ICAAC 2006: Physicians warn of overuse of vancomycin in treating hospital-acquired pneumonia
Vancomycin may be overused for the treatment of hospital-acquired pneumonia, perhaps because of physicians' perceptions that patients are at high risk for methicillin-resistant Staphylococcus aureus (MRSA), according to a study by Robert H. Eng, MD, and colleagues at the Veterans Affairs New Jersey Health Care System in East Orange, NJ. The study was presented at the 45th ICAAC meeting in Washington, DC.
The researchers sought to determine whether vancomycin was used appropriately or inappropriately for the treatment of pneumonia at their institution, in accordance with guidelines developed by the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS). To do so, they developed an electronic form at the point of antibiotic order to capture vancomycin prescribers' decisions and thoughts.
The point-of-care electronic form was administered to all vancomycin prescribers from October to December 2004 and captured the following information: body site of infection, reason for vancomycin use, and culture results. Individual cases were then reviewed using electronic medical records that included pharmacy, laboratory, and admission records.
A total of 286 orders for vancomycin were written for 205 patients, with 127 continuations. "To our surprise, 28% of vancomycin was used to treat respiratory infections," Dr Eng said. "Only a minority of these patients had MRSA infection confirmed by recovery of the organism from respiratory tract cultures."
The patients treated for respiratory sites were reviewed. Their average age was 72 years, 67% of cases were healthcare-associated or hospital-acquired, 39% of the orders were from intensive care units, and all had concurrent orders for antibiotics active against gram-negative bacteria. Only 13% of the patients had MRSA isolated from sputum for that admission. The average treatment period for patients was 7 days (range: 1–30 d).
The MRSA-culture-negative patients continued to receive vancomycin for a varying duration after the culture results were known.
Sixty percent of the patients improved clinically, 13% died within 7 days, and 20% died between Days 7 and 30. The MRSA rate among S aureus isolates was 50% for all cultures submitted.
All of the patients had vancomycin prescribed in accordance with the IDSA/ATS guidelines for patients at high risk for infection with multidrug-resistant bacteria. "It is possible that physicians' perceptions and interpretations of the current guidelines may lead to overuse of vancomycin for the treatment of pneumonia in hospitalized cases," Dr Eng said.
The current practice of vancomycin use in this clinical setting needs to be refined to prevent its overuse, Dr Eng concluded.