Medical Image of the Month: Cavitating Pseudomonas aeruginosa Pneumonia

Figure 1. A: Admission CXR demonstrates upper lobe bullae and left peri-hilar consolidation on background of emphysema. B: Day 4 CXR reveals more confluent consolidation and opacification of the bullous change. C: Day 8 CXR demonstrates air fluid level with increasing density of consolidation. D: Repeat CXR 6 weeks after discharge shows near complete resolution of findings with small residual cavity.

Figure 2. CT Chest with contrast confirmed extensive consolidation with cavitation and suggested possibility of atypical infection

Case Presentation

A 56-year-old woman presented with cough and shortness of breath to hospital. She had a temperature of 39.2°C and had recently completed course of steroids and antibiotics for exacerbation of chronic obstructive pulmonary disease (COPD). She was an active smoker of 15 cigarettes/day for about 40 years. No other past medical history was noted. On examination she had left-sided crepitations and oxygen saturations of 90% on room air.

Chest x-ray (CXR) (Fig 1:A) showed features of background emphysema with upper lobe peripheral bullae, larger on the left. Dense left peri-hilar consolidation was also described. SARS-CoV-2 swab was negative. White blood cells (WBC) were raised at 16.9x10⁹/L and C-reactive protein (CRP) at 331 mg/L. The rest of the blood tests were unremarkable. CURB-65 score was zero but treatment was commenced with intravenous (IV) amoxicillin & oral clarithromycin in view of level of CRP and CXR findings. On Day 4 of admission CRP spiked to 541 mg/L. Repeat CXR (Fig 1:B) showed more confluent left upper zone consolidation and increased opacification of bullous change in the left apex. Microbiologist advised switch of IV Amoxicillin to IV Co-amoxiclav. Respiratory colleagues suggested to check sputum for acid-fast bacilli (AFB). Pneumococcal & legionella urinary antigens came back negative. HIV was also excluded. Growth of Pseudomonas aeruginosa was detected on a blood-tinged sputum sample which was confirmed on 3 more subsequent samples. AFB stain was persistently negative. Blood cultures did not yield any growth.

Antibiotic therapy was escalated to IV piperacillin/tazobactam (Tazocin; Pfizer; UK) QDS (Pseudomonas dose) in light of the new finding. Inflammatory markers slowly started to shift but intermittent temperature spikes continued so repeat CXR (Fig 1:C) and subsequent computed tomography (CT) of chest with contrast (Fig 2) were obtained to assess the complex pneumonia with its striking appearances. CT confirmed extensive consolidation with cavitation and air-fluid levels in the left apical region. Patient required 2L/min supplemental oxygen at the time. By completion of 7-day course of IV piperacillin/tazobactam CRP dropped to 63 mg/L and WBC to 8.6x10⁹/L. Patient was successfully weaned off oxygen and discharged home. Repeat CXR in 6 weeks (Fig 1:D) showed marked improvement with residual small cavity.

Discussion

P. Aeruginosa - a gram negative rod is a rare cause of both CAP (community acquired pneumonia) and cavitating pneumonia. It is more commonly associated with hospital acquired pneumonia (HAP) and usually affects immunocompromised hosts (1). Cavitating pneumonia arises as a result of necrosis of lung parenchyma due to toxins derived from bacterial pathogens. Maharaj et al. (2) reviewed 9 cases of P. Aeruginosa CAP reported on PubMed from 2001 to 2016 and 5 out of 9 patients were found to be smokers. Emphysema was reported in 2 and asthma only in 1 case. The pneumonia exclusively affected upper lobes in 8 out of 9 cases. The infection was fatal in 3 cases (mean age 54) through development of septic shock. Early identification and timely treatment of P. Aeruginosa infection is crucial due to its high rate of multi-drug resistance (3). In absence of positive sputum cultures clinical suspicion based on imaging could drastically change patient’s course of illness. Presentation of upper-lobe pneumonia not responding to standard antibiotic regimens should alert clinicians to the differential of P. Aeruginosa infection. Plain radiograph usually gives sufficient information in CAP but a CT scan may be warranted on an individual basis to assess more complex pneumonia. 

