Background: Antibiotics (ATB) are drugs widely used in hospitalized newborns. The indiscriminate use of ATBs promote the rise of resistant bacteria to the most commonly indicated antimicrobials. In addition, ATB prescription presents associations to morbidity, such as bronchopulmonary dysplasia, necrotizing enterocolitis, late sepsis and even death. All of the above leads to an increase in health care costs.
Aim: To record and to evaluate trends of antibiotic use over time in hospitalized NB in the Neonatology Unit at Dr. Sótero del Río Hospital, in order to objectify the changes in the usual practice of the ATM indication. A secondary objective was to assess its impact on antimicrobial resistance.
Methods: Cohort, observational, prospective unicenter study which included all hospitalized patients between January 2011 and December 2014. Birth weight, hospitalization days, ATB indication and days of ATB use were recorded for each patient. The use of ATB was quantified by means of different rates; days of indication of one or more ATBs for global consumption (RUA), total sum of days of use (TSUA) and for the most frequently used ATBs. Each calculated rate for 100 days hospitalized. In addition, the antimicrobial susceptibility of the most frequently isolated bacteria in our service: coagulase-negative Staphylococcus (SCN) and Gram-negative bacilli (BGN) were recorded continuously.
Results: The 34.7% of the hospitalized patients received some type of antimicrobial agent. ATBs were 32.3% of medicines used. The most widely used was ampicillin (with 20.2% of the total) and cefadroxyl (with 11.6%). The RUA did not change during the study time, but STUA decreased by 10.7% between 2011 and 2014 with p < 0.05. When subgroup analyzes were divided by weight ranges, in the < 750 g group, the use of vancomycin decreased in use by 9.9% and an increase of 18.8% for metronidazole was observed. On the other hand, there was an increase in the use of the piperacillin-tazobactam regimen in the range > 1,500 g. When evaluating antimicrobial susceptibility, there was a decrease in susceptibility for oxacillin in SCN between 2011 and 2014 from 27% to 10.3% respectively. In addition, for Gram negative there was a decrease from 76.9% to 40.5% in susceptibility to third generation cephalosporins, mainly due to Klebsiella pneumoniae, which became the predominantly isolated BGN with an increase of 6.7% to 50% between 2011 and 2014, respectively. For K. pneumoniae the loss of susceptibility to third generation cephalosporins decreased from 77% to 22%. Finally, amikacin showed an activity over 85% in all BGNs between 2011 and 2014.
Conclusions: It is advisable to plan and to maintain a continuous record of ATB consumption, as well as therapy and prophylaxis, being categorized by ATB type and range of newborn weight. It is of considerable importance to analyze and to evaluate the susceptibility of microorganisms. It is essential that an interdisciplinary team prepare this recording, and to continuously provide feedback to professionals who maintain the functioning of neonatal care units.