Perfect storm: A long-term care acute hybrid hospital
Factors converge to favor drug resistance
If an evil genius wanted to design a perfect breeding ground for antibiotic resistance, he or she could scarcely come up with something more diabolical than a little-known segment of the health care system called the long-term acute care hospitals (LTACHs).
"The LTACH is like the perfect storm by way of providing an ideal setting for a convergence of risk factors leading to high levels of antibiotic resistance," said Carolyn Gould, MD, a medical epidemiologist at Emory University in Atlanta.1
"The elements going into this perfect storm include a very high rate of colonization of antibiotic-resistant organisms at the time of admission; a population — at least in our unit — of immune compromised, critically ill patients; multiple sources of infection [via] invasive devices and open wounds; antibiotic use rates comparable to ICU rates; and finally, prolonged hospitalization with the average duration of about one month."
LTACHs are relatively new entities that specialize in the care of patients who require extended hospital stays but need the intensity of services of acute care hospitals, Gould said recently in Phila-delphia at the annual conference of the Society for Healthcare Epidemiology of America.
Most LTACH patients are transferred from ICUs, and many require extended mechanical ventilation. There are about 300 LTACHs nationwide, with roughly half freestanding and the rest within hospitals, she said. After discovering a high rate of antibiotic resistance in her own unit, Gould and colleagues did a review of the literature to determine if others were having problems in these special settings. "What we found was — nothing," she said, showing a blank slide in her presentation. "We realized that this was a completely uncharted area."
To remedy the situation, the researchers assessed patient demographics, antibiotic usage data, and antibiograms for 2002 from 25 geographically diverse LTACHs. Gould and colleagues found LTACH patients had a median length of stay of 28 days. Antibiotic usage in defined daily doses/1,000 patient days for the 25 facilities was comparable to ICUs in the CDC’s National Nosocomial Infection Surveillance System (NNIS).
Rates of resistance pathogens also were comparable to ICUs, with some exceeding the 90th percentile. Methicillin-resistant Staphylococcus aureus (MRSA) was rampant, with only respondents reporting that only 16% of staph isolates were susceptible. Of interest, however, was that for most drug-bug combinations, researchers found little correlation between antibiotic usage and resistance among the LTACHs. Surveillance at the Emory LTACH revealed that 59% were infected or colonized with MRSA or vancomycin-resistant enterococci (VRE) at time of transfer to the unit, she said. Questions regarding infection control practices and the level of nosocomial transmission occurring in such units remain to be answered in a follow-up arm of the study.
"We have only information on our infection control practices, which include expanded contact isolation for VRE and contact isolation for MRSA," she told Hospital Infection Control.
"The problem with this population in general is that a lot of these LTACHs have double-occupancy rooms. One of the things we are exploring is the feasibility of universal precautions, which may be important because of the high colonization rates. But the problem with double occupancy rooms is [it would require] doing surveillance cultures on admission so you don’t end up putting a VRE patient with an MRSA patient. We did start doing surveillance cultures in our LTACH, but we are trying to get information from the other [facilities] we surveyed to find out what other people are doing," Gould added.
1. Gould CV, Steinberg JP. Antibiotic resistance (AR) in long-term acute care hospitals (LTACHs): The perfect storm? Abstract 58. Presented at the Society for Healthcare Epidemiology of America annual conference. Philadelphia; April 2004.