Giorgi Kiladze MBcHB, MRCP(UK)

Royal Liverpool and Broadgreen University Hospitals NHS Trust

Prescot Street, Liverpool, Merseyside, UK L7 8XP

References

1. Rello J, Borgatta B, Lisboa T. Risk factors for Pseudomonas aeruginosa pneumonia in the early twenty-first century. Intensive Care Med. 2013 Dec;39(12):2204-6. [CrossRef] [PubMed]
2. Maharaj S, Isache C, Seegobin K, Chang S, Nelson G. Necrotizing Pseudomonas aeruginosa Community-Acquired Pneumonia: A Case Report and Review of the Literature. Case Rep Infect Dis. 2017;2017:1717492. [CrossRef] [PubMed]
3. Wolter DJ, Lister PD. Mechanisms of β-lactam resistance among Pseudomonas aeruginosa. Curr Pharm Des. 2013;19(2):209-22.

Abbreviations

• COPD – Chronic Obstructive Pulmonary Disease
• CXR – Chest X-ray
• WBC – White Blood Cells
• CRP – C Reactive Protein
• CURB 65 – Confusion Urea Respiratory rate Blood pressure Age 65
• IV – Intravenous
• AFB – Acid-Fast Bacilli
• HIV – Human Immunodeficiency Virus
• QDS – Quarter Die Sumendum (four times daily)
• CT – Computed Tomography
• L/min – Litres/minute
• CAP – Community Acquired Pneumonia
• HAP – Hospital Acquired Pneumonia

Cite as: Kiladze G. Medical Image of the Month: Cavitating Pseudomonas aeruginosa Pneumonia. Soulthwest J Pulm Crit Care. 2021;23(5):126-8. doi: https://doi.org/10.13175/swjpcc034-21 PDF

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: Bullous Emphysema

Figure 1. Chest radiograph showing hyperinflated lungs.

Figure 2. Panel A: Coronal view of chest computed tomography (CT) in  lung widows showing multiple large lucent spaces of lung parenchyma destruction interspersed normal lung tissue. Panel B: Axial view of chest CT showing coronal narrowing of the trachea with widening of the sagittal diameter (arrow). This is known as a saber sheath trachea which is pathognomonic of chronic obstructive pulmonary disease.

A 63-year-old gentleman, with a history of 90-pack-years of smoking and stage IV chronic obstructive pulmonary disease was receiving home oxygen at 2 L/min at baseline. He has had multiple prior hospital admissions for respiratory failure. Over the past 2 weeks he has had increased production of sputum, associated with worsening shortness of breath. He is on fluticasone-salmeterol inhaler, albuterol inhaler, and tiotropium as an outpatient.

On examination, he was hemodynamically stable, SpO2 was 92% on 4L/min of oxygen. He was in obvious respiratory distress, in a tripod position with tachypnea and using respiratory accessory muscles. Lung examination revealed diffuse expiratory wheezing.

Chest radiograph shows severe emphysema (Figure 1). Chest computed tomography showed diffuse centrilobular and bullous emphysema (Figure 2).  He was treated as an acute severe exacerbation of COPD and was eventually discharged to follow-up with the pulmonary clinic.

Emphysema is defined as alveolar destruction and airspace enlargement distal to the terminal bronchiole. There are subclassifications of emphysema based on its distribution within the secondary lobule (1). Bullae are defined as an air-filled space, greater than 1 cm in diameter, usually as a result of emphysematous destruction. Indications for bullectomy include patient symptoms, isolated bullae occupying > 30% of the hemithorax or complications arising from bullae (2).

Kai Rou Tey, MD¹; Akinbola Ajayi-Obe¹, MD; and Naser Mahmoud, MD²

¹Department of Internal Medicine, South Campus

²Department of Pulmonary, Critical Care, Allergy and Sleep

University of Arizona College of Medicine

Tucson, AZ

References

1. Terminology, Definitions, and Classification of Chronic Pulmonary Emphysema and Related Conditions: A Report of the Conclusions of a Ciba Guest Symposium. Thorax. 1959;14(4):286-299.
2. van Berkel V, Kuo E, Meyers BF. Pneumothorax, bullous disease, and emphysema. Surg Clin North Am. 2010 Oct;90(5):935-53. [CrossRef] [PubMed]

Cite as: Tey KR, Ajayi-Obe A, Mahmoud N. Medical image of the week: bullous emphysema. Souhwest J Pulm Crit Care. 2016 Apr;12(4):147-8. doi: http://dx.doi.org/10.13175/swjpcc157-15 PDF

Medical Image of the Week: Panlobular Emphysema

Figure 1. PA chest radiograph showing predominately lower lobe emphysematous changes.

