A nationwide evaluation of antibiotics consumption in Swedish intensive care units

Background Around 70% of all ICU patients are treated with antibiotics whereas up to 30% are suggested as unnecessary. Measuring antibiotic consumption is a prerequisite to improving its use and the purpose of the present investigation was to explore the use of antibiotics in Swedish ICUs. Material and methods Daily Defined Doses (DDDs) of antimicrobials delivered to Swedish ICUs, 2016-2018, were retrieved from Swedish pharmacies. From the Swedish Intensive Care Registry, we extracted data on a number of patient admissions, occupied bed days and Simplified Acute Physiology Score (SAPS)3. Results There was a similar annual rate of total DDDs per admission of 3.7, 3.5, 3.8 and total DDDs per 100 occupied bed days of 111, 111, and 115 but with an approximately 6-fold difference of DDDs per occupied bed days (61-366) between the ICUs. The most frequently used antibiotics were isoxazolyl penicillins (J01CF), penicillins with betalactamase-inhibitors, mainly piperacillin/tazobactam (J01CR), 3rd and 4th generation cephalosporins (J01DD + DE) and carbapenems (J01DH). Together these four classes accounted for a median of 52% of all antibiotic use. The use of carbapenems had a moderate positive correlation with the mean SAPS3 score (r = 0.6, p = .01). The use of other broad-spectrum antibiotics showed no such correlation. Conclusion Overall antibiotic use remained similar in Swedish ICUs during the years 2016-2018. Broad-spectrum antibiotics accounted for 50% of all DDDs but with a large inter-ICU variation which only partly can be explained by differences in patient case mix and microbial resistance. Presumably, it also reflects varying local prescribing practices.