Empyema: Clinical sciences

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Introduction0:00–1:22

Empyema is a collection of purulent fluid within the pleural cavity but outside of the lung. This occurs when there is inoculation of bacteria or other microorganisms within the pleural space leading to the development of frank pus.
Pneumonia is the most common cause of empyema, but it can result from blunt or penetrating chest trauma, esophageal rupture, hematogenous seeding of infection, or mediastinitis.
Empyema goes through three stages: exudative, fibrinopurulent, and organizing. In the exudative stage, fluid accumulates in the pleural space.
Next, in the fibrinopurulent stage, invasion of bacteria activates the immune response that leads to septations. After a few weeks, the organizing stage occurs.
In this stage, there is a formation of a thick connective tissue on both pleural surfaces that prevents the lung from fully expanding.
This is known as pleural rind or peel. Empyema can quickly progress to a systemic infection so it should be diagnosed and treated promptly.When a patient presents with a chief concern suggesting empyema, your first step is to perform an ABCDE assessment to determine whether the patient is unstable or stable.

Acute management1:22–2:00

If the patient is unstable, stabilize the airway, breathing, and circulation. Consider intubation for patients with signs of impending acute respiratory failure.
Then, obtain IV access and initiate IV fluids for resuscitation, while continuously monitoring vital signs like pulse oximetry, blood pressure, and heart rate.Once you have initiated the acute management, your next step is to obtain a focused physical examination and order labs including CBC, CMP, CRP, and albumin.

Unstable patient2:00–4:55

On history, patients typically report symptoms of severe infection, such as fever, chills, malaise, loss of appetite, and weight loss.
Be sure to ask about any symptoms they had prior, since empyema takes time to develop. They might report respiratory symptoms in the previous weeks or even months like cough, pleuritic chest pain, and dyspnea.
In severe cases, physical exam might reveal altered mental status, hypotension, tachycardia, and tachypnea, which are signs of systemic infection.
On examination of the chest, you can expect to find dullness on percussion, decreased breath sounds, and decreased fremitus.
Labs will likely show leukocytosis, hyponatremia, elevated CRP, and low albumin. If your patient presents with these findings, suspect empyema with a systemic infection or sepsis.
These patients need to be dealt with promptly because the disease can rapidly progress. Now, let's discuss the work-up.
The diagnostic tests you need to order are a chest x-ray and pleural ultrasound. On chest x-ray, you will likely see pleural thickening, blunting of the costophrenic angle, and a loculated effusion.
Now, here’s a catch! Your average chest x-ray with posteroanterior view might not help you distinguish a loculated effusion from some other pathology.
You’ll have to obtain a lateral decubitus x-ray. If the fluid stays in place and doesn’t flow down to the gravity-dependent position, it is a loculated effusion.
On pleural ultrasound, you can expect to see a loculated pocket of fluid with or without septations, or hyperechoic debris as well as pleural thickening.
These radiologic findings help you confirm your diagnosis of empyema with systemic infection or sepsis.Alright, now that you have made the diagnosis, let’s talk about management.
Your first step is to start empiric IV antibiotics. Then, place a large bore chest tube sometimes under ultrasound guidance to locate the loculation and drain the empyema.
Finally, make sure to continue treating the underlying infection or sepsis that might be present.Now that we’ve treated the unstable patients, let's switch gears and talk about the stable patients.

Stable patient4:55–6:18

Your first step in evaluating a stable patient is to obtain a focused history and physical, as well as labs such as CBC, CMP, CRP, and albumin.
Stable patients often report symptoms of infection like fever, malaise, loss of appetite, and weight loss; in addition to respiratory symptoms like cough, pleuritic chest pain, and dyspnea.
Sometimes patients might have had pneumonia recently, or are currently suffering from one. This is a very important clue to determine in which stage the empyema is, which will help you treat it.
History might also reveal one or more risk factors including a history of aspiration, poor dental hygiene, alcohol or substance use disorder, and immunosuppression.On physical exam, you can expect to find dullness on percussion, decreased breath sounds, and decreased fremitus of the chest.
Finally, labs might reveal leukocytosis, hyponatremia, elevated CRP, and a low albumin. If your patient presents with these findings, you should suspect empyema.
Next, you need to confirm your suspicions with some imaging, including chest x-ray, pleural ultrasound, and CT of the chest.

