An elderly male presents following a syncopal event ...

An elderly male with a history of metastatic non-small cell lung cancer, CAD s/p CABG and ischemic cardiomyopathy s/p an AICD is brought in by EMS following a fall down some stairs.  He reports feeling very lightheaded as he was going up the stairs and then falling backwards before blacking out.

His vital signs on ED arrival are T 36.7˚C P 138 R 25 BP 106/56SpO2 95% on 4L NC.  An ECG demonstrates sinus tachycardia.  A CXR is obtained and the results are shown below.

Noting the pleural effusion on Chest X-ray, you decide to take a look with the ultrasound and this is what you see:

What's your differential diagnosis?  What would your next steps in management be?

Scroll down for the Case Conclusion.

Final Diagnosis:  Empyema with Tamponade Physiology

Case Conclusion:  As stated above, the patient had a trauma workup which was negative for any injury following a fall down the stairs.  The ultrasound shows a complex, septated effusion consistent with an exudative effusion (see below).  A CT of the chest with contrast was performed demonstrating a large effusion with tamponade physiology.

A chest tube was placed with drainage of 1500 ml of purulent fluid with overall improvement in vital signs and the patient was started on antibiotics.  The fluid grew Group C Beta Streptococci. 

Learning Points:  The medical workup of the geriatric fall patient is often much more complex than evaluating for traumatic injury alone.  After taking a more extensive history, the “fall down stairs” may actually be “syncope” or “lightheadedness”, significantly broadening the differential to cardiac, metabolic, neurologic and infectious etiologies. 

Similarly to “syncope” in the elderly, the finding of a pleural effusion itself has a broad differential [1].  

Source:  Hooper, C., Lee, Y. G., & Maskell, N. (2010). Investigation of a unilateral pleural effusion in adults: British Thoracic Society pleural disease guideline 2010. Thorax, 65(Suppl 2), ii4-ii17.

In a patient with cancer, history of heart failure, hypotension and tachycardia, many of the above are plausible etiologies.

Both in terms of sensitivity and specificity, bedside ultrasound is superior to supine chest X-ray in diagnosing pleural effusions [2,3].  Beyond diagnosing the presence of a pleural effusion, bedside ultrasound can also aid in determining the underlying etiology.  Using their sonographic features, pleural effusions can be categorized into anechoic, complex non-septated, complex septated and homogenously echogenic [2].

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A prospective analysis of 320 patients carried out from 1985 to 1989 assessed whether the sonographic appearance of an effusion could predict the nature of the pleural effusion [4]. They found that while simple anechoic effusions could be transudative or exudative, a complex or echogenic effusion was always exudative.  Septa are essentially fibrin strands that tend to form in effusions that are rich in protein, and therefore are seen in all kinds of exudates including empyema, hemothorax, parapneumonic effusions and malignant effusions.  

The presence of pleural septations may have bearing on success of chest tube drainage.  While a small retrospective study of 36 patients with parapneumonic effusions found no correlation between the presence of septations and need for subsequent intervention following chest tube placement, a larger prospective study of 163 patients found that the presence of septations on initial ultrasound was associated with an increased need for subsequent intracellular fibrinolytic therapy (OR 2.79, P=0.001) and surgical intervention  (OR 3.92, P=0.004) [5,6]. 

Case Conclusion by Maia Dorsett (@maiadorsett)

References:

1.  Hooper, C., Lee, Y. G., & Maskell, N. (2010). Investigation of a unilateral pleural effusion in adults: British Thoracic Society pleural disease guideline 2010. Thorax, 65(Suppl 2), ii4-ii17.
2. Tobin, C. L., Porcel, J. M., Wrightson, J. M., Waterer, G. W., Light, R. W., & Lee, Y. G. (2012). Diagnosis of pleural infection: state-of-the-art. Current Respiratory Care Reports, 1(2), 101-110.
3. Soni, N. J., Franco, R., Velez, M. I., Schnobrich, D., Dancel, R., Restrepo, M. I., & Mayo, P. H. (2015). Ultrasound in the diagnosis and management of pleural effusions. Journal of hospital medicine, 10(12), 811-816.
4. Yang, P. C., Luh, K. T., Chang, D. B., Wu, H. D., Yu, C. J., & Kuo, S. H. (1992). Value of sonography in determining the nature of pleural effusion: analysis of 320 cases. AJR. American journal of roentgenology, 159(1), 29-33.
5. Kearney, S. E., Davies, C. W. H., Davies, R. J. O., & Gleeson, F. V. (2000). Computed tomography and ultrasound in parapneumonic effusions and empyema. Clinical radiology, 55(7), 542-547.
6. Chen, K. Y., Liaw, Y. S., Wang, H. C., Luh, K. T., & Yang, P. C. (2000). Sonographic septation: a useful prognostic indicator of acute thoracic empyema. Journal of ultrasound in medicine, 19(12), 837-843.