The use of routinely collected electronic prescribing data to benchmark intravenous antibiotic use between two tertiary paediatric haematology-oncology inpatient units: a retrospective study.

Background: High-quality systematic data on antimicrobial use in UK inpatient paediatric haematology-oncology services are lacking, despite this population being at high risk from antimicrobial exposure and resistance. Objectives: We conducted a retrospective study to demonstrate how routinely collected electronic prescribing data can address this issue. Patients and methods: This retrospective study describes and compares IV antibiotic consumption between two UK paediatric haematology-oncology inpatient units, between 2018 and 2022. Both sites provide similar services and receive proactive antimicrobial stewardship input. Data were extracted from each site's antimicrobial surveillance system, which report monthly days of therapy (DOT) per 100 patient-days (PD). Consumption was reported for specific and total antibiotics. Trends were modelled using linear regression and autoregressive moving average models. Results: Total IV antibiotic consumption at each site was similar. Median monthly DOT per 100 PD were 25.9 (IQR: 22.1-34.0) and 29.4 (24.2-34.9). Total antibiotic use declined at both sites, with estimated annual yearly reductions of 3.52 DOT per 100 PD (95% CI: 0.46-6.59) and 2.57 (1.30-3.85). Absolute consumption was similar for carbapenems, piperacillin/tazobactam and aminoglycosides, whilst ceftriaxone and teicoplanin demonstrated approximately 3-fold relative differences in median monthly consumption. Meropenem, piperacillin/tazobactam, teicoplanin, vancomycin and gentamicin all demonstrated statistically significant reductions in use over time at either one or both sites, although this was most marked for piperacillin/tazobactam and vancomycin. Conclusions: Routinely collected electronic prescribing data can aid benchmarking of antibiotic use in paediatric haematology-oncology inpatients, highlighting areas to target stewardship strategies, and evaluating their impact. This approach should be rolled out nationally, and to other high-risk groups.

Cationic Nanoliposomes Are Efficiently Taken up by Alveolar Macrophages but Have Little Access to Dendritic Cells and Interstitial Macrophages in the Normal and CpG-Stimulated Lungs.

The purpose of this study was to assess whether cationic nanoliposomes could address tumor vaccines to dendritic cells in the lungs in vivo. Nanoliposomes were prepared using a cationic lipid, dimethylaminoethanecarbamoyl-cholesterol (DC-cholesterol) or dioleoyltrimethylammoniumpropane (DOTAP), and dipalmitoylphosphatidylcholine (DPPC), the most abundant phospholipid in lung surfactant. The liposomes presented a size below 175 nm and they effectively entrapped tumor antigens, an oligodeoxynucletotide containing CpG motifs (CpG) and the fluorescent dye calcein used as a tracer. Although the liposomes could permanently entrap a large fraction of the actives, they could not sustain their release in vitro. Liposomes made of DOTAP were safe to respiratory cells in vitro, while liposomes composed of DC-cholesterol were cytotoxic. DOTAP nanoliposomes were mainly taken up by alveolar macrophages following delivery to the lungs in mice. Few dendritic cells took up the liposomes, and interstitial macrophages did not take up liposomal calcein more than they took up soluble calcein. Stimulation of the innate immune system using liposomal CpG strongly enhanced uptake of calcein liposomes by all phagocytes in the lungs. Although a small percentage of dendritic cells took up the nanoliposomes, alveolar macrophages represented a major barrier to dendritic cell access in the lungs.