Imaging6:18–7:32

On chest x-ray, you will likely see pleural thickening, blunting of the costophrenic angle, and sometimes loculated effusions within the pleural cavity, which might have air in it.
Again, be sure to obtain a lateral decubitus x-ray which will help you distinguish loculated effusions from other pathologies.
As for the pleural ultrasound, it might show a loculated pocket of fluid with or without septations or hyperechoic debris, as well as pleural thickening.
Lastly, on a chest CT, you can expect full visualization of the loculations with pleural thickening and enhancement along the walls of the fluid collection.
Any of these radiographic findings should heighten your suspicion of an empyema.Here’s a clinical pearl! Fluid can collect in the fissures of the lung and be confused with a lung abscess.
Make sure not to confuse the two, as they are managed differently!Alright, to confirm your diagnosis, you need to obtain a diagnostic thoracentesis with collection of the pleural fluid.

Diagnostic Thoracentesis7:32–8:18

This pleural fluid should be sent for analysis along with gram stain and culture. The thoracentesis should yield frank purulent fluid consistent with empyema.
In terms of pleural fluid analysis, you will look at three main points including a pH level less than 7.2, LDH greater than 1000 IU/L, and glucose less than 40 mg/dL.
A positive gram stain and cultures will tell you which microbe might be responsible for the infection. This confirms your diagnosis of empyema for your patient.Alright, now that we have confirmed the diagnosis of empyema, let's turn our attention to management.

Management8:18–8:58

Your first step is to start your patient on IV antibiotics. If pleural fluid cultures results have not come back yet, consider IV antibiotics that cover the most common pathogens such as Streptococcus pneumoniae, oral streptococci and anaerobes, and Staphylococcus aureus.
Then, continue with an image-guided placement of a chest tube to drain the purulent or infected pleural fluid, which is the best choice of treatment for empyema in the exudative stage that hasn’t formed septations yet.Once you have placed the chest tube, assess the patient’s response in 24 to 72 hours.

Adequate Response8:58–9:47

Repeat a chest CT to visualize the status of the empyema after drainage. If there is an adequate response, you will see that the size of the empyema has decreased, which means it’s resolving.
Then, you can switch to PO antibiotics according to the culture for a full course. Continue to monitor the chest tube output, and consider removing the tube once the output becomes clear, and the drainage has significantly reduced, understanding that physiologic pleural drainage can be up to 300 mL per day.
Remember to treat the underlying etiology and follow up closely on an outpatient basis.On the flip side, if the repeated CT reveals that the empyema is still present, getting larger, or developed loculations, your patient has an inadequate response to the treatment.

Inadequate Response9:47–11:09

In this case, you need to repeat drainage of the purulent fluid and change the antibiotics according to the cultures. You might also be dealing with an empyema in the fibrinopurulent stage, so consider administering tPA/DNase to break up the loculations as an additive therapy.
At this point, you need to consult the surgical team for more invasive measures of treatment. Usually Video-Assisted Thoracoscopic Surgery, or VATS, with decortication is indicated to treat the empyema.
Finally, remember to treat the underlying etiology.Here’s another clinical pearl! If empyema has been present for more than 3 weeks, there’s often a fibrinous pleural rind that forms.
Now, even if the fluid is drained, the rind remains and prevents the lung from fully expanding. If you do any imaging at this stage, it’ll look like pneumothorax.
With the rind present, the fluid will just refill the cavity and the entire process goes in circles. Surgery is essential to remove the rind and allow the lung to expand.Okay, let’s briefly go back to the diagnostic thoracentesis to discuss alternative diagnoses that could mimic an empyema.

Findings Not Consistent With Empyema11:09–11:40

If the pleural fluid analysis as well as the gram stain and culture are not consistent with empyema, you should consider alternative diagnoses that could cause pleural effusion.
These include malignancy like lung cancer or mesothelioma, lung abscess, or even heart failure. Alright, as a quick recap… Empyema is a collection of pus within the pleural cavity.

Review11:40–12:50

Unstable patients should be evaluated with a chest x-ray and pleural ultrasound. Treatment includes IV empiric antibiotics, chest tube for drainage, and treating the underlying infection or sepsis.
When it comes to stable patients, they’re assessed using a chest x-ray, ultrasound, and a chest CT to visualize the empyema.
Then, perform diagnostic thoracentesis for pleural fluid analysis to confirm your diagnosis. Treatment includes IV antibiotics and chest tube drainage, with reassessment within 24 to 72 hours for response to therapy.
If the empyema is resolving, switch to PO antibiotics, pull the chest tube when output decreases and becomes clear, and follow-up with the patient on an outpatient basis.
However, if the empyema persists or enlarges, repeat drainage, change antibiotics, and consult the surgical team for