Infectious Disease Compendium



Infection of the pleural space; make the diagnosis on the basis of the parameters of the tap of the pleural fluid. Lots of PMN's, bacteria on gram stain, pH < 7.2 (if in the 6 range think esophageal rupture), glucose level < 40 mg/dl, and lactic dehydrogenase > 1000 IU/liter. From 2007 review: PubMed.

Plural Fluid

Uncomplicated Complicated Empyema
Appearance slightly turbid cloudy pus
Ph >7.3 <7.2 na
Glucose >60 <40 na
Glucose ratio pleural/serum >0.5 <0.5 na
LDH <700 >1000 na
PMN count <15,000 >25,000 na
Culture negative occ positive usually positive

These often occur on a spectrum, and the closer it is to pus, the more loculation, the more you should push to drainage.

Epidemiologic Risks

Pneumonia, esophageal rupture, trauma.


Anything (PubMed).

- Community-acquired infections: 50% are Streptococci (especially the milleri group) and 20% have anaerobes.

Viral is due to Bornholm disease aka epidemic pleurodynia aka epidemic myalgia aka the devils grippe,due to Coxsackie B virus and other viruses

- Hospital-acquired: methicillin-resistant Staphylococcus aureus, 25%; Enterobacteriaceae, 18%; Pseudomonas spp. 5%, Enterococcus 12%.

Mortality: hospital-acquired infection 47% vrs community 17% and gram-negative 45%, S. aureus 44%, or mixed aerobic infections 46%, vrs streptococcal infection 17% and anaerobes bacteria 20%.

If you find Candida, think esophageal perforation.

Most common form of extra-pulmonary tuberculosis. The adenosine deaminase is useful in making the diagnosis (PubMed).

Empiric Therapy

Depends on what you suspect and the gram stain.

Usually a (third generation cephalosporins PLUS metronidazole) OR (quinolone PLUS metronidazole OR clindamycin) OR carbapenems alone OR penicillin/beta-lactamase inhibitors alone.

Duration of therapy is longer rather than shorter; it is until the patient is cured. What a concept.

"The duration of treatment for pleural infection has not been assessed in detailed clinical trials, however antibiotics are often continued for at least 3 weeks, again based on clinical, biochemical (eg, CRP) and radiological response (PubMed)."

There are no good recommendations for how long to treat and when to change to po. It depends in the organism, adequacy of source control, and the clinical response and is why you get to put MD/DO after you name.


Drain it. Sooner rather than later. Never let the sun set on an empyema unless, of course, you live at the poles. Video Assisted Thoracic Surgery (VATS) has a better outcome than regular chest tubes for large complex empyemas.

Culture positive empyema's do worse clinically by most parameters (PubMed).


In the middle ages they did not take prisoners on the battlefield. There was someone whose job it was to slit the throats of the enemy wounded (barbers became surgeons, these folks became agents). That is the role of antibiotics in empyema: You win or lose based on the drainage.

Curious Cases

Relevant links to my Medscape blog

Answer these questions three

One Darn Thing After Another

NSAIDs. Not necessarily for what ales you.


Horse, Zebra or Unicorn?

Fatherly Advice

The Girl With Empyema

Multiples of Seven

Last Update: 06/25/18.