Medical Image of the Week: Saber Sheath Trachea

Figure 1. A: Narrowing in the mid and lower parts of the trachea on the scout film (arrow). B: Cross sectional image from chest computed tomography (CT) showing coronal narrowing of the trachea (arrow).  C: Cross sectional images from chest computed tomography (CT) showing sagittal widening of the trachea (arrow).  No mass or external compression seen.

Figure 2. Bronchoscopy image that shows the coronal narrowing and sagittal widening of the (A) proximal trachea, (b) mid trachea and (C) distal trachea.

A 79-year-old man with chronic obstructive pulmonary disease (COPD) and an active smoker was transferred for evaluation of tracheal narrowing and concerns of malignant external compression versus tracheobronchomalacia for possible stenting.

The patient underwent both chest computed tomography (Figure 1) and bronchoscopy (Figure 2) that confirmed the diagnosis of saber-sheath trachea and ruled out external compression. The airway was still adequately patent during inspiration and expiration with no clear dynamic collapse.

Saber-sheath trachea is commonly described as intra-thoracic coronal narrowing and sagittal widening of the trachea (like a sword sheath). Repetitive cartilaginous injury from excessive coughing and elevated intra-thoracic pressure causes degeneration and calcification of the trachea cartilage, leading to remodeling and bending of the tracheal cartilage (1). Presence of saber-sheath trachea is highly associated with obstructive lung disease, which is present in our patient (2). There is no known specific treatment for saber-sheath trachea, however if patient with saber-sheath trachea were to require intubation, air leak can be a concern due to the rigid deformity of the trachea (3).

See-Wei Low, MD¹; Huthayfa Ateeli, MD²; James Knepler, MD²

¹ Department of Internal Medicine and ² Pulmonary, Allergy, Critical Care and Sleep Medicine

Banner University Medical Center Tucson

Tucson, AZ, USA

References

1. Ismail SA, Mehta AC. "Saber-sheath" trachea. J Bronchol Intervent Pulmonol 2003;10:296-7. [CrossRef]
2. Greene R. Saber-sheath trachea: relation to chronic obstructive pulmonary disease. AJR Am J Roentgenol. 1978;130:441-5. [CrossRef] [PubMed]
3. Wallace E, Chung F. General anesthesia in a patient with an enlarged saber-sheath trachea. Anesthesiology. 1998;88:527-9. [CrossRef] [PubMed] 

Cite as: Low S-W, Ateeli H, Knepler J. Medical image of the week: saber sheath trachea. Southwest J Pulm Crit Care. 2017;14(6):283-4. doi: https://doi.org/10.13175/swjpcc056-17 PDF 

Medical Image of the Week: Infected Emphysematous Bulla

Figure 1. Portable AP chest X-ray revealing dense opacity within the lingula of left lung.

Figure 2. Thoracic CT with contrast showing lobar consolidation with increased lucency compatible with emphysema.

Figure 3. (A) Chest CT one year prior demonstrating severe emphysema. (B) Chest CT on admission showing new fluid-filled bulla (red arrow) in the setting pneumococcal pneumonia.

A 65 year-old man with chronic obstructive lung disease (COPD), hypertension and alcohol abuse presented to the emergency department with complaints of feeling unwell and shortness of breath. He was tachycardic but otherwise hemodynamically stable, afebrile, and requiring 3 liters/min supplemental oxygen. Pertinent initial laboratory findings revealed a neutrophilic predominant leukocytosis (WBC 37.8 x 10³ micro/L) with lactic acidosis (2.7 mMol/L). Chest radiograph showed a dense opacity within the region of the lingula (Figure 1). Follow-up CT chest confirmed a consolidation likely representing lobar pneumonia in the setting of severe bullous emphysema (Figure 2). A large fluid-containing emphysematous bulla (Figure 3) was present which was not visualized one year prior. 

He was started on broad spectrum antibiotics after peripheral blood cultures were drawn which revealed Streptococcus pneumoniae. Broad spectrum antibiotics were discontinued and patient was started on intravenous ceftriaxone 2g every 24 hours. He improved clinically and was discharged home after 4 days.

Pneumococcal pneumonia remains the most common cause of community-acquired pneumonia and accounts for nearly 66% of all bacteremic pneumonias (1,2). Our patient had multiple risk factors for developing pneumococcal pneumonia including alcohol abuse, COPD, and history of cigarette smoking. Pneumococcal pneumonia often causes dense consolidation within the lung in a well-defined lobar or segmental distribution. In emphysema areas of lucency may be seen within the consolidation which may mimic other processes such as necrosis. The pathogenesis of fluid accumulation in an emphysematous bulla is not well understood but can be associated with severe lung infection (3). Percutaneous drainage is not recommended and bronchoscopy is not usually required unless there is another indication (3). Antibiotic therapy in those who are asymptomatic has not shown to add any benefit in resolution or preventing infection (3).

