Differentiating Pyopneumothorax and Peripheral Lung Abscess: Chest Ultrasonography

doi:10.1097/00000441-200406000-00006

The American Journal of the Medical Sciences

Volume 327, Issue 6, June 2004, Pages 330-335

https://doi.org/10.1097/00000441-200406000-00006 Get rights and content

ABSTRACT

Background

Differentiation between pyopneumothorax and lung abscess can be difficult but has important therapeutic consequences. The role of chest ultrasonography in this issue remains undetermined. Sonographic features of hydropneumothorax and/or pyopneumothorax are characteristic and not difficult to recognize. In this study, the authors evaluate the usefulness of a panel of sonographic findings characteristic of hydropneumothorax in distinguishing pyopneumothorax from lung abscess.

Methods

This series included 16 patients with lung abscess and 19 with pyopneumothorax. A diagnosis of lung abscess or pyopneumothorax was based on the following criteria: pus aspiration from the lesion, appropriate clinical setting, thoracic computed tomographic findings, serial follow-up of chest radiograms, and consistent clinical course. The panel of sonographic features suggestive of hydropneumothorax, including the presence of air-fluid level, the curtain sign, loss of gliding sign above the air-fluid level, and the suspended microbubble sign, were recorded and analyzed by a consensus of blinded readers. In addition, sonographic features used to differentiate empyema and lung abscess were also evaluated.

Results

The results indicated that the presence of air-fluid level, the curtain sign, loss of gliding sign above the air-fluid level, and the suspended microbubble sign were valuable in distinguishing pyopneumothorax from lung abscess. All four sonographic findings were observed in 17 of 19 patients with pyopneumothorax. In contrast, two or fewer sonographic findings were seen in 16 patients with lung abscess. Our results confirmed that the wall characteristics, shape of the lesion, chest wall angle, and pleural separation were also useful.

Conclusions

The panel of sonographic findings is of considerable value in differentiating pyopneumothorax and lung abscess.

Section snippets

Methods

Consecutive patients who had peripheral thoracic lesions containing air-fluid level shown on chest radiograms and/or chest CT scans and who were admitted to the Taipei Veterans General Hospital were eligible for this study. Patients were excluded from this study if they had one of the followings: (1) pulmonary lesion not abutting the pleura; (2) pulmonary lesion proved to be a malignant tumor with sterile necrosis; or (3) nonempyemic hydropneumothorax. Chest ultrasonography was performed within

Results

The sonographic features evaluated in differentiating lung abscess and pyopneumothorax are summarized in Table 1. The uniformity of wall width, the smoothness of luminal margin and shape of the lesion, chest wall angle, pleural separation, the presence of air-fluid level, the curtain sign, loss of gliding sign above the air-fluid level, and the suspended microbubble sign appeared to be of significant value in differentiating lung abscess from pyopneumothorax. Nevertheless, the sharpness of

Discussion

Differentiation of lung abscess and pyopneumothorax is important because the treatment of the two diseases differs significantly. Pyopneumothorax, with or without bronchopleural fistula, usually requires tube drainage, whereas lung abscess is generally treated conservatively with appropriate antibiotics and postural drainage.

By and large, chest radiography plays a limited role in differentiating pyopneumothorax and peripheral lung abscess. Several reports have documented the ability of chest CT

Conclusion

Knowledge of the panel of sonographic findings, including the presence of air-fluid level, the curtain sign, loss of gliding sign above the air-fluid level, and the suspended microbubble sign, characteristic of hydropneumothorax and pyopneumothorax should be of value to the physicians when diagnosis of a peripheral thoracic lesion with air-fluid level is problematic. With this information, chest ultrasonography can resolve the uncertainty and substantially reduce the delay in starting effective

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ArticlesDifferentiating Pyopneumothorax and Peripheral Lung Abscess: Chest Ultrasonography

ABSTRACT

Background

Methods

Results

Conclusions

Section snippets

Methods

Results

Discussion

Conclusion

J Thorac Surg

Radiol Clin North Am

Chest

Chest

Radiologic assessment of bronchopleural fistula with empyema

Radiology

Diagnostic problems in suppurative lung disease

Arch Intern Med

Radiologic recognition of bronchopleural fistula

Radiology

Ultrasonic evaluation of radiographic opacities of the chest

AJR Am J Roentgenol

Articles
Differentiating Pyopneumothorax and Peripheral Lung Abscess: Chest Ultrasonography