Ground-Glass Opacities

Reference as: Gopal V, Robbins RA. Ground-glass opacities. Southwest J Pulm Crit Care 2011;2:67-70. (Click here for PDF version)

A 54-year-old male was admitted to the medical intensive care unit complaining of abdominal pain, nausea, and vomiting for 2 days. He had a past medical history of pancreatitis in 2009, treated as outpatient, and asthma treated with albuterol inhaler as needed. His medication list included gemfibrizol, gabapentin, and amitriptyline. He drank 6-8 beers per day and smoked 1 pack-per-day for the past 40 years.

On physical examination is the patient was afebrile, his lungs are clear to auscultation, but tenderness was present in both lower quadrants. The remainder of the physical examination was normal.

Laboratory examination revealed a normal complete blood count and normal basic metabolic panel. Abnormal laboratory values included an elevated total bilirubin of 2.7 mg/dL (normal 0.2-1 mg/dL); alkaline phophatase 169 U/L (normal 10-40 U/L);  alanine aminotransferase 286 U/L (normal 10-35 U/L); amylase 468 U/L (normal 25-125 U/L), and lipase 1580 U/L (normal 8-78 U/L). Arterial blood gasmeasurements showed PaO_{2 =} 91 mm Hg, PaCO₂ = 26 mm Hg, pH = 7.52, and oxygen saturation = 98% while breathing room air.

Chest radiography (Figure 1, Panel A) was interpreted as showing a “right upper lobe infiltrate which could represent an acute pneumonia”.  No distinct abnormalities were identified on abdominal radiographs (Figure 1, Panel B).

 Figure 1. Panel A. Frontal chest radiography.  Panel B. Abdominal radiography.

To further evaluate the possibility of a right upper lobe abnormality at chest radiography, thoracic CT was performed and as showing patchy ground-glass opacities throughout the lungs bilaterally (Figure 2).

Figure 2. Representative images from thoracic CT.

Question 1. What’s the most likely diagnosis?

1. Hypersensitivity pneumonitis
2. Acute inhalational injury secondary to “huffing”.
3. Drug-induced lung disease
4. Valley Fever
5. Ground-glass opacities associated with pancreatitis

Question 2. What would you do next?

1. Hypersensitivity panel
2. Bronchoscopy with bronchoalveolar lavage
3. Begin Diflucan
4. Broaden his antibiotic coverage
5. Repeat the thoracic CT scan in 3-4 days.

The thoracic CT was repeated four days later and the ground-glass opacities seen previously had largely resolved (Figure 3).

Figure 3.  Representative images from thoracic CT performed four days following the initial study Figure 2).

These ground-glass opacities likely represent subclinical non-cardiogenic pulmonary edema in the setting of acute pancreatitis. Ground-glass opacities are foci of increased lung attenuation that do not obscure underlying vessels or bronchial margins (1). Ground-glass opacities often represent parenchymal abnormalities below the spatial resolution of high-resolution CT of the lung. Although the differential diagnosis of ground-glass opacities at high-resolution CT is large, these etiologies may be broadly divided into acute or chronic causes. Table 1 lists some of the more common causes of ground-glass opacities at high-resolution CT.

Table 1: Common Etiologies for Ground-Glass Opacity at Thoracic CT

Acute	Chronic
Pulmonary edema (cardiogenic or non-cardiogenic)	Interstitial diseases (hypersensitivity pneumonitis, desquamative interstitial pneumonia, respiratory bronchiolitis-interstitial lung disease, nonspecific interstitial pneumonia, sarcoidosis, others)
Infectious pneumonitis (PJP, CMV, HSV, RSV, others)	Bronchoalveolar carcinoma
Noninfectious pneumonitis (hypersensitivity pneumonitis, acute inhalational exposures, drug-induced lung diseases)	Other causes (drug toxicity, pulmonary alveolar proteinosis, organizing pneumonia, chroic eosinophilic pneumonia, others)

Our patient had no apparent cause, other than subclinical non-cardiogenic pulmonary edema secondary to pancreatitis. Pulmonary edema is a well known complication of pancreatitis and can be severe (2). It seems likely that, as more sensitive methods for the detection of pulmonary abnormalities, such as thoracic CT, are increasingly applied to patients with pancreatitis, that subclinical pulmonary injury may be increasingly detected.

Venu Gopal, M.D.

Chief, Infectious Disease, Phoenix VA Medical Center

Richard A. Robbins, M.D.

Chief, Pulmonary and Critical Care, Phoenix VA Medical Center

Slide Set

References

1. Miller WT Jr, Shah RM.  Isolated diffuse ground-glass opacity in thoracic CT: causes and clinical presentations.  AJR Am J Roentgenol 2005;184:613-22.
2. Raghu MG, Wig JD, Kochhar R, Gupta D, Gupta R, Yadav TD, Agarwal R, Kudari AK, Doley RP, Javed A. Lung complications in acute pancreatitis. JOP. 2007;8:177-85.