Norman Beatty MD¹, Kyle McKeown MPH², Kelly M. Hager MPH², and Stephen J. Scholand MD³

¹ Department of Medicine, Banner-University Medical Center South, Tucson, AZ USA

² University of Arizona College of Medicine, Tucson, AZ USA

³ Division of Infectious Diseases, Department of Medicine, MidState Medical Center, Meriden, CT USA

References

1. Torres A, Peetermans WE, Viegi G, Blasi F. Risk factors for community-acquired pneumonia in adults in Europe: a literature review. Thorax. 2013 Nov;68(11):1057-65. [CrossRef] [PubMed]
2. Fine MJ, Smith MA, Carson CA, Mutha SS, Sankey SS, Weissfeld LA, Kapoor WN. Prognosis and outcomes of patients with community-acquired pneumonia. A meta-analysis. JAMA. 1996 Jan 10;275(2):134-41. [CrossRef] [PubMed]
3. Chandra D, Rose SR, Carter RB, Musher DM, Hamill RJ. Fluid-containing emphysematous bullae: a spectrum of illness. Eur Respir J. 2008 Aug;32(2):303-6. [CrossRef] [PubMed]

Cite as: Beatty N, McKeown K, Hager KM, Scholand SJ. Medical image of the week: infected emphysematous bulla. Southwest J Pulm Crit Care. 2016;14(1):37-8. doi: https://doi.org/10.13175/swjpcc006-17 PDF 

Medical Image of the Week: Severe Atelectasis with Tracheal Shift

 

Figure 1. Panel A: Initial chest x-ray shows left lower lobe collapse due to mucus plugging and atelectasis with a significant shift of the trachea to the left (arrow). Panel B: Follow up chest x-ray shows marked improvement in aeration of the left lung and return of the trachea to midline (arrow).

A 59-year-old woman with severe oxygen dependent COPD presented with acute respiratory distress requiring intubation and was found to have left lower lobe collapse with tracheal shift. Her past medical history consists of severe malnutrition, alcohol abuse, and emphysema with recurrent pneumonias associated with acute respiratory failure often requiring intubation. She has greater than a 50-pack year history of tobacco use. She has undergone bronchoscopy and multiple CT Chest imaging without evidence of an endobronchial lesion or malignancy. Postural drainage and percussion along with antibiotics and inhaled bronchodilators resulted in marked improvement in the left lower lobe.

Ishna Poojary MD, Janet Campion MD

University of Arizona Medical Center

Tucson, AZ

Reference as: Poojary I, Campion J. Medical image of the week: severe atelectasis with tracheal shift. Southwest J Pulm Crit Care. 2014;9(3):160. doi: http://dx.doi.org/10.13175/swjpcc115-14 PDF

Medical Image of the Week: Bilateral Pneumothorax, Pneumomediastinum, and Massive Subcutaneous Emphysema

Figure 1.  Computed tomography of the thorax showing subcutaneous air dispersed in the adipose tissue, separating the fascia of the pectoralis major, and the delineation of its fibers (top arrow), pneumothorax compressing the lung (middle arrow), and pneumomediastinum compressing the trachea (bottom arrow).

An 80 year old man with chronic obstructive pulmonary disease (COPD) presented to the emergency department with respiratory distress and poor oxygen saturation. Physical exam revealed an obese male in respiratory distress with poor air entry bilaterally and scattered wheezing. His chest, neck, tongue, and lips were swollen. The patient was intubated for respiratory failure, felt to be due to angioedema. His oxygen saturation immediately improved, however the patient developed progressive swelling throughout his body including his eyelids, fingers and toes. Diffuse crepitus was felt on palpation. Chest radiography and computed tomography (CT) of the chest revealed large bilateral pneumothoraces, pneumomediastinum, and subcutaneous emphysema (Figure 1). Bilateral chest tubes were inserted with re-expansion of both lungs. Over the next several days his respiratory parameters improved, with full re-expansion of the lungs and reabsorption of the pneumomediastinum and subcutaneous emphysema. The patient was extubated successfully and was discharged in good health.

Bilateral spontaneous pneumothorax, pneumomediastinum, and subcutaneous emphysema (SCE) are complications that may occur individually or rarely concomitantly, as in our case, during COPD exacerbations (the exact occurrence rate has not been described in the literature) (1-3). Bilateral spontaneous pneumthorax occurs in 1.9% of all spontaneous pneumothorax (4). The diagnosis is made with physical exam and appropriate imaging. Depending on the tension physiology, these conditions may lead to rapid respiratory failure and decreased cardiac output, especially when complicated by pulmonary barotrauma during mechanical ventilation (5,6).  In severe cases, SCE may involve respiratory compromise by compressing the trachea.

