A Trial of Discontinuation of Empiric Vancomycin Therapy in Patients with Suspected Methicillin-Resistant Staphylococcus aureus Health Care-Associated Pneumonia

Abstract

f Healthcare-associated pneumonia (HCAP) guidelines recommend de-escalating initial antibiotic therapy based on results from lower-respiratory-tract cultures. In the absence of adequate lower respiratory cultures, physicians are sometimes reluctant to discontinue empirical vancomycin, which is given for suspected methicillin-resistant Staphylococcus aureus (MRSA) HCAP. We evaluated a strategy of discontinuing vancomycin if both nasal and throat cultures were negative for MRSA when lower-respiratory-tract cultures were not available. An antimicrobial stewardship team identified patients receiving empirical vancomycin for suspected or proven HCAP but for whom adequate lower-respiratory-tract cultures were not available. Nasal and throat swab specimens were obtained and plated on MRSA selective media. If both nasal and throat MRSA cultures were negative, the stewardship team recommended discontinuation of empirical vancomycin. Demographic and clinical aspects, a clinical pulmonary infection score (CPIS) on the day of the stewardship recommendation, and mortality of patients for whom vancomycin was discontinued were obtained by retrospective chart review. A convenience sample of 91 patients with nasal and throat cultures negative for MRSA in the absence of adequate respiratory cultures had empirical vancomycin therapy discontinued. A retrospective review revealed that 88 (97%) patients had a CPIS of <6 on the day of the stewardship recommendation. In-hospital mortality (7.7%) was similar to that of a previous study of de-escalation of antibiotics in pneumonia patients without adequate cultures. In the absence of adequate lower-respiratory-tract cultures, it is reasonable to discontinue empirical vancomycin HCAP therapy in patients with negative MRSA nasal and throat cultures and a CPIS of <6.

Inappropriate Continued Empirical Vancomycin Use in a Hospital with a High Prevalence of Methicillin-Resistant Staphylococcus aureus

“…Some interventions to increase the appropriateness of continued empirical vancomycin use at 72 to 96 h would be sensible and helpful in reducing the amount of vancomycin prescribed, considering that inappropriately continued vancomycin use makes up one-quarter of the vancomycin prescribed. The safety of vancomycin discontinuation in the absence of documented MRSA has been suggested by multiple studies (26,27), and Hamilton et al showed that a continuation form at 72 h was effective in reducing inappropriately continued vancomycin use (24). In cases of suspected ventilator-associated pneumonia, antibiotic discontinuation strategies based on clinical criteria were successful in safely reducing antibiotic treatment duration (28,29).…”

Using MRSA Screening Tests To Predict Methicillin Resistance in Staphylococcus aureus Bacteremia

“…However, the use of MRSA screening tests to guide antibiotic therapy remains poorly studied. Prior studies have evaluated their use in multiple situations, including intra-abdominal (10), postoperative (11), respiratory (12,13), and overall documented clinical infections (14). There is little published on the use of MRSA screening in bloodstream infection.…”

Rapid Automated Microscopy for Microbiological Surveillance of Ventilator-associated Pneumonia

“…Prolonged broad-spectrum empiric therapy can also contribute to the selection and spread of multidrug resistant organisms (MDROs) (16,17). Rapid deescalation to optimal therapy based on resistance testing (11,18,19) is therefore important for antimicrobial stewardship.…”