Conformity with guidelines for antimicrobial prophylaxis against bacterial endocarditis

The extent to which prescribed antimicrobial prophylaxis against bacterial endocarditis conformed with American Heart Association (AHA) guidelines was determined and the frequency of nonconformity with specific elements of the guidelines was evaluated. Patients with conditions defined by AHA as placing them at risk for developing endocarditis were identified through medical records for a four-year period at an 850-bed hospital. Data about the procedures they underwent and prophylaxis prescribed were compared with the AHA guidelines. Conformity with the guidelines was evaluated according to whether prophylaxis was recommended, optional, or unnecessary; nonconformity with specific elements of the guidelines (indication, choice of antimicrobial, dose, dosage interval, timing, and duration) was also evaluated. The following variables were evaluated for possible association with nonconformity to the guidelines: patient's age and sex, penicillin allergy, use of a consultant, and whether the procedure was the first performed in the patient after identification of the cardiac condition. Of the 131 cases analyzed, 29 (22%) involved prophylaxis that conformed with the AHA guidelines. Conformity with the guidelines was significantly lower when prophylaxis was recommended or optional than when it was unnecessary. Nonconformity was most common with the following elements: indication, choice of antimicrobial, and dose. Recommended prophylaxis was given more often in children than in adults and more often before first procedures than before subsequent procedures. More of the regimens prescribed for children exceeded the recommended duration than those prescribed for adults. Unnecessary prophylaxis was given more often when a consultant was involved than when no consultant was involved. In hospitalized patients, conformity with AHA guidelines for antimicrobial prophylaxis against endocarditis was low.