Case Presentation by Dr. Adnan Sabic
CC: Shortness of breath
HPI: 52 year old male presents to the ED with four weeks of SOB and right sided chest pain. His symptoms have gradually progressed in severity and were worse with exertion. These symptoms started several days after he fell against a counter and struck his right chest wall. He initially had a “small gash and black and blue mark” on his right lateral chest wall but these resolved over the course of the month. He denied similar symptoms in the past. He denied any nausea or vomiting. He denied any orthopnea or PND symptoms. He did not take any medication for this. He complained of low grade fever. Review of systems is otherwise negative.
PMH: HTN, uncontrolled.
PFH: Negative for DM, HTN, Ca.
PSH: positive for tobacco use, negative for EtOH or illicit drugs.
Vital signs: 37.9 C, 111, 26, 160/95 and 98 % RA,
General: WNWD 52 year old male who appears to be tachypneic.
Eyes: PERRLA, EOMI
Neck: trachea is midline, no c-spine tenderness, no crepitus
Cardiovascular: S1 &S2, tachycardic, no murmors, no JVD
Respiratory: Tachypnic, clear breath sounds on the left, but absent breath sounds on the right chest in all lung segments.
GI: soft, NT/ND, +BS
MSK: chest wall was non-tender throughout palpation without any crepitance. Rest of the exam is unremarkable.
Neurological: A&O X3, no obvious neurological deficits.
CXR was obtained:
A) What is your suspected diagnosis?
- Empyema/Intraparenchymal lung abscess
- Unilateral diaphragm perforation
B) A chest tube was placed and 1500 cc of yellow, exudative fluid was removed from the right chest cavity. Which of the following are consistent with exudative fluid?
- The ratio of pleural fluid protein to serum protein is greater than 0.5
- The ratio of pleural fluid LDH and serum LDH is greater than 0.6
- The difference between the albumin level in the blood and the pleural fluid is greater than 1.2 g/dL
- All of the above
C) What is the most common cause of this condition?
- Penetrating trauma
- Esophageal rupture
- Pleural extension of pneumonia
- Previous thoracic surgery
- Previous chest tube placement
An empyema is a collection of exudate in the pleural cavity. It is most often caused by pleural extension of pneumonia, but it may be also caused by any seeding of the pleural cavity from penetrating trauma, esophageal rupture, previous thoracic surgery or previous chest tube placement. Empyema is also an under recognized complication of blunt thoracic trauma and may be an occult perpetrator in subsequent respiratory failure and need for mechanical ventilation.
In the emergency setting, chest radiography is indicated to differentiate other chest pathology that can present similarly. A CT of the chest may be necessary to assess for underlying pneumonia, lung abscess, tumor, septations or other pleural disease. When 2-view chest radiographs are used to detect pleural fluid, the sensitivity is 67% and the specificity is 70%. Decubitus views increase the degree of confidence. However, decubitus views are often skipped, and the patient instead undergoes a CT examination.
In the absence of trauma or surgery, the diagnosis of empyema would be very unlikely. Clinically, one might suspect empyema if the patient has fever, productive cough, or clinical symptoms consistent with pneumonia. Radiographically and without a known history, it would be difficult to differentiate the two entities. The gold standard for differentiating them is tube thoracostomy and evaluation of the fluid.
The fluid obtained by tube thoracostomy is either exudate or transudate. Transudate is produced through pressure filtration without capillary injury while exudate is due to leakage from inflammatory cells. It is critical to identify the fluid as either exudate or transudate in order to make an accurate diagnosis. Light’s criteria, which compares chemistries of the fluid to blood is used to classify the fluid. Fluid is likely exudative if one of the following is true: the ratio of pleural fluid protein to serum protein is greater than 0.5, the ratio of pleural fluid LDH to serum LDH is greater than 0.6, the difference between albumin the fluid and albumin in the blood is less than 1.2 g/dL. Usually protein content of exudate is greater than 35 g/L and cholesterol content is greater than 45 mg/dL.
The definitive management of empyema should be made in consultation with thoracic surgery and infectious disease. The gold standard of treatment has been prompt tube thoracostomy and intravenous antibiotics, but recent literature has suggested a benefit in both intrapleural fibrinolytics and early VATS. Pleural fluid should be sent for analysis and they should be admitted to the hospital for continued therapy.