Evaluating the long-term impact of an antimicrobial stewardship programme in a Central London mixed medical and surgical intensive care unit.

Background: Antimicrobial overuse causes increased antimicrobial resistance in ICUs; antimicrobial stewardship programmes (ASPs) aim to optimize usage. Following an MDR Acinetobacter baumannii (MRAb) outbreak in 2008, an ASP was implemented at a London ICU, and then continued as a long-term programme. This study aimed to determine long-term changes in antimicrobial prescribing 9 years on. Methods: Data were collected from ICU patients in 2008 immediately before ASP implementation, and thereafter for 6 month cohort periods in 2010-2011, 2012 and 2017. Antimicrobial usage in DDD per 1000 occupied bed days (OBD) were compared. Multivariate linear regression models for antimicrobial days were fitted, adjusting for APACHE II score and patient days. Antimicrobial resistance in Pseudomonas aeruginosa (as an indicator organism) was compared across cohort periods. Findings: Across 400 patients over 9 years, antimicrobial use changed significantly (P < 0.011) and remained lower in all post-ASP cohorts compared with pre-ASP [(2008; 1827 DDD/1000 OBD), (2010; 1264 DDD/1000 OBD), (2012; 1270 DDD/1000 OBD) and (2017; 1566 DDD/1000 OBD)]. There was reduction in usage of all antimicrobial classes except ß-lactams (where there was no significant increase nor decrease, P = 0.178) and aminoglycosides (where there was a significant increase in usage, P < 0.0001). The latter was temporally associated with restrictions on specific carbapenems. There was an increase in carbapenem-resistant P. aeruginosa in 2012 only (P = 0.028) but not subsequently. Conclusions: Following ASP implementation after an outbreak of MRAb, reduced antimicrobial prescribing was maintained 9 years on. We identify several factors influencing successful long-term maintenance of ASPs in ICUs.

Impact of inhalation injury on outcomes in critically ill burns patients: 12-year experience at a regional burns centre.

INTRODUCTION: Burns inhalation injury increases the attributable mortality of burns related trauma. However, diagnostic uncertainties around bronchoscopically graded severity, and its effect on outcomes, remain. This study evaluated the impact of different bronchoscopic burns inhalation injury grades on outcomes. METHODS: A single-centre cohort study of all patients admitted to the London Burns centre intensive care unit (BICU) over 12 years. Demographic data, burn and burns inhalation injury characteristics, and ICU-related parameters were collected retrospectively. The primary outcome was mortality. Secondary outcomes were hospital and ICU lengths of stay. The impact of pneumonia was determined. Univariate and multivariable Cox's proportional hazards regression analyses informed factors predicting mortality. RESULTS: Burns inhalation injury was diagnosed in 84 of 231 (36%) critically ill burns patients; 20 mild (grade 1), 41 severe (grades 2/3) and 23 unclassified bronchoscopically. Median (IQR) total body surface area burned (TBSA) was 20% (10-40). Mortality was significantly higher in patients with burns inhalation injury vs those without burns inhalation injury (38/84 [45%] vs 35/147 [24%], p < 0.001). Patients with pneumonia had a higher mortality than those without (34/125 [27%] vs 8/71 [11%], p = 0.009). In multivariable analysis, severe burns inhalation injury significantly increased mortality (adjusted HR=2.14, 95%CI: 1.12-4.09, p = 0.022), compared with mild injury (adjusted HR=0.58, 95% CI: 0.18-1.86, p = 0.363). Facial burns (adjusted HR=3.13, 95%CI: 1.69-5.79, p < 0.001), higher TBSA (adjusted HR=1.05, 95%CI: 1.04-1.06, p < 0.001) and older age (adjusted HR=1.04, 95%CI: 1.02-1.07, p < 0.001) also independently predicted mortality, though pneumonia did not. CONCLUSIONS: Severe burns inhalation injury is a significant risk factor for mortality in critically ill burns patients. However, pneumonia did not increase mortality from burns inhalation injury. This work confirms prior implications of bronchoscopically graded burns inhalation injury. Further study is suggested, through registries, into the diagnostic accuracy and reliability of bronchoscopy in burns related lung injury.