Modelling antimicrobial resistance transmission to guide personalized antimicrobial stewardship interventions and infection control policies in healthcare setting: a pilot study.

Infection control programs and antimicrobial stewardship have been proven effective in reducing the burden of diseases due to multidrug-resistant organisms, but quantifying the effect of each intervention is an open issue. For this aim, we propose a model to characterize the effect of interventions at single ward level. We adapted the Ross-Macdonald model to describe hospital cross-transmission dynamics of carbapenem resistant Klebsiella pneumoniae (CRKP), considering healthcare workers as the vectors transmitting susceptible and resistant pathogens among admitted patients. The model parameters were estimated from a literature review, further adjusted to reproduce observed clinical outcomes, and validated using real life data from a 2-year study in a university hospital. The model has been further explored through extensive sensitivity analysis, in order to assess the relevance of single interventions as well as their synergistic effects. Our model has been shown to be an effective tool to describe and predict the impact of interventions in reducing the prevalence of CRKP colonisation and infection, and can be extended to other specific hospital and pathological scenarios to produce tailored estimates of the most effective strategies.

How to 'SAVE' antibiotics: effectiveness and sustainability of a new model of antibiotic stewardship intervention in the internal medicine area.

BACKGROUND: Antibiotic stewardship (AS) is a cornerstone of the fight against antimicrobial resistance; however, evidence on the best practice to improve antibiotic prescription in various hospital settings is still scarce. This study aimed to measure the efficacy of a non-restrictive AS intervention in the internal medicine area of a tertiary-care hospital across a 3-year period. METHODS: The intervention comprised a 3-month 'intensive phase' based on education and guidelines provision, followed by 9 months of audits and feedback activities. The primary outcome was the overall antibiotic consumption measured as days of therapy (DOTs) and defined daily doses (DDDs). Secondary outcomes were carbapenem and fluoroquinolone consumption, all-cause in-hospital mortality, length of stay, incidence of Clostridioides difficile and carbapenem-resistant Enterobacterales bloodstream infections (CRE-BSIs). All outcomes were measured in the intervention wards comparing the pre-phase with the post-phase using an interrupted time-series model. RESULTS: A total of 145 337 patient days (PDs) and 14 159 admissions were included in the analysis. The intervention was associated with reduced DOTs*1000PDs (-162.2/P = 0.005) and DDDs*1000PDs (-183.6/P ≤ 0.001). A sustained decrease in ward-related antibiotic consumption was also detected during the post-intervention phase and in the carbapenem/fluoroquinolone classes. The intervention was associated with an immediate reduction in length of stay (-1.72 days/P < 0.001) and all-cause mortality (-3.71 deaths*100 admissions/P = 0.002), with a decreasing trend over time. Rates of Clostridioides difficile infections and CRE-BSIs were not significantly impacted by the intervention. CONCLUSIONS: The AS intervention was effective and safe in decreasing antibiotic consumption and length of stay in the internal medicine area. Enabling prescribers to judicious use of antimicrobials through active participation in AS initiatives is key to reach sustained results over time.

Rejection of hemolyzed samples can jeopardize patient safety.

INTRODUCTION: In vitro hemolysis is the primary cause of sample/test rejection by the laboratory. CASE REPORT: A 10-year-old, admitted with an asthma attack in the emergency-room, medicated with albuterol sulphate (intravenous bronchodilator that could induce hypokalemia), needed laboratory test monitoring. The physician prescribed the technical-nurse to perform blood sampling for: complete blood count, electrolytes, glucose, and blood gas analysis-within 30min after therapy. Samples were delivered to laboratory with a note "I had difficult to locate an appropriate access to perform the blood collection". LABORATORY RESULTS: Glucose: 4.77 mmol/L. Complete blood count revealed discreet eosinophilia 0.13x109/L, and thrombocytopenia 18x109/L. However, platelet clumps were observed in peripheral blood smear. Blood gas analysis was unreported, laboratory informed that sample had micro clots.Electrolytes: laboratory did not report the results; sample hemolyzed. 0.9 g/L of free hemoglobin is the cut-off defined by the laboratory; the sample presented 2.3 g/L of free hemoglobin. 3.9 mmol/L of potassium was the unreported result vs 2.1 mmol/L in the new sample.Briefly, the laboratory technician was trained to hide potassium results on hemolyzed sample due to the potential overestimation. Even if the hemolyzed sample presented a potassium value close to the lower reference range value (3.5-5.1 mmol/L), reporting the potassium result could allow the physician starting proper therapy to revert the hypokalemia by albuterol sulfate. CONCLUSION: The laboratory should be aware of the clinical patient conditions and of the related physician needs, before hiding results. Therefore, both the laboratory and the clinic personnel should communicate in order to guarantee the patient safety.