Antimicrobial Stewardship in the intensive care unit setting is a difficult task due to diagnostic uncertainty and perceived high-risk of poor outcomes in case of delayed or inappropriate treatment. Although novel diagnostics and other strategies have been proposed to improve antimicrobial use, their clinical effectiveness in real-world settings has been suboptimal.

We designed a critical interpretative synthesis of the literature, which allows the combination of quantitative and qualitative studies to revise and critique concepts used in Antimicrobial Stewardship efforts in the ICU setting. We searched the literature in duplicate with a sensitive strategy to identify main concepts, and we developed a main theme and conceptual framework after identifying the main concepts and strategies.

After screening 41,192 titles and abstracts and reviewing 1,335 full-text manuscripts, we selected 29 main manuscripts for this synthesis. We identified that classical concepts, such as the use of broad-spectrum antibiotics followed by de-escalation and the use of biomarkers of infection and novel diagnostics, although with face validity and supported by efficacy studies, carry a high risk of being ineffective in real-world settings. We argue that this discrepancy is due to cognitive biases in antimicrobial decision-making in the ICU setting, including risk-aversion behavior, diagnostic momentum, premature closure, therapeutic momentum, hyperbolic discounting, commission bias, and anchoring bias, among others, which drive intensivists towards overdiagnosis and overtreatment of infection.

Incorporation of the cognitive theory of decision-making in future stewardship efforts is necessary in the ICU setting along with traditional stewardship interventions.

Unnecessary urine cultures contribute to inappropriate antibiotic use, antimicrobial resistance, and Clostridioides difficile infection, particularly when asymptomatic bacteriuria (ASB) is misclassified as infection. We evaluated the diagnostic stewardship impact of an algorithm-based best practice alert (BPA) embedded in the electronic medical record (EMR) to guide urine testing in hospitalized adults.

This prospective quality improvement study was conducted at a 740-bed tertiary care hospital. The BPA triggered when urinalysis with reflex to culture (UACC) was ordered for patients admitted ≥48 hours, guiding clinicians through an algorithm-based ordering workflow. Monthly rates of UACC and pan-culturing were compared between a 12-month pre-intervention period and a 12-month post-intervention period using interrupted time series (ITS) and Mood’s median two-sample test. Gram-negative rod (GNR) bacteremia rates were monitored for safety.

Urine testing decreased from 6.45 to 4.41 tests per 1,000 patient-days (31.6% reduction; P < .01), and pan-culturing decreased from 3.47 to 2.70 per 1,000 patient-days (22.2% reduction; P < .01). ITS showed declining trends both before and after implementation, without significant immediate changes in level or slope following the intervention. CAUTI rates remained stable (0.91 vs 0.82 per 1,000 catheter-days; P = .68), as did rates of gram-negative rod bacteremia (0.47 vs 0.70 per 1,000 patient-days; P = .22). Algorithm adherence averaged 63.9% and increased over time (P < .01). CAUTI cases classified as potential asymptomatic bacteriuria declined from 31.8% to 25.0% (P = .68).

An EMR-integrated, algorithm-based BPA coincided with sustained lower urine testing and pan-culturing rates without adverse safety signals within the context of existing downward trends. Ongoing monitoring is needed to sustain adoption and appropriate use.

To understand how the workflows and infection prevention and control (IPC) practices of certified nursing assistants (CNAs) during high-contact resident care activities contribute to multidrug-resistant organism (MDRO) transmission in nursing homes.

We conducted 10 high-fidelity simulations of two high-contact resident care activities, bed bathing and incontinence care, with CNAs from long-term or mixed-care units. Four genetic variants of λ phage were applied to select surfaces prior to simulations and subsequently sampled from the environment, residents, supplies, and CNAs. Simulations were video recorded and analyzed for patterns of hand-to-surface contact and performance of IPC practices, including hand hygiene, personal protective equipment use, and environmental surface cleaning or disinfection.

A median of 11.5 transmission events occurred per simulation. Most events (60%) occurred within residents’ immediate environments, reflecting how CNAs frequently transitioned between a resident, their surroundings, and care supplies, combined with infrequent hand hygiene and surface disinfection. Contamination of CNA scrubs and hands accounted for 24% of events, primarily from bed bathing, which involved frequent contact without a gown. Transmission to shared objects (e.g., linen bin, trash can, wheelchair) accounted for 16% of events and created additional opportunities for transmission between residents. Transmission between residents or their immediate environments was rare but typically associated with workflow disruptions from limited-supply availability.

In high-fidelity simulations of high-contact resident care activities, transmission of surrogate markers for MDROs closely followed the workflows of CNAs. This method identifies potential transmission pathways and interventions for mitigating MDRO spread in nursing homes.