Abstract
Air-fluid levels within emphysematous lung bullae are a relatively uncommon occurrence in patients with preexisting bullous disease, and are not commonly reported. We report 2 cases of new onset air-fluid levels in patients with underlying bullous disease with substantially different clinical presentations but with clinical improvement after medical therapy only.
Introduction
Bullous lung disease can be congenital or acquired, and is most commonly associated with COPD, but has also been reported with cocaine use, sarcoidosis, Marfan and Ehlers-Danlos syndromes, and cadmium exposure.1–5 The finding of fluid-containing emphysematous bullae is an underreported complication of bullous lung disease and is thought to be a separate clinical entity from lung abscess. The etiology of intrabullous fluid is not completely understood and the optimal management remains controversial.6 Some authors have reported spontaneous resolution of this entity,7,8 while others have reported improvement after medical therapy alone,9,10 or in combination with more invasive therapies.6,11–18 In this paper we describe the clinical course, management, and outcomes of 2 cases of fluid-containing emphysematous bullae managed at our institution.
Case Report 1
In December 2009, a 59-year-old human immunodeficiency virus (HIV) positive man, on highly active anti-retroviral therapy (HAART, emtricitabine/tenofovir and lopinavir/ritonavir), with last CD4 of 635 cells/μL (normal range 323–1,546 cells/μL) and viral load of 388 copies/mL (normal range < 48 copies/mL), lifelong tobacco abstinence, and history of emphysema/asthma, with preexisting bullous disease status post right and left sided bullectomy in 2008 and 2002, respectively, presented with 5 days of left-sided, pleuritic chest pain, productive cough with yellowish sputum, shortness of breath, and 1 day of scant hemoptysis. There was no report of fever, poor dentition, unconsciousness, or previous similar episodes. His plain film of the chest revealed emphysematous changes with multiple left-sided air-fluid levels, without substantial surrounding infiltrates (Fig. 1). A plain film from 1 month earlier is displayed for comparison (Fig. 2). The chest computed tomogram (CT) revealed extensive emphysematous changes with 2 well defined air-fluid levels (Fig. 3). The patient was admitted and started empirically on intravenous piperacillin-tazobactam. Laboratory tests showed a normal complete blood count, chemistries, and liver function tests. His infectious workup, including sputum Gram-stain and culture, 3 sputum for acid-fast bacillus stain, blood cultures, fungal cultures, and fungal serologies were all negative. Alpha-1 antitrypsin levels were within normal limits. The patient displayed clinical improvement and was discharged on day 5 of hospitalization, with oral moxifloxacin to complete a 6-week course. Chest CT performed 2 weeks and 6 months after discharged showed complete resolution of the air-fluid levels within the bullae.
Posterior-anterior and lateral view chest x-ray shows an oval anterior and medial opacity, with 2 well defined air-fluid levels in the left lung (arrows).
Posterior-anterior view chest x-ray obtained 1 month before demonstrates emphysematous changes but no air-fluid level or consolidation.
Helical computed tomogram of the chest, axial and sagittal images, confirm the presence of extensive emphysematous changes with bullous formation, some of which exhibit air-fluid content.
Case Report 2
In August 2009, a 56-year-old incarcerated man with a medical history notable for COPD, with known bullae, hyperlipidemia, active tobacco use, and peptic ulcer disease, was admitted to the intensive care unit after presenting with 3 days of progressive shortness of breath, right anterolateral, sharp chest pain, productive cough with scant hemoptysis, fevers, and chills. His vitals signs on admission were: temperature 36.5°C, blood pressure 75/52 mm Hg, respiratory rate 28 breaths/min, heart rate 154 beats/min, and oxygen saturation ∼90% on a Venturi face mask, with FIO2 of ∼0.60. Physical exam was remarkable for moderate respiratory distress with tachypnea and use of accessory respiratory muscles, decreased breath sounds, and egophony in the right lung field. His initial chest x-ray showed air-space disease in the right lung and a right-lower-lobe bulla with an air-fluid level (Fig. 4). Previous chest x-ray is displayed for comparison purposes (Fig. 5). CT of the chest 3 days after admission revealed severe pneumonia involving the right lung, with extensive fluid collections filling the pre-existing large pulmonary bullae (Fig. 6). His labs were significant for leukocytosis (white-blood-cell count, 11.9 × 103 cells/μL [normal range 3.6–11.0 × 103 cells/μL]) and acute renal failure, with a creatinine level of 2.0 mg/dL (normal range 0.7–1.6 mg/dL), and a blood urea nitrogen level of 55 mg/dL (normal range 7–25 mg/dL). The patient was monitored closely, did not require endotracheal intubation, and was placed initially on moxifloxacin and linezolid. Microbiologic studies came back positive for methicillin-sensitive Staphylococcus aureus in the sputum; otherwise, blood cultures, HIV test, sputum acid-fast bacillus × 3, urine Legionella antigen, respiratory syncytial virus, and influenza washes were negative. He was then switched to intravenous oxacillin, and later to oral cephalexin. The patient gradually recovered, with interval improvement of his renal failure and pneumonia. He was discharged after 3 weeks of hospitalization, and completed 6 weeks of antibiotic therapy. A chest CT done 9 months after discharge showed complete resolution of previously described air-fluid levels within the bullae.
