Damian McNamara

January 24, 2017

HONOLULU — For patients with suspected methicillin-resistant Staphylococcus aureus (MRSA) sepsis who have been started on broad-spectrum antibiotics in the intensive care unit (ICU), vancomycin or daptomycin can be safely de-escalated if culture results come back negative for MRSA.

"The take-home message is to trust your culture data," said Matthew Korobey, PharmD, from Mercy Hospital St. Louis in Missouri. "At 72 hours, if your cultures are negative, with a high degree of certainty you can drop your MRSA active agent."

"It's important to know — number one — that antibiotics carry risks. As well, avoiding these agents where they may not be necessary would preserve them for use in the future," he told Medscape Medical News.

Dr Korobey presented results from a study that evaluated the timing of antibiotic de-escalation here at the Society of Critical Care Medicine 46th Critical Care Congress.

Trust your culture data.

His team randomly identified sepsis patients admitted to an ICU in a large community teaching hospital who were treated for MRSA with antibiotics from November 2011 to April 2016. For all patients, sputum and blood cultures, obtained before the first antibiotic dose, were subsequently determined to be negative for MRSA.

For 28 of the 54 patients, MRSA therapy continued beyond 48 hours; for the other 26 patients, therapy was discontinued before 48 hours.

Although the ICU mortality rate was higher in the group that had discontinued therapy at 48 hours, the difference was not significant.

Table. Outcomes by Time to Antibiotic De-escalation

Outcome Continued Beyond 48 Hours De-escalated Before 48 Hours P Value
Mean APACHE III score at baseline 52 55 .5
ICU mortality rate, % 0.0 3.6 .5
Mean time to stop or de-escalate, hours 123 24 <.0001


"It is a good study. We try to de-escalate as much as possible," said session moderator Kristine Parbuoni, PharmD, from the pediatric cardiac ICU at the Loma Linda University School of Pharmacy in California.

However, "there are patients and populations where clearly there could be more hesitancy," she told Medscape Medical News. "I work with transplant patients and with patients who are immunosuppressed. In someone who looks very ill, there can be more hesitancy to stop the antibiotics."

Dr Korobey said his team plans to act on their findings and develop an antibiotic stewardship program.

Dr Korobey and Dr Parbuoni have disclosed no relevant financial relationships.

Society of Critical Care Medicine (SCCM) 46th Critical Care Congress: Abstract 0692. Presented January 23, 2017.


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