A new application for a monitoring technique allows doctors to better predict antibiotic concentrations in the blood of critically ill patients, according to a study by Nyack Hospital researchers. The technique involves a combination of blood level monitoring and computerized decision support.

The findings will be presented at the European Congress of Clinical Microbiology and Infectious Diseases, held in Barcelona, Spain from May 10-13, 2014 by Andras Farkas, PharmD, Clinical Pharmacy Manager at Nyack Hospital. The study was conducted in collaboration with the Infectious Disease section and the University of Queensland in Brisbane, Australia.

The researchers studied levels of meropenem (Merrem), an antibiotic often used to treat critically ill patients for common diseases such as pneumonia and abdominal infections. It is an increasingly important antibiotic in light of increasing bacterial resistance, Dr. Farkas notes.

"Unlike many other antibiotics used at our hospital, it is not common practice to monitor concentrations of this medication in patients' blood," said Dr. Farkas. "Having accurate blood levels established is very important for most antibiotics, since those levels are often linked to the efficacy of the medication at treating the infection, or to safety parameters, such as causing an unwanted reaction. Our study is the first to support the utility of this approach combined with a computerized decision support algorithm for meropenem."

The drug is administered intravenously. According to Dr. Azfar Chak, Infectious Disease Physician at Nyack Hospital, doctors generally decide the dose based on clinical judgment or anecdotal evidence. The usual dose is 1 gram every 8 hours. Occasionally, for serious infections, doctors administer 2 grams every 8 hours. "To our surprise, several of these patients - especially at younger age - required even more than the 2g every 8 hours dose of this antibiotic to maintain adequate levels," Dr. Chak said. "This study is very important, because it provides objective evidence of actual meropenem concentrations from the blood of nearly 40 critically ill patients. Once these levels are measured, we can then use the computerized algorithm to establish the optimal regimen of meropenem for the treatment of a specific diseases and organism in this diverse population of patients."

As a result of their findings, Drs. Farkas and Chak suggest that doctors take into consideration the monitoring of meropenem blood concentrations for select critically ill patients, including those at younger age or the ones infected by more resistant organisms. They note that currently only a few U.S. hospital laboratories have the means to run such assays for meropenem.