medical literature will serve as the basis for a proposed classification scheme in cats. A case series of cats with CT or histopathologic evidence of bronchiolar lesions or both, either as a primary disorder or secondary to extension from large airway disease or interstitial lung disease, will be presented. Future multi‐institutional and multidisciplinary discussions among clinicians, radiologists, and pathologists will help refine and develop this classification scheme to promote early and specific recognition and optimize treatment.

Pathology of Chronic Hypersensitivity Pneumonitis What Is It? What Are the Diagnostic Criteria? Why Do We Care?

Context.—

Chronic hypersensitivity pneumonitis (CHP) has emerged from obscurity during the past 15 years and is now recognized as a very common form of fibrosing interstitial pneumonia but one that is frequently misdiagnosed both clinically and on surgical lung biopsy as usual interstitial pneumonia/idiopathic pulmonary fibrosis (UIP/IPF) or fibrotic nonspecific interstitial pneumonia.

Objective.—

To review the pathologic features of CHP.

Data Sources.—

Clinical, pathology, and radiology literature were used.

Conclusions.—

Upper lobe–predominant fibrosis and/or air-trapping on computed tomography scan are features of CHP but not UIP/IPF; however, radiologic separation is possible in only about 50% of cases. Morphologically, CHP sometimes mimics UIP/IPF, but CHP often shows isolated foci of peribronchiolar (centrilobular) fibrosis, frequently associated with fibroblast foci, and in CHP, fibrosis may bridge from the centrilobular region to another bronchiole, an interlobular septum, or the pleura (“bridging fibrosis”). This set of findings is uncommon in UIP/IPF. In addition, CHP may produce a picture of fibrotic nonspecific interstitial pneumonia. Although giant cells/granulomas are usually present in subacute hypersensitivity pneumonitis, they are much less frequently found in CHP, and their absence does not contradict the diagnosis. This diagnostic separation is clinically important because CHP is treated differently than UIP/IPF is (immunosuppressive agents versus antifibrotic agents); further, there are some data to suggest that removing the patient from antigen exposure improves outcome, and there is evidence that patients with CHP have a much better survival prognosis after lung transplantation than do patients with UIP/IPF. In most cases, accurate diagnosis of CHP requires consultation among clinicians, radiologists, and pathologists.

Correlation between the severity of critically ill patients and clinical predictors of bronchial aspiration

Objective:

To determine whether the severity of non-neurological critically ill patients correlates with clinical predictors of bronchial aspiration.

Methods:

We evaluated adults undergoing prolonged orotracheal intubation (> 48 h) and bedside swallowing assessment within the first 48 h after extubation. We collected data regarding the risk of bronchial aspiration performed by a speech-language pathologist, whereas data regarding the functional level of swallowing were collected with the American Speech-Language-Hearing Association National Outcome Measurement System (ASHA NOMS) scale and those regarding health status were collected with the Sequential Organ Failure Assessment (SOFA).

Results:

The study sample comprised 150 patients. For statistical analyses, the patients were grouped by ASHA NOMS score: ASHA1 (levels 1 and 2), ASHA2 (levels 3 to 5); and ASHA3 (levels 6 and 7). In comparison with the other patients, those in the ASHA3 group were significantly younger, remained intubated for fewer days, and less severe overall clinical health status (SOFA score). The clinical predictors of bronchial aspiration that best characterized the groups were abnormal cervical auscultation findings and cough after swallowing. None of the patients in the ASHA 3 group presented with either of those signs.

Conclusions:

Critically ill patients 55 years of age or older who undergo prolonged orotracheal intubation (≥ 6 days), have a SOFA score ≥ 5, have a Glasgow Coma Scale score ≤ 14, and present with abnormal cervical auscultation findings or cough after swallowing should be prioritized for a full speech pathology assessment.