A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Aetiological diagnosis in new adult outpatients with bronchiectasis:role of predictors derived from real life experience

Background: In adult patients with bronchiectasis (BE) the identification of the underlying aetiology may be difficult. In a new patient with BE the performance of a panel of tests is recommended, even though this practice may be expensive and the level of evidence supporting is low. We aimed to identify a panel of variables able to predict the aetiological diagnosis of BE. Methods: Our prospective study derived from our real-life experience on the management of adult stable BE outpatients. We recorded variables concerning clinical, radiological, microbiological and laboratory features. We identified five groups of aetiological diagnosis of BE (idiopathic, post-infective, COPD, asthma and non-common diseases [immunodeficiency or other rare conditions]). Multivariate models were used to identify predictors of each aetiological diagnosis. The suitability of performing a specific test for the diagnosis was also considered. Results: We enrolled 354 patients with a new diagnosis of BE. Patients with different aetiological causes differed significantly with regard to age, sex, smoking habit, comorbidities, dyspnoea perception, airflow obstruction and severity scores. Various predictors were assessed, including sex, previous respiratory infections, diffuse localization of BE, risk scores, and laboratory variables (sodium and eosinophils). The levels of autoantibodies or immunoglobulins were reserved for the diagnosis of non-common disease. Conclusion: Our research confirms that some predictors are specific for the aetiological diagnosis of BE. The possibility of integrating this information may represent a useful tool for the diagnosis. The execution of certain specific tests should be reserved for patients with a non-common disease

Association between physical activity and risk of hospitalisation in bronchiectasis

Background: Patients with bronchiectasis have a less active lifestyle than healthy peers, but the association with hospital admission has not been explored. The aim of this study was to investigate the association between 1) any physical activity variable; and 2) sedentary time, with hospitalisation due to exacerbation in adults with bronchiectasis. Methods: In this prospective observational study, baseline lung function, quality of life, exercise tolerance, severity of bronchiectasis and physical activity were recorded. Physical activity was objectively assessed over a week using a SenseWear armband and the results were expressed in steps·day-1 and sedentary time. Number of hospitalisations due to a bronchiectasis exacerbation and time to first event were recorded after 1-year follow-up. Results: Sixty-four patients with bronchiectasis were analysed, of whom 15 (23%) were hospitalised during the follow-up. Hospitalised patients showed poor baseline clinical and severity outcomes, fewer steps walked per day and more sedentary behaviour than the non-hospitalised group. Patients who walked ≤6290 steps·day-1 or spent ≥7.8 h·day-1 in sedentary behaviour had an increased risk of hospital admission due to bronchiectasis exacerbation at 1-year follow-up. Specifically, ≥7.8 h·day-1 of sedentary behaviour was associated with a 5.9-fold higher risk of hospital admission in the following year. Conclusions: Low levels of physical activity and high sedentary time at baseline were associated with a higher risk of hospitalisation due to bronchiectasis exacerbation. If these findings are validated in future studies, it might be appropriate to include physical activity and sedentary behaviour as an item in severity scores

Mucoid Pseudomonas aeruginosa alters sputum viscoelasticity in patients with non-cystic fibrosis bronchiectasis

Introduction and aim: Pseudomonas aeruginosa could acquire a mucoid phenotype due to mutations in mucA (mucoid Pseudomonas aeruginosa - mPA) that is a hallmark of poor prognosis in patients with bronchiectasis. Despite the higher prevalence of Pseudomonas aeruginosa in bronchiectasis, how mPA and non-mucoid Pseudomonas aeruginosa (non-mPA) phenotypes could affect viscoelastic properties of sputum is unknown. Our aim was to determine the relationship between Pseudomonas aeruginosa phenotypes isolation, the viscoelastic properties of sputum and the clinical outcomes in patients with bronchiectasis. Methods: A cross-sectional study was conducted of sputum samples obtained by spontaneous expectoration and sent for microbiology and rheology analysis. Elasticity and viscosity were measured at two oscillatory frequencies (1 and 100 rad/s). Socio-demographic and clinical data were recorded. Results: We analyzed 17 patients with mPA, 14 with non-mPA and 17 with no organism reported (NOR). Compared with the NOR group, the mPA group showed higher elasticity (median 10.30 vs. 5.70, p = 0.023), viscosity (2.40 vs. 1.50, p = 0.039), and stiffness (10.70 vs. 6.00, p = 0.024). Values in the mPA group tended to be higher compared with non-mPA. Clinically, the mPA group showed greater hospitalizations during the previous year and greater affected lobes than the non-mPA and NOR groups. Conclusions: The mPA phenotype is associated with increased elasticity, viscosity and stiffness of bronchiectatic sputum. Viscoelastic properties could be used as a marker of poor mucociliary clearance in mPA, with potentially important clinical implications

Short-term effects of appropriate empirical antimicrobial treatment with Ceftolozane/Tazobactam in a swine model of nosocomial Pneumonia

The rising frequency of MDR/XDR pathogens is making more frequent the inappropriate empirical antimicrobial therapy (IEAT) in nosocomial pneumonia, which is associated with increased mortality. We aim to determine the short-term benefits of appropriate empirical antimicrobial treatment (AEAT) with C/T compared with IEAT with piperacillin/tazobactam(TZP) in MDR Pseudomonas aeruginosa (PA) pneumonia. Twenty-one pigs with pneumonia caused by XDR PA strain (susceptible to C/T but resistant to TZP) were ventilated up to 72h. Twenty-four hours after bacterial challenge, animals were randomized to receive 2-day treatment with either intravenous saline (untreated) or 50-25 mg/kg of C/T (AEAT) or 200-25 mg/kg of TZP (IEAT), every 8h. The primary outcome was the PA burden in lung tissue and the histopathology injury. PA burden in tracheal secretions and bronchoalveolar lavage (BAL) fluid, the development of antibiotic resistance and inflammatory markers were secondary outcomes. Overall PA lung burden was 5.30[4.00-6.30], 4.04[3.64-4.51], and 4.04[3.05-4.88] log10CFU/g in the untreated, AEAT and IEAT groups, respectively(p=0.299), without histopathological differences (p=0.556). In contrast, in tracheal secretions (p<0.001) and BAL fluid(p=0.002), bactericidal efficacy was higher in AEAT group. Increased minimum inhibitory concentration to TZP was found in 3 animals, while resistance to C/T did not develop. IL-1\u3b2 was significantly downregulated by AEAT, in comparison to other groups(p=0.031). In a mechanically ventilated swine model of XDR P. aeruginosa pneumonia, appropriate initial treatment with C/T decreased respiratory secretions' bacterial burden, prevented development of resistance, achieved pharmacodynamic target and may reduce systemic inflammation. Yet, after only 2 days of treatment, P. aeruginosa tissue concentrations were moderately affected