The case is of a 45-year-old African American male, nonsmoker, with a history of arterial hypertension, iron deficiency anemia, and auricular fibrillation. For the past 10 years, he had multiple episodes of community-acquired pneumonia, requiring admission to the intensive care unit on several occasions. Immunodeficiency virus (HIV), cystic fibrosis, tuberculosis, and several primary immunodeficiencies had been discarded and negative family history for similar diseases. He had chronic dry cough and dyspnea with modified Medical Research Council (mMRC) scale 3/4, requiring use of domiciliary oxygen. He consulted to our institution when his respiratory symptoms increased, presenting with productive cough with purulent secretion, functional class deterioration, and dyspnea with mMRC scale 4/4. At admission, physical examination reported the following vital signs: arterial tension 130/85 mm Hg, heart rate 100 beats per minute, respiratory rates 18 breaths per minute, SO2 93%, and temperature 38  C. He showed dyspnea at rest with use of accessory muscles; wet mucous membranes, without jugular ingurgitation or neck masses; regular and rhythmic tachycardic heart sounds, without murmurs; diminished respiratory sounds in both pulmonary fields; tubal murmur in bases; unremarkable abdomen; absence of edema in extremities; and presence of digital hippocratism.
Blood work with white blood cell count 7.4 x 103/microL, neutrophils 3.17 x 103/microL, lymphocytes 2.77 x 103/microL, hemoglobin 9 g/dL, hematocrit 34%, positive C-reactive protein 16.2 mg/dL, lactate 0.7, arterial blood gases with a pH 7.38, partial pressure of carbon dioxide (PaCO2) of 76.6 mm Hg, PaO2 46 mm Hg, oxygen saturation (SaO2) 80%, and HCO3 39 mg/dL.
Chest X-ray showed a central trachea and multiple thin-walled cystic images, occupying the lower two thirds of both hemithorax, no masses, or pneumothorax (Figure 1). Thoracic CT scan showed an increased tracheal diameter, measuring 28 x 33 mm (anteroposterior x transversal) 2 cm above the aortic arch, with atonic walls and presence of cylindrical and cystic bronchiectasis (Figure 2A). Enlarged mainstem bronchus with a right mainstem bronchus (RMB) and left mainstem bronchus (LMB) diameter of 22 and 17 mm, respectively (Figure 2B-F). On 3-dimensional coronal volumetric reconstruction and multiplanar reconstruction with digital subtraction, a gradual enlargement of the trachea and diffuse dilatation of the bronchi is observed, along with cystic bronchiectasis that give a cobblestone appearance (Figure 3).
A fibrobronchoscopy was then performed revealing tracheal dilatation, with tracheal diverticula and moderate purulent secretions. Posterior to the right main bronchus giving the branches for the superior and intermediate lobe, the anatomy is altered giving rise to multiple cavitations, some of them occupied by abundant pus. Similarly, on the left main bronchus, a loss of normal structure is seen, with multiple purulent filled cavitations (Figure 4). Bronchoalveolar lavage was performed, being positive for Achromobacter xylosoxidans spp (resistant to cefepime and ceftriaxone) and Pseudomonas aeruginosa. Taking into consideration the patient's clinical, imagenological, and endoscopical findings, MKS is diagnosed.
The patient was successfully treated for this infectious episode, for which treatment with piperacillin/tazobactam was administered for 14 days. Respiratory therapy was initiated, consisting of inhalation therapy and mucus drainage using the Acapella airway clearance device. After 10 days, the patient was discharged home.
Typical out-of-hospital management includes domiciliary therapy using Venturi 50% per day, salbutamol and ipratropium bromide inhaler as needed, respiratory therapy, and inhalation of a hypertonic solution to mobilize mucous secretions. The patient has been hospitalized in approximately 17 occasions from 2015 until 2019 for pulmonary infections that have been managed efficaciously without further complications. On his last appointment with the pulmonologist, his baseline disease was stable with no further deterioration in functional class. A control chest X-ray showed an improvement in pulmonary radiolucency with decrease in air fluid levels (Figure 5).