The relationship between hospital or surgeon volume and outcomes in lower limb vascular surgery in the United Kingdom and Europe

Introduction Peripheral vascular disease is a major cause of death and disability. The extent to which volume influences outcome of lower limb (LL) vascular surgery remains unclear. This review evaluated the relationship between hospital/surgeon volume and outcome in LL surgery. Methodology Electronic databases; Medline, Embase, the Cochrane Library Databases, Science Citation Index, and CINAHL, proceedings from conferences, citations, and references of included studies were searched. Studies from Europe, of adults undergoing LL vascular surgery reporting outcomes by hospital or surgeon volume were included. Quality of studies was assessed using a modified ACROBAT-NRSI(Robins1) tool. Association between hospital/surgeon volume and outcome were summarised using tables. Results Nine studies from different European countries, comprising 67,445 patients who had undergone diverse LL surgeries were included. Increase in hospital/surgeon volume was associated with a decrease in amputations. The evidence on an association between hospital/surgeon volume and mortality was contradictory, but mortality and amputations may co-vary by hospital volume. There were an insufficient number of studies reporting on the other variables to draw firm conclusions; but their results suggest high volume hospitals may undertake more repeated surgeries/revascularisations and limb salvage. The impact of hospital/surgical volume on adverse events and length of hospitalisation could not be determined. Conclusion High volume hospitals/surgeons may undertake fewer amputations and mortality and amputations may co-vary. The finding that hospital and surgeon volume affected the number of secondary amputations has implications on re-organisation of vascular surgery services. However due to the small number and poor quality of some of the included studies, decisions on reorganisation of LL vascular surgery services should be supplemented by results from clinical audits. There is need for standardisation of definition of volume stratification of outcomes by patient’s clinical conditions

Seasonal azithromycin use in paediatric protracted bacterial bronchitis does not promote antimicrobial resistance but does modulate the nasopharyngeal microbiome

Protracted bacterial bronchitis (PBB) causes chronic wet cough for which seasonal azithromycin is increasingly used to reduce exacerbations. We investigated the impact of seasonal azithromycin on antimicrobial resistance and the nasopharyngeal microbiome. In an observational cohort study, 50 children with PBB were enrolled over two consecutive winters; 25/50 at study entry were designated on clinical grounds to take azithromycin over the winter months and 25/50 were not. Serial nasopharyngeal swabs were collected during the study period (12–20 months) and cultured bacterial isolates were assessed for antimicrobial susceptibility. 16S rRNA-based sequencing was performed on a subset of samples. Irrespective of azithromycin usage, high levels of azithromycin resistance were found; 73% of bacteria from swabs in the azithromycin group vs. 69% in the comparison group. Resistance was predominantly driven by azithromycin-resistant S. pneumoniae, yet these isolates were mostly erythromycin susceptible. Analysis of 16S rRNA-based sequencing revealed a reduction in within-sample diversity in response to azithromycin, but only in samples of children actively taking azithromycin at the time of swab collection. Actively taking azithromycin at the time of swab collection significantly contributed to dissimilarity in bacterial community composition. The discrepancy between laboratory detection of azithromycin and erythromycin resistance in the S. pneumoniae isolates requires further investigation. Seasonal azithromycin for PBB did not promote antimicrobial resistance over the study period, but did perturb the microbiome