Measurement driven quantum evolution

We study the problem of mapping an unknown mixed quantum state onto a known pure state without the use of unitary transformations. This is achieved with the help of sequential measurements of two non-commuting observables only. We show that the overall success probability is maximized in the case of measuring two observables whose eigenstates define mutually unbiased bases. We find that for this optimal case the success probability quickly converges to unity as the number of measurement processes increases and that it is almost independent of the initial state. In particular, we show that to guarantee a success probability close to one the number of consecutive measurements must be larger than the dimension of the Hilbert space. We connect these results to quantum copying, quantum deleting and entanglement generation.Comment: 7 pages, 1 figur

Factors associated with change in exacerbation frequency in COPD

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) can be categorized as having frequent (FE) or infrequent (IE) exacerbations depending on whether they respectively experience two or more, or one or zero exacerbations per year. Although most patients do not change category from year to year, some will, and the factors associated with this behaviour have not been examined. METHODS: 1832 patients completing two year follow-up in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) study were examined at baseline and then yearly. Exacerbations were defined by health care utilisation. Patient characteristics compared between those patients who did or did not change exacerbation category from year 1 to year 2. FINDINGS: Between years 1 and 2, 221 patients (17%) changed from IE to FE and 210 patients (39%) from FE to IE. More severe disease was associated with changing from IE to FE and less severe disease from FE to IE. Over the preceding year, small falls in FEV(1) and 6-minute walking distance were associated with changing from IE to FE, and small falls in platelet count associated with changing from FE to IE. CONCLUSION: No parameter clearly predicts an imminent change in exacerbation frequency category. TRIAL REGISTRATION: SCO104960, clinicaltrials.gov identifier NCT0029255

Association Between Ventilatory Settings and Development of Acute Respiratory Distress Syndrome in Mechanically Ventilated Patients Due to Brain Injury

PURPOSE: In neurologically critically ill patients with mechanical ventilation (MV), the development of acute respiratory distress syndrome (ARDS) is a major contributor to morbidity and mortality, but the role of ventilatory management has been scarcely evaluated. We evaluate the association of tidal volume, level of PEEP and driving pressure with the development of ARDS in a population of patients with brain injury. MATERIALS AND METHODS: We performed a secondary analysis of a prospective, observational study on mechanical ventilation. RESULTS: We included 986 patients mechanically ventilated due to an acute brain injury (hemorrhagic stroke, ischemic stroke or brain trauma). Incidence of ARDS in this cohort was 3%. Multivariate analysis suggested that driving pressure could be associated with the development of ARDS (odds ratio for unit increment of driving pressure 1.12; confidence interval for 95%: 1.01 to 1.23) whereas we did not observe association for tidal volume (in ml per kg of predicted body weight) or level of PEEP. ARDS was associated with an increase in mortality, longer duration of mechanical ventilation, and longer ICU length of stay. CONCLUSIONS: In a cohort of brain-injured patients the development of ARDS was not common. Driving pressure was associated with the development of this disease.info:eu-repo/semantics/publishedVersio

Glycopyrrolate/formoterol fumarate metered dose inhaler for maintenance-naïve patients with chronic obstructive pulmonary disease:a post-hoc analysis of the randomized PINNACLE trials

