Anna Maria Brambilla

Stratifying Risk Factors for Multidrug-Resistant Pathogens in Hospitalized Patients Coming From the Community With Pneumonia

BACKGROUND  Not all risk factors for acquiring multidrug-resistant (MDR) organisms are equivalent in predicting pneumonia caused by resistant pathogens in the community. We evaluated risk factors for acquiring MDR bacteria in patients coming from the community who were hospitalized with pneumonia. Our evaluation was based on actual infection with a resistant pathogen and clinical outcome during hospitalization. METHODS  An observational, prospective study was conducted on consecutive patients coming from the community who were hospitalized with pneumonia. Data on admission and during hospitalization were collected. Logistic regression models were used to evaluate risk factors for acquiring MDR bacteria independently associated with the actual presence of a resistant pathogen and in-hospital mortality. RESULTS  Among the 935 patients enrolled in the study, 473 (51%) had at least 1 risk factor for acquiring MDR bacteria on admission. Of all risk factors, hospitalization in the preceding 90 days (odds ratio [OR], 4.87 95% confidence interval {CI}, 1.90-12.4]; P = .001) and residency in a nursing home (OR, 3.55 [95% CI, 1.12-11.24]; P = .031) were independent predictors for an actual infection with a resistant pathogen. A score able to predict pneumonia caused by a resistant pathogen was computed, including comorbidities and risk factors for MDR. Hospitalization in the preceding 90 days and residency in a nursing home were also independent predictors for in-hospital mortality. CONCLUSIONS  Risk factors for acquiring MDR bacteria should be weighted differently, and a probabilistic approach to identifying resistant pathogens among patients coming from the community with pneumonia should be embraced.

Rapid Diagnosis of Mycobacterial Infections and Quantitation of Mycobacterium tuberculosis Load by Two Real-Time Calibrated PCR Assays

ABSTRACT Sensitive and specific techniques to detect and identify Mycobacterium tuberculosis directly in clinical specimens are important for the diagnosis and management of patients with tuberculosis (TB). We developed two real-time PCR assays, based on the IS6110 multicopy element and on the senX3-regX3 intergenic region, which provide a rapid method for the diagnosis of mycobacterial infections. The sensitivity and specificity of both assays were established by using purified DNA from 71 clinical isolates and 121 clinical samples collected from 83 patients, 20 of whom were affected by TB. Both assays are accurate, sensitive, and specific, showing a complementary pattern of Mycobacterium recognition: broader for the IS6110-based assay and restricted to the M. tuberculosis complex for the senX3-regX3-based assay. Moreover, the addition of a synthetic DNA calibrator prior to DNA extraction allowed us to measure the efficiency of DNA recovery and to control for the presence of PCR inhibitors. The mycobacterial burden of the clinical samples, as assessed by direct microscopy, correlates with the M. tuberculosis DNA load measured by the senX3-regX3-based assay. In addition, reduced levels of M. tuberculosis DNA load are present in those patients subjected to successful therapy, suggesting a potential use of this assay for monitoring treatment efficacy. Therefore, these assays represent a fully controlled high-throughput system for the evaluation of mycobacterial burden in clinical specimens.

Severe asthma exacerbation: role of acute Chlamydophila pneumoniae and Mycoplasma pneumoniae infection

BackgroundChlamydophila pneumoniae and Mycoplasma pneumoniae are associated with acute exacerbation of bronchial asthma (AEBA). The aim of this study was to evaluate the correlation between these acute bacterial infections and the severity of AEBA.MethodsWe prospectively analysed consecutive patients admitted to the Emergency Department with acute asthma exacerbation. In every patient peak expiratory flow (PEF) measurement was performed on admission, and spirometry during follow-up. Serology for Chlamydophila and Mycoplasma pneumoniae was performed on admission and after 4–8 weeks.ResultsFifty-eight patients completed the study. Acute atypical infections (AAI) was observed in 22/58 cases; we found single acute C. pneumoniae in 19 cases, single acute M. pneumoniae in 2 cases, and double acute infection in one case. Functional impairment on admission was greater in patients with AAI than in patients without AAI (PEF 205 ± 104 L/min vs 276 ± 117 p = 0.02) and persisted until visit 2 (FEV1% 76.30 ± 24.54 vs FEV1% 92.91 ± 13.89, p = 0.002). Moreover, the proportion of patients who presented with severe AEBA was significantly greater in the group with AAI than in the group without AAI (15/22 vs 12/36, p = 0.01; OR 4.29, 95% CI 1.38–13.32).ConclusionOur data suggest an association between acute atypical infection and a more severe AEBA.

