Measure Description: Percentage of patients aged 18 years and older, who undergo an open cardiac procedure over 240 minutes duration and who receive initial cephalosporin or clindamycin administration within 60 minutes before surgical incision or who receive vancomycin within 60 to 120 minutes before surgical incision and receive an intravenous cephalosporin antibiotic re-doses at four-hour intervals or clindamycin re-doses at six-hour intervals.