A 60 year old female, non-smoker with a past medical history of chronic rhinosinusitis with nasal polyps presented with an eight year history of productive cough and dyspnea. Previous treatment with inhaled corticosteroids, courses of systemic corticosteroids and antibiotics provided modest improvement in her symptoms. Pulmonary function testing revealed a severe obstructive ventilatory defect without significant bronchodilator response and reduced diffusing capacity (DLCO). Chest x-ray surprisingly revealed lower lobe predominant emphysematous changes (Figure 1). Alpha-1-antitrypsin level was within normal range at 137 mg/dL.

Panlobular emphysema represents permanent destruction of the entire acinus distal to the respiratory bronchioles and is more likely to affect the lower lobes compared to centrilobular emphysema (1). Panlobular emphysema is associated with alpha-1-antitrypsin deficiency, intravenous drug abuse specifically with methylphenidate and methadone, Swyer-James syndrome, and obliterative bronchiolitis. Whether this pattern is seen as part of normal senescence in non-smoking individuals remains controversial (2). Panlobular emphysema may represent a phenotypically more severe disease than centrilobular emphysema and may coexist along a continuum with centrilobular emphysema (3).

Ashish Mathur MD and Tara Carr MD

Division of Pulmonary, Allergy, Critical Care and Sleep Medicine

University of Arizona College of Medicine

Tucson, Arizona

References

1. Litmanovich D, Boiselle PM, Bankier AA. CT of pulmonary emphysema-current status, challenges, and future directions. Eur Radiol. 2009;19(3): 537-51. [CrossRef] [PubMed]
2. Takahashi M, Fukuoka J, Nitta N et al. Imaging of pulmonary emphysema: a pictorial review. Int J Chron Obstruct Pulmon Dis. 2008;3(2):193-204. [PubMed]
3. Finkelstein R, Ma HD, Ghezzo H, Whittaker K, Fraser RS, Cosio MG. Morphometry of small airways in smokers and its relationship to emphysema type and hyperresponsiveness. Am J Respir Crit Care Med. 1995;152(1):267-76. [CrossRef] [PubMed]

Reference as: Mathur A, Carr T. Medical image of the week: panloubular emphysema. Southwest J Pulm Criti Care. 2015;11(2):86-7. doi: http://dx.doi.org/10.13175/swjpcc081-15 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: Aspergilloma

Figure 1.  Axial thoracic computed tomography (CT) image showing emphysematous disease throughout with prominent bullous disease in the upper lobes.  Areas of consolidation were concerning for infection.  Large cavitation with particulate matter (arrow) was seen in the left upper lobe. 

A 69-year-old woman, a current smoker, with very severe chronic obstructive pulmonary disease and prior atypical mycobacterium, was found unresponsive by her family and intubated in the field by emergency medical services for respiratory distress.  Her CT thorax showed severe emphysematous disease, apical bullous disease, and a large left upper lobe cavitation with debris (Figure 1).  She was treated with broad-spectrum antibiotics and anti-fungal medications.  Hemoptysis was never seen.  Sputum cultures over a span of two weeks repeatedly showed Aspergillus fumigatus and outside medical records confirmed the patient had a known history of stable aspergilloma not requiring therapy. 

Aspergillomas usually arises in cavitary areas of the lung damaged by previous infections.  The fungus ball is a combination of colonization by Aspergillus hyphae and cellular debris.  Individuals with aspergillomas are usually asymptomatic or have mild symptoms (chronic cough) and do not require treatment unless it begins to invade into the cavity wall.  When bleeding complications arise, surgical resection is curative but in high-risk patients, embolization may be considered as a stabilizing measure. 

Wendy Hsu, MD, Carmen Luraschi-Monjagatta, MD and Gordon Carr, MD

Division of Pulmonary and Critical Care Medicine

University of Arizona 

Tucson, AZ 

Reference 

Kousha M1, Tadi R, Soubani AO. Pulmonary aspergillosis: a clinical review. Eur Respir Rev. 2011;20(121):156-74. [CrossRef] [PubMed]

Reference as: Hsu W, Luraschi-Monjagatta C, Carr G. Medical image of the week: aspergilloma. Southwest J Pulm Crit Care. 2014;8(5):282-3. doi: http://dx.doi.org/10.13175/swjpcc044-14 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