Time to First Culture Positivity Among Critically Ill Adults With Methicillin-Resistant Growth in Respiratory or Blood Cultures.

For critically ill adults receiving empirical vancomycin, the duration of negative cultures after which vancomycin may be discontinued without risking subsequent growth of methicillin-resistant (MRSA) remains unknown. We hypothesized that if sputum cultures did not grow MRSA or blood cultures did not grow Gram-positive cocci on Gram stain by 48 hours, those cultures would not subsequently demonstrate MRSA. We conducted an ancillary analysis from patients enrolled in the Isotonic Solutions and Major Adverse Renal Events Trial (SMART).