Strategies for selecting antibiotics in intensive care units

The impact of antimicrobial stewardship program designed to shorten antibiotics use on the incidence of resistant bacterial infections and mortality

Reassessing the continuing need for and choice of antibiotics by using an antibiotic "time out'' program may reduce unnecessary treatment. This study aimed to explore the effect of an antibiotic stewardship program (ASP) on the antibiotics consumption, incidence of resistant bacterial infections and overall hospital mortality in a tertiary medical center during the study period 2012-2014. An ASP composed of multidisciplinary strategies including pre-prescription approval and post-approval feedback and audit, and a major "time out'' intervention (shorten the default antibiotic prescription duration) usage was introduced in year 2013. Consumption of antibiotics was quantified by calculating defined daily doses (DDDs). Interrupted time series (ITS) analysis was used to explore the changes of antibiotics consumption before and after intervention, accounting for temporal trends that may be unrelated to intervention. Our results showed that following the intervention, DDDs showed a decreased trend in overall (in particular the major consumed penicillins and cephalosporins), in both intensive care unit (ICU) and non-ICU, and in non-restrictive versus restrictive antibiotics. Importantly, ITS analysis showed a significantly slope change since intervention (slope change p value 0.007), whereas the incidence of carbapenem-resistant and vancomycin-resistant pathogens did not change significantly. Moreover, annual overall mortality rates were 3.0%, 3.1% and 3.1% from 2012 to 2014, respectively. This study indicates that implementing a multi-disciplinary strategy to shorten the default duration of antibiotic prescription can be an effective manner to reduce antibiotic consumption while not compromising resistant infection incidence or mortality rates.

Antibiotic Resistant Bacterial Pathogens Associated with Blood Stream Infections and Urinary Tract Infections among Intensive Care Unit Patients

Blood Stream Infection (BSI) and Urinary Tract Infection (UTI) being leading causes of morbidity and mortality represent a common complication among critically ill patients. During the last decade, clinicians have observed a rising occurrence of BSIs due to bacterial resistance. Likewise, catheter-associated UTI is a main cause of morbidity and mortality affecting all age groups. Coliforms happen to be the prominent pathogens among our ICU admitted patients. It was alarming to notice 42.9% resistance to tigecycline among K. pneumoniae isolated from blood. K. pneumoniae isolates cultured from urine of ICU patients uniformly displayed 75% resistance to ciprofloxacin, ceftriaxone, cefoxitin and cefepime. Interestingly, it is of respite to observe 85.7% K. pneumoniae isolated from blood and 75% K. pneumoniae isolated from urine being susceptible to a conventional antibiotic, gentamicin. Escherichia coli isolated from urine were 100% susceptible to carbapenems and 91.75% were susceptible to tigecycline. Overall, 90% of Pseudomonas aeruginosa were susceptible to nitrofurantoin. The rapid spread of these MDR pathogens demands for national and regional guidelines. Policies to treat ICU related infections in UAE should be designed based on local microbiological data and resistance profiles of pathogens.

Antibiotic Prescribing in Response to Bacterial Isolates in the Intensive Care Unit

This study aimed to identify potential knowledge-performance gaps in antibiotic prescribing for bacterial isolates in the Intensive Care Unit (ICU) in order to guide the development of interventions such as antibiotic policies, decision support, and improved systems for communication between the laboratory and the bedside. A prospective observational cohort study of all patients admitted to a mixed medical/surgical ICU was undertaken over a six-month period in an Australian adult tertiary hospital. From a cohort of 524 patients, 108 had 303 isolates that were eligible for inclusion. Overall, 14.3% and 30.8% of sterile and non-sterile isolates respectively were associated with inadequate initial antibiotic therapy after identification of the bacteria. After sensitivity results were available inadequate directed therapy was observed in 4.0% and 21.3% of sterile and non-sterile isolates respectively. Problems were most commonly associated with isolates of Pseudomonas spp., Stenotrophomonas spp., Acinetobacter spp., S. aureus, enterococci and group III Enterobacteriaceae. Inadequate antibiotic therapy was found to be independently associated with prolonged length of ICU stay. Narrower spectrum antibiotic therapy was potentially available for 30% of isolates after sensitivity results were known. We conclude that there is scope to improve antibiotic prescribing in the ICU by providing clinicians with access to information regarding local susceptibility patterns and intrinsic resistance of bacteria, and spectra of antibiotic cover. Timely notification of laboratory results at the point of care may also facilitate improved prescribing performance.

Is there a rationale for the continuous infusion of cefepime? A multidisciplinary approach

This review is the fruit of multidisciplinary discussions concerning the continuous administration of beta-lactams, with a special focus on cefepime. Pooling of the analyses and viewpoints of all members of the group, based on a review of the literature on this subject, has made it possible to test the hypothesis concerning the applicability of this method of administering cefepime. Cefepime is a cephalosporin for injection which exhibits a broader spectrum of activity than that of older, third-generation cephalosporins for injection (cefotaxime, ceftriaxone, ceftazidime). The specific activity of cefepime is based on its more rapid penetration (probably due to its zwitterionic structure, this molecule being both positively and negatively charged) through the outer membrane of Gram-negative bacteria, its greater affinity for penicillin-binding proteins, its weak affinity for beta-lactamases, and its stability versus certain beta-lactamases, particularly derepressed cephalosporinases. The stability of cefepime in various solutions intended for parenteral administration has been studied, and the results obtained demonstrated the good compatibility of cefepime with these different solutions. These results thus permit the administration of cefepime in a continuous infusion over a 24-h period, using two consecutive syringes.

Antibiotic resistance

Widespread resistance problems exist today in a global sense because of the incorporation of antibiotics with a high resistance potential into animal feeds and because of the uncontrolled use of antibiotics with a high resistance potential in the clinical setting. The only proven method of controlling nonoutbreak resistance problems in hospitals is to limit the hospital formulary to antibiotics with little or no resistance potential. The control of multiresistant organisms in outbreaks occurring in hospitals is best contained using appropriate infection control containment measures. Physicians treating infections in the community, with all other factors being equal, should preferentially select antibiotics with a low resistance potential. The titles and headings of much of the resistance literature are misleading. Articles should not contain fluoroquinolone resistant in the title when ciprofloxacin-resistant organisms are described. Many articles concerning penicillin-resistant pneumococci are entitled fluoroquinolone-resistant S. pneumoniae. These articles describe ciprofloxacin-resistant S. pneumoniae and not resistance to other fluoroquinolones. The same error is perpetuated in describing third-generation cephalosporins and carbapenems. Virtually all of the resistance problems associated with third-generation cephalosporins and carbapenems are due to ceftazidime or imipenem. More precise titling in the literature would remind physicians that antibiotic resistance is related to a specific agent and not class phenomena.