Helmet Continuous Positive Airway Pressure vs Oxygen Therapy To Improve Oxygenation in Community-Acquired Pneumonia A Randomized, Controlled Trial

OBJECTIVE Our objective was to evaluate the efficacy of noninvasive continuous positive airway pressure (CPAP) delivered by helmet in improving oxygenation in comparison with oxygen therapy in community-acquired pneumonia (CAP). METHODS This was a multicenter, randomized, controlled trial enrolling patients with CAP admitted to an ED with moderate hypoxemic acute respiratory failure (ARF) (Pa(O(2))/Fi(O(2)) ratio > or = 210 and < or = 285). Patients were randomized to helmet CPAP or standard oxygen therapy (control group). The primary end point was the time to reach a Pa(O(2))/Fi(O(2)) ratio > 315. After reaching this value, patients randomized to CPAP were switched to oxygen, and the proportion of subjects who could maintain a Pa(O(2))/Fi(O(2)) ratio > 315 at 1 h was recorded. RESULTS Forty-seven patients were recruited: 20 randomized to CPAP and 27 to controls. Patients randomized to CPAP reached the end point in a median of 1.5 h, whereas controls reached the end point in 48 h (P < .001). The proportion of patients who reached the primary end point was 95% (19/20) among the CPAP group and 30% (8/27) among controls (P < .001). One hour after reaching the primary end point, 2/14 patients in the CPAP group maintained a Pa(O(2))/Fi(O(2)) value > 315. CONCLUSIONS CPAP delivered by helmet rapidly improves oxygenation in patients with CAP suffering from a moderate hypoxemic ARF. This trial represents a proof-of-concept evaluation of the potential usefulness of CPAP in patients with CAP.

Stavudine or indinavir-containing regimens are associated with an increased risk of diabetes mellitus in HIV-infected individuals

Diabetes mellitus was diagnosed in 16 out of 1011 HIV-positive patients over a median follow-up of 289 days (person-year incidence 2.06, 95% confidence interval 1.18-3.33). Significant risk factors for the onset of diabetes were older age and antiretroviral therapy with stavudine or indinavir. Older men with HIV infection should be considered at higher risk of diabetes, and caution maybe warranted in the use of both indinavir and stavudine in these patients.

The fate of triazine pesticides in River Po water

A group of triazine herbicides has been monitored in river Po water over a period of three years. The N-deethylated metabolite of atrazine was also found. Laboratory tests of biodcgradation of triazine performed with River Po water as cultural medium did not show any significant triazine degradation, leading to the conclusion that triazine metabolites derive from de.~-adation in soil. The chemical reactivity of triazines toward oxidants was also tested in laboratory with lead(IV) acetate, cerium(IV) ammonium nitrate and ozone. A chemical degradation pathway for triazines is suggested.

Low CURB-65 is of limited value in deciding discharge of patients with community-acquired pneumonia

BACKGROUND The relationship between clinical judgment and indications of the CURB-65 score in deciding the site-of-care for patients with community-acquired pneumonia (CAP) has not been fully investigated. The aim of this study was to evaluate reasons for hospitalization of CAP patients with CURB-65 score of 0 and 1. METHODS An observational, retrospective study of consecutive CAP patients was performed at the Fondazione Cà Granda, Milan, Italy, between January 2005 and December 2006. The medical records of hospitalized patients with CAP having a CURB-65 score of 0 and 1 were identified and reviewed to determine whether there existed a clinical basis to justify hospitalization. RESULTS Among the 580 patients included in the study, 218 were classified with a CURB-65 score of 0 or 1. Among those, 127 were hospitalized, and reasons that justified hospitalization were found in 104 (83%) patients. Main reasons for hospitalization included the presence of hypoxemia on admission (35%), failure of outpatient therapy (14%) and the presence of cardiovascular events on admission (9.7%). Used as the sole indicator for inappropriate hospitalization, the CURB-65 score had a poor positive predictive value of 52%. CONCLUSIONS Although the CURB-65 has been proposed as a tool to guide the site of care decision by international guidelines, this score is not ideal by itself, and should not be regarded as providing decision support information if a score of 0 and 1 is present. In CAP patients with CURB-65 scores of 0 or 1, further evaluations should be performed and completed by clinical judgment.

