Microorganisms, particularly bacteria, are frequently found in the lower airways of COPD patients, both in stable state and during exacerbations. The host-pathogen relationship in COPD is a complex, dynamic process characterised by frequent changes in pathogens, their strains and loads, and subsequent host immune responses. Exacerbations are detrimental events in the course of COPD and evidence suggests that 70% may be caused by microorganisms. When considering bacterial exacerbations, recent findings based on molecular typing have demonstrated that the acquisition of new strains of bacteria or antigenic changes in pre-existing strains are the most important triggers for exacerbation onset. Even in clinically stable COPD patients the presence of microorganisms in their lower airways may cause harmful effects and induce chronic low-grade airway inflammation leading to increased exacerbation frequency, an accelerated decline in lung function and impaired health-related quality of life. Besides intraluminal localisation in the distal airways, bacteria can be found in the bronchial walls and parenchymal lung tissue of COPD patients. Therefore, the isolation of pathogenic bacteria in stable COPD should be considered as a form of chronic infection rather than colonisation. This new approach may have important implications for the management of patients with COPD.

Background: It is crucial to identify risk factors for poor evolution of patients admitted to hospital with chronic obstructive pulmonary disease (COPD) in order to provide adequate intensive therapy and closer follow-up. Objectives: To identify predictors of adverse outcomes in patients hospitalised for exacerbation of COPD. Methods: A prospective, observational study was conducted in patients admitted for exacerbation of COPD. Demographic and clinical parameters were evaluated, including different multidimensional prognostic scores. Adverse outcomes included the following: death during hospitalisation or 1-month follow-up, intensive care unit admission, invasive or non-invasive mechanical ventilation, prolonged hospitalisation (>11 days) and COPD-related emergency visit or readmission within 1 month after discharge. Univariate and multivariate analysis were performed. Results: Of 155 patients included, an adverse outcome occurred in 69 (45%). Patients with an adverse outcome had lower forced expiratory volume in 1 s (p = 0.004) and more frequent exacerbations (p = 0.011), more frequently used oxygen at home (p = 0.042) and presented with lower pH (p < 0.001), lower ratio of arterial oxygen pressure to the fraction of inspired oxygen (p = 0.006), higher arterial carbon dioxide pressure (p < 0.001) and a worse score on several prognostic indices at admission. Independent predictors of adverse outcome were exacerbation of COPD in the previous year [odds ratio 3.9, 95% confidence interval (CI) 1.6–9.9; p = 0.004], hypercapnia (odds ratio 9.4, 95% CI 3.7–23.6; p < 0.001) and hypoxaemia (odds ratio 4.3, 95% CI 1.5–12.6; p = 0.008). In the presence of all three characteristics, the probability of an adverse outcome was 95%, while hypercapnia was the strongest prognostic factor with a risk of 54%. Conclusions: Patients with previous exacerbation of COPD, hypercapnia and hypoxaemia had the highest risk of an unfavourable evolution. The calculation of prognostic indices did not provide additional discriminative power.

The study was designed to investigate efficacy and safety of Astragalus membranaceus (AM) in the treatment of patients with seasonal allergic rhinitis (SAR). AM is an active component in the herbal and mineral complex (HMC) registered in Croatia as a food supplement Lectranal. The study was designed as a 6-weeks, double-blind, placebo-controlled clinical trial and conducted in 48 adult patients with a moderate to severe SAR. The treatment efficacy was evaluated by the mean change in the symptom score (TSS), quality of life (QoL), specific serum IgE and IgG, nasal eosinophils, and physicians' and patients' global evaluation. Compared to placebo, HMC significantly decreased the intensity of rhinorrhea while for other primary efficacy variables the treatment groups did not differ. In contrast, investigators and patients equally judged the treatment with HMC as more efficacious. In addition, the analysis of changes from baseline inside the groups for TSS, QoL, and 4 main symptoms of SAR were strikingly in favor of the active treatment. In patients with SAR due to weed pollen allergy HMC significantly improved primary variables, reflective TSS and QoL. The study revealed a significant number of positive signals indicating the therapeutic effectiveness of the HMC in patients with SAR which should be further tested in larger, multicentre trials with more patients.