Background: Glycopyrrolate (GP)/formoterol fumarate (FF; GFF) metered dose inhaler is a fixed-dose combination dual bronchodilator for patients with chronic obstructive pulmonary disease (COPD); however, whether the efficacy in patients without current maintenance treatment is consistent with currently maintenance-treated patients is unclear.Methods: Data from patients who were not maintenance-treated at screening (NMT) (n = 1943) and patients who were maintenance-treated at screening (MT) patients (n = 3040) receiving GFF, FF, GP, or placebo were pooled from the Phase III PINNACLE studies (NCT01854645, NCT01854658, NCT02343458) for post-hoc analysis. MT patients had received long-acting bronchodilators and/or inhaled corticosteroids in the 30 days prior to screening, and/or prior to randomization. NMT patients had received short-acting bronchodilators or no treatment. Outcomes included forced expiratory volume over 1 s (FEV1), clinically important deterioration (CID), rescue medication use, and safety.Results: GFF provided significant lung function improvements at Week 24 versus placebo, GP, and FF for NMT patients, with pre-dose trough FEV1 treatment differences of 152 (117-188) mL, 73 (45-100) mL, and 56 (29-84) mL, respectively (least squares mean change from baseline versus comparators [95% CI]; all P &lt; 0.0001). GFF reduced the risk of CID by 17-43% in NMT (P ≤ 0.0157) and 18-52% (P ≤ 0.0012) in MT patients compared with monotherapy and placebo, and reduced rescue medication use by 1.5 puffs/day over 24 weeks for both cohorts. Safety profiles for all cohorts were consistent with each other and the parent studies.Conclusions: NMT patients achieved better lung function with GFF versus monotherapy and placebo, without increased safety risk. Dual bronchodilator therapy may offer better outcomes than monotherapy for COPD patients when administered as first-line treatment.</p

Risk factors for exacerbations and pneumonia in patients with chronic obstructive pulmonary disease: a pooled analysis.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) are at risk of exacerbations and pneumonia; how the risk factors interact is unclear. METHODS: This post-hoc, pooled analysis included studies of COPD patients treated with inhaled corticosteroid (ICS)/long-acting β2 agonist (LABA) combinations and comparator arms of ICS, LABA, and/or placebo. Backward elimination via Cox's proportional hazards regression modelling evaluated which combination of risk factors best predicts time to first (a) pneumonia, and (b) moderate/severe COPD exacerbation. RESULTS: Five studies contributed: NCT01009463, NCT01017952, NCT00144911, NCT00115492, and NCT00268216. Low body mass index (BMI), exacerbation history, worsening lung function (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage), and ICS treatment were identified as factors increasing pneumonia risk. BMI was the only pneumonia risk factor influenced by ICS treatment, with ICS further increasing risk for those with BMI <25 kg/m2. The modelled probability of pneumonia varied between 3 and 12% during the first year. Higher exacerbation risk was associated with a history of exacerbations, poorer lung function (GOLD stage), female sex and absence of ICS treatment. The influence of the other exacerbation risk factors was not modified by ICS treatment. Modelled probabilities of an exacerbation varied between 31 and 82% during the first year. CONCLUSIONS: The probability of an exacerbation was considerably higher than for pneumonia. ICS reduced exacerbations but did not influence the effect of risks associated with prior exacerbation history, GOLD stage, or female sex. The only identified risk factor for ICS-induced pneumonia was BMI <25 kg/m2. Analyses of this type may help the development of COPD risk equations

Severe Pneumococcal Pneumonia Causes Acute Cardiac Toxicity and Subsequent Cardiac Remodeling

Rationale: Up to one-third of patients hospitalized with pneumococcal pneumonia experience major adverse cardiac events (MACE) during or after pneumonia. In mice, Streptococcus pneumoniae caninvade themyocardium, induce cardiomyocyte death, and disrupt cardiac function following bacteremia, but it is unknown whether the same occurs in humans with severe pneumonia. Objectives: We sought to determine whether S. pneumoniae can (1) translocate the heart, (2) induce cardiomyocyte death, (3) causeMACE, and (4) induce cardiac scar formation after antibiotic treatment during severe pneumonia using a nonhuman primate (NHP) model. Methods: We examined cardiac tissue from six adult NHPs with severe pneumococcal pneumonia and three uninfected control animals. Three animals were rescued with antibiotics (convalescent animals). Electrocardiographic, echocardiographic, and serum biomarkers of cardiac damage were measured (troponin T, N-terminal pro-brain natriuretic peptide, and heart-type fatty acid binding protein). Histological examination included hematoxylin and eosin staining, immunofluorescence, immunohistochemistry, picrosirius red staining, and transmission electron microscopy. Immunoblots were used to assess the underlying mechanisms. Measurements and Main Results: Nonspecific ischemic alterations were detected by electrocardiography and echocardiography. Serum levels of troponin T and heart-type fatty acid binding protein were increased (P,0.05) after pneumococcal infection in both acutely ill and convalescent NHPs. S. pneumoniae was detected in the myocardium of all NHPs with acute severe pneumonia. Necroptosis and apoptosis were detected in the myocardium of both acutely ill and convalescent NHPs. Evidence of cardiac scar formation was observed only in convalescent animals by transmission electron microscopy and picrosirius red staining. Conclusions: S. pneumoniae invades the myocardium and induces cardiac injury with necroptosis and apoptosis, followed by cardiac scarring after antibiotic therapy, in anNHP model of severe pneumonia

