Antibiotic Prescribing Evaluation in an Outpatient Hemodialysis Clinic

Abstract

Background Empiric vancomycin treatment is frequently used in hemodialysis (HD) patients because of ease of administration when methicillin-resistant Staphylococcus aureus (MRSA) infection is suspected. Differing rates of MRSA indicate that empiric antibiotic treatment should be based on a center-specific antibiogram. Objective To develop a center-specific antibiogram, evaluate antibiotic prescribing patterns, and determine areas of improvement in infection treatment. Methods The antibiogram was constructed from culture and susceptibility (C&S) data from January through December 1999. Evaluation of prescribing habits was based on 3 criteria: (1) Hospital Infection Control Practices Advisory Committee and Centers for Disease Control and Prevention guidelines; (2) vancomycin for 1 dose followed by appropriate antibiotic based on C&S results; and (3) C&S obtained with more than 1 dose of antibiotic. Results HD was provided to 161 patients during the study period. Antibiotics were empirically prescribed 104 times in 62 different patients. Cultures were obtained 122 times, and 67 different isolates were identified. Gram-positive organisms and gram-negative organisms accounted for 77.6% and 22.4% of isolates, respectively. Gram-positive organisms were identified as Staphylococcus spp. (53.8%); 17.9% of the staphylococcal isolates were MRSA strains. No isolates of vancomycin-resistant enterococcus were identified. Based on the antibiogram, empiric antibiotic therapy within our center should be 1 dose each of vancomycin and an aminoglycoside. Empiric vancomycin was used 71 times. When criterion I is used, 12 prescriptions (16.9%) were considered appropriate. When criterion II and adjustment for MRSA reported for our center were used, 46 (64.8%) vancomycin prescriptions were considered appropriate. Forty-one patients had more than 1 dose of antibiotic therapy, and 18 (43.9%) of those patients did not have C&S data obtained as prescribed by criterion III. Areas of prescribing improvement include obtaining a C&S in all suspected infections prior to empiric therapy and a more aggressive antibiotic switch based on C&S results. Conclusions Antibiograms can be used to determine appropriate empric antibiotic therapy and identify areas of improvement.