The early diagnosis with meticulous physical exam and relevant testing is essential, in order to immediately initiate appropriate management, and hence avoid the life-threatening complications associated with spontaneous pneumothorax, pneumomediastinum, and subcutaneous emphysema.

Zavier Ahmed MD, Manpreet Singh MD, Ricardo Lopez, MD

Icahn School of Medicine at Mount Sinai

Queens Hospital Center

82-68 164th Street

Queens, NY

References

1. Williams-Johnson J, Williams EW, Hart N, Maycock C, Bullock K, Ramphal P. Simultaneous spontaneous bilateral pneumothoraces in an asthmatic. West Indian Med J. 2008;57(5):508-10.[PubMed] 
2. Karakaya Z, Demir S, Sagay SS, Karakaya O, Ozdinc S. Bilateral spontaneous pneumothorax, pneumomediastinum, and subcutaneous emphysema: rare and fatal complications of asthma. Case Rep Emerg Med. 2012; 242579. [PubMed] 
3. Limthongkul S, Wongthim S, Udompanich V, Charoenlap P, Nuchprayoon C. Spontaneous pneumothorax in chronic obstructive pulmonary disease. J Med Assoc Thai. 1992;75(4):204-12. [PubMed] 
4. Athanassiadi K, Kalavrouziotis G, Loutsidis A, Hatzimichalis A, Bellenis I, Exarchos N. Treatment of spontaneous pneumothorax: ten-year experience. World J Surg, 1998;22: 803–6. [CrossRef] [PubMed] 
5. Hashim T, Chaudry AH, Ahmad K, Imhoff J, Khouzam R. Pneumomediastinum from a severe asthma attack. JAAPA. 2013;26(7):29-32. [CrossRef] [PubMed] 
6. Sakamoto A, Kogou Y, Matsumoto N, Nakazato M. Massive subcutaneous emphysema and pneumomediastinum following endotracheal intubation. Intern Med. 2013;52(15):1759. [CrossRef] [PubMed]

Reference as: Ahmed Z, Singh M, Lopez R. Medical image of the week: bilateral pneumothorax, pneumomediastinum, and massive subcutaneous emphysema. Southwest J Pulm Crit Care. 2014;8(3):181-2. doi: http://dx.doi.org/10.13175/swjpcc020-14 PDF

Medical Image of the Week: Pneumomediastinum

Figure 1.  Chest x-ray (CXR) shows subtle evidence of pneumomediastinum with air outlining left cardiac border and trachea (arrows).

 

Figure 2. Chest computerized tomography (CT) showing pneumomediastinum (Panel A) extending into lower neck (Panel B) without evidence of pneumothorax.

A 65 year old man presented with mild increase in shortness of breath. He had a past medical history of diabetes mellitus, hypertension, and severe malnutrition with percutaneous endoscopic gastrostomy (PEG) placement after a colectomy and end ileostomy for sigmoid volvulus. CXR (Figure 1) suggested a pneumomediastinum with subsequent chest CT (Figure 2) confirming moderate sized pneumomediastinum. He had a chronic cough from chronic obstructive pulmonary disease (COPD) as well as aspiration and chest CT also demonstrated emphysema with small blebs. He denied any significant chest pain. He was followed conservatively with imaging and discharged in stable condition.

Pneumomediastinum can be caused by trauma, esophageal rupture after vomiting (Boerhaave’s syndrome) and can be a spontaneous event if no obvious precipitating cause is identified (1). Valsalva maneuvers such as cough, sneeze, vomiting and childbirth, can all cause pneumomediastinum. Risk factors include asthma, COPD, interstitial lung disease and inhalational recreational drug use. Hamman's sign (a crunching sound in time with the heartbeat) can occasionally be heard.  More commonly, subcutaneous emphysema is felt on exam (crepitus). Complications can include single or bilateral pneumothorax, tension pneumothorax and pleural effusion. CXR often does not identify mediastinal air and CT imaging is highly sensitive and confirmatory. Conservative management is recommended with close clinical follow up for possible complications.

Rene Franco, Jr MD, Mohammad Dalabih MD, Janet Campion MD

University of Arizona Medical Center, Tucson AZ

Reference

1. Newcomb AE, Clarke CP. Spontaneous Pneumomediastinum. Chest. 2005;128:3298-3302. [CrossRef] [PubMed] 

Reference as: Franco R Jr, Dalabih M, Campion J. Medical image of the week: pneumomediastinum. Southwest J Pulm Crit Care. 2014:8(1):46-7. doi: http://dx.doi.org/10.13175/swjpcc160-13 PDF