A Case of Mislabeled Identity

Reference as: Singarajah C, Park K. A case of mislabeled identity. Southwest J Pulm Crit Care 2010;1:22-27. (Click here for PDF version)

A 60-year-old man in the surgical intensive care unit for atrial fibrillation with rapid ventricular response, on his second post-operative day following colectomy, complained of worsening shortness of breath. A chest radiograph (Figure 1) was obtained. A chest radiograph performed one day previous to Figure 1 showed clear lungs, no pleural effusions, and no volume loss.

Question 1 and Figure 1: What are the abnormal findings on the chest radiograph? In particular, what technical error has occurred? 

The frontal chest radiograph shows increased opacity in the bases bilaterally, greater on the side labeled left (see “L” in the image- this is the technologist’s marker). Note the shift of the trachea towards the side labeled left. However, note also the opacity along the superior mediastinum on the right side; this opacity has the appearance of the aortic arch. Note the appearance of the stomach below the diaphragm, ipsilateral to the aortic arch. Also, the opacity at the left lung base shows a configuration resembling the heart. Taken together, these findings raise the possibility that the radiograph is mislabeled, with the “Left” marker (“L”, Figure 1) improperly placed on the patient’s right side. Prior chest radiographs not shown) confirm the patient did not have situs inversus.

There is evidence of volume loss in the right thorax (labeled incorrectly as left in this image). Note the shift of the trachea towards the side with increased lung opacity. The entire left right thorax (again, incorrectly labeled left in this image) is small, and the air column in the right mainstem bronchus abruptly terminated, suggesting endobronchial obstruction.

Furthermore, the patient had no clinical reasons for a new large pleural effusion, and recent prior films showed no pleural fluid.

Surgery was consulted and a procedure was performed. The results of this procedure are shown in Figure 2.

Question 2: What procedure was performed by the surgery team?

The surgery team improperly placed a thoracostomy tube in the left thorax because they misinterpreted Figure 1 as showing a large left pleural effusion. Figure 2 shows the tip of the thoracostomy tube in the medial superior left thorax, associated with subcutaneous emphysema. Progressive volume loss is seen on the right side, again suggesting endobronchial obstruction- note that the residual air in the right upper thorax in Figure 1 is no longer present in Figure 2. The surgery team then improperly placed a thoracostomy tube on the right side, mistaking the small, opacified right thorax for pleural effusion on that side. Figure 3 shows the new right thoracostomy tube tip located over the cranial right thorax.

The surgical team was concerned that the thoracostomy tube showed little fluid output and a second thoracotomy tube was placed on the contralateral side (Figure 3).

 

This tube also did not show significant output. The pulmonary / critical care medicine team was then consulted. The pulmonary / critical care medicine physician performed a procedure which partially corrected the cause of the patient’s original complaints. The chest radiograph following this procedure is shown in Figure 4. 

Question 3: What procedure (s) was performed by the pulmonary / critical care medicine team?

Bronchoscopy was performed, and showed significant mucous plugging. The mucous plugs were removed resulting in improved right lung aeration (Figure 4).

Learning Points:

• Physical exam would have identified improperly labeled chest radiograph
• The chest radiograph shows volume loss, suggesting endobronchial obstruction due to mucous plugging- the side of the thorax showing increased attenuation shows reduced volume. In contrast, pleural effusion would show increased opacity associated with mass effect and shift of the cardiomediastinal structures away from the side of the thorax showing increased attenuation
• Time-outs are no substitute for clinical skills.The patient had two thoracostomy tubes, both placed for incorrect reasons, one of which was placed on the wrong side all together.
• Therapy for atelectasis and mucous plugging includes the following:
  •  Patient mobilization, ambulation, sitting up;
  • Minimize anti-tussive meds (narcotics, etc), minimizes sedation;
  • Chest physiotherapy for the affected lung;
  • Continuous lateral rotation therapy for patients with altered mental status who cannot mobilize  (for example, a Triadyne bed  made by KCI or manual turning);
  • Bronchoscopy, and;
  • Mucolytics are of equivocal benefit

Clement Singarajah MD.  Associate Chief Pulmonary and Critical Care Fellowship, Phoenix VA Hospital and Good Samaritan Regional Medical Center, Phoenix AZ.

Kevin Park, MD, Pulmonary and Critical Care Medicine fellow, Phoenix VA Hospital and Good Samaritan Regional Medical Center, Phoenix AZ.

Email csingarajah@earthlink.net