Original case by Lauren Brown, MD.
Edits and graphics by Yilin Zhang, MD.
A 72 yo F with recently diagnosed metastatic renal cell carcinoma, recently diagnosed PE presents with 1 week of increasing shortness of breath and nonproductive cough. She was diagnosed with a LLL segmental and subsequental 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 “completel lung white out”.
- 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.