Original case by Lauren Brown, MD.
Edits, updates and graphics by Yilin Zhang, MD.
- List causes of a “total lung white out” or opacified hemithorax
- Recognize how a CXR may help you differentiate between these causes
- Identify the most common causes of bloody pleural effusions
- Differentiate between a bloody pleural effusion and hemothorax
This is a relatively short case focused around a clinical image that takes ~ 10 – 15 min. The clinical image version of this case can be found here, which will take ~ 5 min.
A 72 yo F with metastatic renal cell carcinoma presents with 1 week of increasing shortness of breath and nonproductive cough. One week ago, she was diagnosed with a LLL segmental and subsegmental PE and was started on therapeutic enoxaparin. Within days of starting anticoagulation, she reports worsening shortness of breath. She otherwise denies any fevers, chills, hemoptysis.
She has renal cell carcinoma metastatic to the liver and lymph nodes for which she is taking nivolumab. On exam is she afebrile, tachycardic to 110s, RR 22, 96% on RA. She has absent breath sounds in the R hemithorax.
What is your differential for an opacified L hemithorax?
She underwent a thoracentesis with removal 1.5L of bloody fluid. How can you differentiate a bloody pleural efffusion from a hemothorax?
Get a pleural hematocrit. When the pleural hematocrit/ blood hematocrit is > 0.5, then it is a hemothorax1,2. This patient’s pleural hematocrit was only 5% (serum hematocrit 26%) which argues against a hemothorax.
What else causes a bloody pleural effusion?
In one study3 (which looked at 715 patients with pleural effusion, though only 59 were bloody pleural effusions), almost 50% of bloody pleural effusions were from malignancy. Other causes include post-traumatic (12%), parapneumonic (10%). Other uncommon causes include TB, aortic dissection, pancreatic diseases, trapped lung and asbestosis.
Our patient subseuqently also underwent a CT scan, which showed the following:
How might a CT scan help differentiate between a hemothorax and a simple pleural effusion?
TAKE HOME POINTS:
- Look at the deviation of the trachea to narrow the diagnosis of an opacified hemithorax (aka “total lung white out”.
- The most common causes of bloody pleural effusions are malignant effusions, post-traumatic and parapneumonic effusions.
- A pleural hematocrit can help distinguish between a hemothorax and bloody pleural effusion
- Porcel, JM & Light, RW. Diagnostic Approach to Pleural Effusion in Adults. Am Fam Physician. 2006; 73(7):1211-1220.
- Stark, P. Imaging of Pleural Effusions in Adults. Finley, G & Lee, SI (eds.) In UpToDate, Inc. Maltham, WA. Accessed on November 22, 2017.
- Villena, V, et al. Clinical Implications of Appearance of Pleural Fluid at Thoracentesis. CHEST 2004; 125: 156–159.