Chest x-ray anterior-posterior view shows a large area of consolidation in the right lung, with a central air-fluid level (arrow).
Previous chest x-ray 2 months before in the same patient demonstrates pulmonary emphysema, with no consolidation or fluid collections.
Chest computed tomogram, axial images with mediastinal and lung window, show extensive pulmonary emphysema with multiple air-fluid levels.
Discussion
Air-fluid levels within bullae represent a unique pathologic presentation and can encompass a wide clinical spectrum. It complicates the course of preexisting bullous emphysematous disease and is considered to be a separate entity from a lung abscess.19 The etiology is not completely understood, but is thought to be due to inadequate bronchial communication, leading to insufficient drainage of sterile fluid from the bullae. Consequently, fluid accumulates, resulting in inflammation and infection.15,20–22 Also, adjacent infection causing sterile inflammation in the bulla, primary infection, and, although rare, hemorrhage into the bulla might be other possible etiologic mechanisms. The diagnosis relies on radiographic evidence of previous bullous disease and the posterior development of the classic air-fluid level.23 Additional clinical and radiological features, such as a sharp inner margin of the cavity wall, minimal involvement of the lung surrounding the cavity, fairly rapid changes in the quantity of intrabullous fluid by chest x-ray, without expectoration of putrid sputum, and clinically mild illness have been considered supportive of the diagnosis.2 From previously reported cases, this entity is often an asymptomatic or minimally symptomatic condition with an indolent course. However, some reports have documented the presence of important complications such as underlying malignancy,19 tuberculosis, congestive heart failure,16 hemorrhage secondary to barotrauma,24 or a more symptomatic course with adjacent infiltrates.19,21
Our cases illustrate opposing extremes of the spectrum of this disease, but with clinical improvement in both cases after medical therapy only. Wherein the first case manifests mild symptoms, absence of a systemic inflammatory response, negative cultures, and a short hospital stay, the second case represents a more aggressive presentation consistent with severe sepsis, positive microbiologic studies, and a long hospital stay. Some of this variability may be attributed to the presence of risk factors in the host and/or the virulence of the offending bacteria. One can speculate that the presence of treated HIV, tobacco abstinence, and negative or low microbiologic burden could have allayed a more complicated course in the first patient, while, on the other hand, the history of institutionalization, tobacco use, and the presence of Staphylococcus aureus might have worsened the severity of disease in the second. Previous case reports have described the possible association of lung parenchyma infiltrates and symptoms;9 however, our first case was symptomatic with a benign course, despite the absence of an infiltrate. Interestingly enough, the presence of an infiltrate has been related to a favorable outcome.25
Notably, in both cases, despite the substantial variability of the initial clinical presentation, the antimicrobial therapy up to 6 weeks alone, without an invasive procedure such as percutaneous drainage, chest tube placement, or surgical resection, was successful. However, in mild cases such as our first case, you could argue for treating with a simpler antibiotic regimen (eg, amoxicillin-clavulanate) or treating with expectant management only. At follow-up these 2 patients did not have recurrence of symptoms or radiologic findings of air-fluid levels. Moreover, the majority of previously reported cases with this condition have not needed surgical interventions for improvement.14 Some authors reported symptomatic relief and pulmonary function improvement after percutaneous drainage; however, without a control group, and a reported operative mortality of 7%.17 Therefore, we underscore the favorable outcome without the need for invasive procedures, regardless of the initial clinical presentation and presence or absence of risk factors. Thus, when selecting a therapeutic modality for this entity, we favor initial medical therapy or expectant management, depending on the severity, symptoms, and presence of risk factors. We recommend considering more invasive procedures only in those cases with an unfavorable response or persistent symptoms.
Footnotes
- Correspondence: Andres F Henao-Martinez MD, Division of Infectious Diseases, University of Colorado School of Medicine, 12700 E 19th Avenue, Aurora CO 80045. E-mail: andres.henaomartinez{at}ucdenver.edu.
The views expressed in this article are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs, the University of Colorado Denver, or the University of Texas Health Science Center at San Antonio.
Dr Adams has disclosed relationships with the Chest Foundation, the National Institute of Health, the Veterans Affairs Cooperative Studies Program, Bayer, Boehringer Ingelheim, Centocor, GlaxoSmithKline, Novartis, Pfizer, and Schering-Plough.
The other authors have disclosed no conflicts of interest.
- Copyright © 2012 by Daedalus Enterprises Inc.