An improved in vivo rat model for the study of mechanical ventilatory support effects on organs distal to the lung

ObjectiveTo study the influence of different mechanical ventilatory support strategies on organs distal to the lung, we developed an in vivo rat model, in which the effects of different tidal volume values can be studied while maintaining other indexes. DesignProspective, randomized animal laboratory investigation. SettingUniversity laboratory of Ospedale Maggiore di Milano–Instituto di Ricovero e Cura a Carattere Scientifico. SubjectsAnesthetized, paralyzed, and mechanically ventilated male Sprague-Dawley rats. InterventionsTwo groups of seven rats each were randomized to receive tidal volumes of either 25% or 75% of inspiratory capacity (IC), calculated from a preliminary estimation of total lung capacity. Ventilation strategies for the two groups were as follows: a) 25% IC, 9.9 ± 0.8 mL/kg; frequency, 59 ± 4 beats/min; positive end-expiratory pressure, 3.6 ± 0.8 cm H2O; and peak inspiratory airway pressure (P aw), 13.2 ± 2 cm H2O; and b) 75% IC, 29.8 ± 2.9; frequency, 23 ± 13; positive end-expiratory pressure, 0; peak inspiratory P aw, 29.0 ± 3. Measurements and Main ResultsMean arterial pressure (invasively monitored) remained well above adequate perfusion pressure values throughout, and no significant difference was seen between the two groups. Pao2, pHa, and Paco2 values were compared after 60 mins of ventilation and again, no significant difference was seen between the two groups (Pao2, 269 ± 25 and 260 ± 55 torr; pHa, 7.432 ± 0.09 and 7.415 ± 0.03; Paco2, 35.4 ± 8 and 32.5 ± 2 torr, for the 25% IC and 75% IC groups, respectively). Mean Paws were not different (6.4 ± 0.8 cm H2O in the 25% IC groups, and 6.1 ± 1.2 in the 75% IC groups, respectively). At the end of the experiment, animals were killed and the liver and kidney isolated, fixed in 4% formalin, cut, and stained for optic microscopy. Kidneys from rats ventilated with 75% IC showed increased Bowman’s space with collapse of the glomerular capillaries. This occurred in a greater percentage of rats ventilated with 75% IC (0.67 ± 0.2 vs. 0.29 ± 0.2, 75% IC vs. 25% IC, respectively;p < .05). Perivascular edema was also present in rats ventilated with 75% IC (p < .05). Morphometric determinations of the empty zones (index of edema) demonstrated a trend toward differences between 75% IC livers and 25% IC (0.14 ± 0.05 vs. 0.11 ± 0.02, respectively). ConclusionWe conclude that it is possible to study the effects of mechanical ventilatory support on organs distal to the lung by means of an in vivo rat model.

Ozone oxidation of polyethoxylated alcohols

Abstract The ozonation of a polyethoxylated alcohol (typical of one type of detergent) mixture was performed in aqueous solution under different conditions of pH, reaction time and hydrogen peroxide addition. Surfactant degradation was monitored by TOC measurements. The optimal degradation conditions were found to be at pH = 7.5 with hydrogen peroxide addition. Inspection of the reaction products was carried out by GC-MS and GC-FTIR analysis of the silylated mixtures. The main oxidation products of ethoxylated alcohols are dicarboxylic acids.

Reactivity of two models of non-ionic surfactants with ozone

The ozonation of ethylene glycol and diethylene glycol mono-n-octylether (models of non-ionic surfactants) has been performed in aqueous solution at pH 4 and pH 9.5. The experiments at acidic pH show that the methylene groups adjacent to the ethereal oxygens are transformed into carbonyl groups. At alkaline pH the aliphatic chain is cleaved. Kinetic experiments allow to suggest a reaction mechanisms.