Who Knows
Mark Crislip
Oct 26, 2021
Two consults in one workday with empyema, one with MSSA and one with MRSA and S. pyogenes. Both IVDA with no associated pneumonia, but both with trauma to the chest. Both were drained, and I was called to weigh in on how long to treat and with what.
Who knows?
I still remain amazed at the lack of evidence-based medicine to aid in deciding how to treat an empyema.
While there are numerous trials on the best mechanism for source control, there are no clinical trials on the duration of therapy and whether or not it should be IV or oral.
The British Thoracic Society says
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
Based on nothing. With similar data, the US
recommends a minimum of 2 weeks from the time of drainage and defervescence. The final duration should be determined by the sensitivities of the infecting organism, the adequacy of drainage, and the response to therapy on follow-up. If the patient has responded to therapy, there has been source control, the isolated organism is susceptible to orally bioavailable agents, and the patient is tolerating oral intake, then a transition to oral therapy can be made.
Retrospective series suggests
Length of antimicrobial therapy from time of source control was variable, with a median (interquartile range) duration of 27 (15-31) days. Of note, longer courses of parenteral, but not oral, therapy were associated with fewer cases of clinical failure.
In children, there are studies to suggest po and iv are equal:
The frequency of complications was similar with oral therapy and OPAT for children with PPE. Oral antibiotics may be considered safe and effective for children with PPE.
There are no good recommendations for how long to treat and when to change to po. It depends on the organism, adequacy of source control, and the clinical response, and is why you get to put MD/DO after your name.
My take?
This century has demonstrated that for every infection evaluated, if there is good source control, shorter duration is equal to longer, and oral is equal to iv. And Staphylococci need more aggressive therapy than Streptococci.
I can't see where the pleural space is any different except when the infection is evaluated with CT or CXR, it looks ugly for months.
In the 21st century, it seems wrong to give multiple weeks of antibiotics if there has been good source control. I suspect that once the pus has been drained, 14 days or less, probably 5-7 days of oral, is all that is needed.
But I/we so need some EBM to guide us.
Rationalization
Management of pleural infection in adults: British Thoracic Society pleural disease guideline 2010 https://thorax.bmj.com/content/65/Suppl_2/ii41
Empyema management: A cohort study evaluating antimicrobial therapy https://www.journalofinfection.com/article/S0163-4453(16)00059-1/fulltext
The American Association for Thoracic Surgery consensus guidelines for the management of empyema https://www.jtcvs.org/article/S0022-5223(17)30152-6/fulltext
Comparative Effectiveness of Oral Versus Outpatient Parenteral Antibiotic Therapy for Empyema https://pubmed.ncbi.nlm.nih.gov/26526596/