Severe Hypercapnia and Outcome of Mechanically Ventilated Patients with Moderate or Severe Acute Respiratory Distress Syndrome

PURPOSE: To analyze the relationship between hypercapnia developing within the first 48 h after the start of mechanical ventilation and outcome in patients with acute respiratory distress syndrome (ARDS). PATIENTS AND METHODS: We performed a secondary analysis of three prospective non-interventional cohort studies focusing on ARDS patients from 927 intensive care units (ICUs) in 40 countries. These patients received mechanical ventilation for more than 12 h during 1-month periods in 1998, 2004, and 2010. We used multivariable logistic regression and a propensity score analysis to examine the association between hypercapnia and ICU mortality. MAIN OUTCOMES: We included 1899 patients with ARDS in this study. The relationship between maximum PaCO2 in the first 48 h and mortality suggests higher mortality at or above PaCO2 of ≥50 mmHg. Patients with severe hypercapnia (PaCO2 ≥50 mmHg) had higher complication rates, more organ failures, and worse outcomes. After adjusting for age, SAPS II score, respiratory rate, positive end-expiratory pressure, PaO2/FiO2 ratio, driving pressure, pressure/volume limitation strategy (PLS), corrected minute ventilation, and presence of acidosis, severe hypercapnia was associated with increased risk of ICU mortality [odds ratio (OR) 1.93, 95% confidence interval (CI) 1.32 to 2.81; p = 0.001]. In patients with severe hypercapnia matched for all other variables, ventilation with PLS was associated with higher ICU mortality (OR 1.58, CI 95% 1.04-2.41; p = 0.032). CONCLUSIONS: Severe hypercapnia appears to be independently associated with higher ICU mortality in patients with ARDS.info:eu-repo/semantics/publishedVersio

Impact of prior outpatient antibiotic use on mortality for community acquired pneumonia: a retrospective cohort study

Abstract Background The purpose of this study was to examine whether prior outpatient antibiotic use is associated with increased 30-day mortality, after adjusting for potential confounders, for those subsequently hospitalized with pneumonia. Methods A retrospective cohort study conducted at two tertiary teaching hospitals. Eligible subjects were admitted with a diagnosis of, and had a chest x-ray consistent with, community-acquired pneumonia. Our primary analysis was a multivariable logistic regression with the dependent variable of 30-day mortality. Results Data was abstracted on 733 subjects at the two hospitals. Mortality was 8.1% at 30-days. At presentation, 55% of subjects were low risk, 33% were moderate risk, and 12% were high risk. In our cohort 17% (n = 128) of subjects received antibiotics within 30-days of presentation. Unadjusted mortality for those who had received prior antibiotics was 7.0% vs. 8.3% for those who had not (p = 0.6). In the multivariable analysis prior use of antibiotics (odds ratio 0.98, 95% confidence interval 0.5–2.1) was not significantly associated with 30-day mortality. Conclusion Receipt of prior outpatient antibiotics is not significantly associated with 30-day mortality for patients hospitalized with pneumonia. Our study supports current efforts to increase the number of patients with pneumonia who are treated as outpatients.</p