A multicenter study of antimicrobial prescriptions for cats diagnosed with bacterial urinary tract disease

Objectives The aim of this study was to evaluate initial antimicrobial therapy in cats diagnosed with upper or lower bacterial urinary tract infections at veterinary practices in the USA and Canada. Methods Electronic medical records from a veterinary practice corporation with clinics in the USA and Canada were queried between 2 January 2016 and 3 December 2018. Feline patient visits with a diagnosis field entry of urinary tract infection, cystitis and pyelonephritis, as well as variation of those names and more colloquial diagnoses such as kidney and bladder infection, and where an antimicrobial was prescribed, were retrieved. Results Prescription data for 5724 visits were identified. Sporadic cystitis was the most common diagnosis (n = 5051 [88%]), with 491 (8.6%) cats diagnosed with pyelonephritis and 182 (3.2%) with chronic or recurrent cystitis. Cefovecin was the most commonly prescribed antimicrobial for all conditions, followed by amoxicillin–clavulanic acid. Significant differences in antimicrobial drug class prescribing were noted between practice types and countries, and over the 3-year study period. For sporadic cystitis, prescription of amoxicillin–clavulanic acid increased significantly and cefovecin decreased between 2016 and 2018, and 2017 and 2018, while fluoroquinolone use increased between 2017 and 2018. Conclusions and relevance The results indicate targets for intervention and some encouraging trends. Understanding how antimicrobials are used is a key component of antimicrobial stewardship and is required to establish benchmarks, identify areas for improvement, aid in the development of interventions and evaluate the impact of interventions or other changes.

239. Outcomes Associated with Empiric Aztreonam Use Compared to Anti-Pseudomonal β-lactams in Patients with Sepsis: An Opportunity for Allergy Stewardship

Background Aztreonam is often given to patients with a documented β-lactam allergy in lieu of a first-line anti-pseudomonal β-lactam (APBL). However, aztreonam offers no gram positive coverage and data suggest that gram negative organisms have lower susceptibility rates to this antibiotic than to APBLs. Septic patients are especially vulnerable to poor outcomes since inappropriate initial antimicrobial therapy has been shown to be an independent predictor of increased mortality. The purpose of this study was to determine whether septic patients treated with aztreonam experience inferior outcomes compared to those treated with an APBL. Methods This was a retrospective, multicenter, cohort study of all adult patients in metro Charlotte Atrium Health facilities treated for sepsis or septic shock from January 2014 to October 2017. Patients receiving either aztreonam or an APBL were identified using the system-wide sepsis database and enrolled in a 1:2 ratio. Patients were excluded if there was no infection-related discharge ICD-9 or ICD-10 code, if they received both aztreonam and an APBL in the first 8 hours, or if they received fewer than 2 doses of the study antibiotic. The primary endpoint was in-hospital mortality. Results A total of 194 patients received aztreonam and 388 patients received an APBL. β-lactam allergies were more common in patients who received aztreonam compared to APBL (97% vs. 14.2%, p < 0.01). In-hospital mortality rates were greater in the patients who received aztreonam vs. APBL (22.7% vs. 12.9%, p = 0.0025). After adjusting for APACHE II score, initial aztreonam exposure remained independently associated with hospital mortality (OR = 1.74, 95% CI: 1.0 – 2.8, p = 0.02). Additionally, we identified an increase in combination therapy with the use of aminoglycosides (28.9% vs. 12.4%, p < 0.0001) and fluoroquinolones (50.5% vs. 25.8%, p < 0.0001) in patients receiving aztreonam. No difference was found in overall length of stay or ICU length of stay. Conclusion In septic patients, the use of aztreonam as the backbone of antimicrobial therapy may result in increased mortality. This highlights the importance of stewardship interventions that obtain an accurate allergy history and encourage the use of APBL antibiotics whenever feasible. Disclosures Kelly E. Pillinger, PharmD, BCIDP, Pharmacy Times (Other Financial or Material Support, Speaker)

A Fulminant Case of Haemophilus influenzae Serotype F Meningitis in an Immunocompetent 3-Year-Old Boy

Of all encapsulated Haemophilus influenzae (Hi), serotype b (Hib) is considered as the potentially most virulent one for children. After vaccination was introduced in the 1990s, the incidence of this serotype has dropped dramatically. Other encapsulated forms such as Hi serotype a, c, d, e, f (Hia-Hif) are diagnosed rarely and mostly affect vulnerable patient groups. As serotyping is not performed routinely, the number of unreported cases is estimated to be even higher. Whereas several cases of Hif disease in children with favorable outcome were published, a 3-year-old boy diagnosed with this serotype died at our hospital despite initial antimicrobial therapy.

Appropriate antibiotic therapy in critically ill patients

Severe sepsis and septic shock are leading causes of morbidity and mortality in critically ill patients in and outside Intensive Care Units. Early hemodynamic and respiratory support, along with prompt appropriate antimicrobial therapy and source control of the infectious process are cornerstone management strategies to improve survival. Antimicrobial therapy should be as much appropriate as possible, since inappropriate initial antimicrobial therapy is associated with poorer outcome in different clinical settings. When prescribing antibiotic therapy, drug’s characteristics, along with dosing, pharmacokinetics, and pharmacodynamic properties related to the drug and to the clinical scenario should be well kept in mind in order to achieve maximal success.