Economic benefit of appropriate timing of vancomycin prophylaxis in patients undergoing cardiovascular surgery.

STUDY OBJECTIVE: To determine if appropriate timing of vancomycin prophylaxis in patients undergoing cardiovascular surgery results in an economic benefit by assessing the differences in total duration of hospitalization and hospital costs based on infusion start time in relation to first surgical incision.

DESIGN: Prospective, observational study.

SETTING: Tertiary care medical center.

PATIENTS: A total of 1666 patients undergoing coronary artery bypass graft (CABG) and/or valve replacement surgery who received prophylactic vancomycin.

MEASUREMENTS AND MAIN RESULTS: Appropriateness of vancomycin prophylaxis timing, based on national guidelines defining appropriate timing as start time of infusion ranging from 16-120 minutes before surgery start time, was prospectively monitored. The timing of vancomycin administration was grouped as follows: 0-15 minutes (11 patients), 16-60 minutes (156), 61-120 minutes (772), or more than 120 minutes (727) before incision. Antibiotic timing was appropriate in 928 patients and inappropriate in 738 patients. Length of hospital stay and total hospital costs were compared based on appropriateness of therapy by using multivariate linear regression and validated with a Heckman two-stage model. Median numbers of hospitalization and intensive care unit days were significantly fewer in patients given appropriate prophylaxis at an appropriate time (9 and 2 days, respectively) compared with inappropriate time (10 and 3 days, respectively, p<0.001 for both analyses). Hospital costs were significantly lower in patients who had appropriate timing of antibiotic prophylaxis (median $25,321, interquartile range [IQR] $19,429-35,471) compared with inappropriate timing (median $29,475, IQR $21,507-46,488, p<0.001). Multivariate linear regression and a Heckman two-stage model confirmed that appropriate antibiotic prophylaxis timing was associated with decreased hospitalization duration and hospital costs.

CONCLUSION: In patients undergoing CABG or valve replacement surgery, the administration of vancomycin 16-120 minutes before incision significantly reduced patient hospitalization duration and total hospital costs.