Diego Castillo

Diagnostic yield of transbronchial cryobiopsy in interstitial lung disease: A randomized trial

Transbronchial lung biopsy (TBLB) is required for evaluation in selected patients with interstitial lung disease (ILD). The diagnostic yield of histopathologic assessment is variable and is influenced by factors such as the size of samples and the presence of crush artefacts left by conventional biopsy forceps. We compared the diagnostic yield and safety of TBLB with cryoprobe sampling versus conventional forceps sampling.

In vivo electrical bioimpedance characterization of human lung tissue during the bronchoscopy procedure. A feasibility study

Lung biopsies form the basis for the diagnosis of lung cancer. However, in a significant number of cases bronchoscopic lung biopsies fail to provide useful information, especially in diffuse lung disease, so more aggressive procedures are required. Success could be improved using a guided electronic biopsy based on multisine electrical impedance spectroscopy (EIS), a technique which is evaluated in this paper. The theoretical basis of the measurement method and the instrument developed are described, characterized and calibrated while the performance of the instrument is assessed by experiments to evaluate the noise and nonlinear source of errors from measurements on phantoms. Additional preliminary results are included to demonstrate that it is both feasible and safe to monitor in vivo human lung tissue electrical bioimpedance (EBI) during the bronchoscopy procedure. The time required for performing bronchoscopy is not extended because the bioimpedance measurements, present no complications, tolerance problems or side effects among any of the patients measured.

Identification of airway bacterial colonization by an electronic nose in Chronic Obstructive Pulmonary Disease

BACKGROUND Airway bacterial colonization by potentially pathogenic microorganisms occurs in a proportion of patients with Chronic Obstructive Pulmonary Disease (COPD). It increases airway inflammation and influences outcomes negatively. Yet, its diagnosis in clinical practice is not straightforward. The electronic nose is a new non-invasive technology capable of distinguishing volatile organic compound (VOC) breath-prints in exhaled breath. We aim to explore if an electronic nose can reliably discriminate COPD patients with and without airway bacterial colonization. METHODS We studied 37 clinically stable COPD patients (67.8 ± 5.2 yrs, FEV1 41 ± 10% ref.) and 13 healthy controls (62.8 ± 5.2 yrs, FEV1 99 ± 10% ref.). The presence of potentially pathogenic microorganisms in the airways of COPD patients (n = 10, 27%) was determined using quantitative bacterial cultures of protected specimen brush. VOCs breath-prints were analyzed by discriminant analysis on principal component reduction, resulting in cross-validated accuracy values. Area Under Receiver Operating Characteristics (AUROC) was calculated using multiple logistic regression. RESULTS Demographic, functional and clinical characteristics were similar in colonized and non-colonized COPD patients but their VOC breath-prints were different (accuracy 89%, AUROC 0.92, p > 0.0001). Likewise, VOCs breath-prints from colonized (accuracy 88%, AUROC 0.98, p < 0.0001) and non-colonized COPD patients (accuracy 83%, AUROC 0.93, p < 0.0001) were also different from controls. CONCLUSIONS An electronic nose can identify the presence of airway bacterial colonization in clinically stable patients with COPD.

Secreted mucins and airway bacterial colonization in non-CF bronchiectasis

Secreted mucins play a key role in antibacterial defence in the airway, but have not previously been characterized in non‐cystic fibrosis (CF) bronchiectasis patients. We aim to investigate the relationship between secreted mucins levels and the presence of bacterial colonization due to potentially pathogenic microorganisms (PPM) in the airways of stable bronchiectasis patients.

Sistemas de ahorro de oxígeno. Una realidad olvidada

Los sistemas de ahorro de oxigeno agrupan el cateter transtraqueal, las canulas reservorio y los sistemas a demanda. Su objetivo es aumentar la autonomia de las fuentes de oxigeno portatiles consiguiendo una correccion de la hi-poxemia con menor flujo de oxigeno. El cateter transtraqueal aumenta la fraccion inspiratoria de oxigeno al proporcionar oxigeno directamente en la traquea, lo que evita el espacio muerto de la cavidad orofaringea y favorece que la via aerea superior actue como reservorio. Las canulas reservorio aumentan la fraccion inspiratoria de oxigeno al inicio de la inspiracion. Los sistemas a demanda cuentan con una valvula que se activa con la inspiracion, de modo que se administra oxigeno solo durante esta fase del ciclo respiratorio. Debido a sus diferentes caracteristicas, cada sistema presenta ventajas e inconvenientes. Para su correcta prescripcion debe ajustarse individualmente el flujo de oxigeno tanto en reposo como durante el ejercicio o el sueno con las pruebas pertinentes.

Pseudomonas aeruginosa resistance patterns and clinical outcomes in hospitalized exacerbations of COPD

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) due to Pseudomonas aeruginosa (PA) are associated with worse outcomes. PA antibiotic resistance is important to determine treatment and may influence clinical outcomes. The aim was to study clinical characteristics and outcomes in patients with AECOPD associated with PA based on their antibiotic resistance.

Normativa sobre el tratamiento farmacológico de la fibrosis pulmonar idiopática

Idiopathic pulmonary fibrosis is defined as chronic fibrosing interstitial pneumonia limited to the lung, with poor prognosis. The incidence has been rising in recent years probably due to improved diagnostic methods and increased life expectancy. In 2013, the SEPAR guidelines for the diagnosis and treatment for idiopathic pulmonary fibrosis were published. Since then, clinical trials and meta-analyses have shown strong scientific evidence for the use of pirfenidone and nintedanib in the treatment of idiopathic pulmonary fibrosis. In 2015, the international consensus of 2011 was updated and new therapeutic recommendations were established, prompting us to update our recommendation for the medical treatment of idiopathic pulmonary fibrosis accordingly. Diagnostic aspects and non-pharmacological treatment will not be discussed as no relevant developments have emerged since the 2013 guidelines.

Airway Mucin 2 Is Decreased in Patients with Severe Chronic Obstructive Pulmonary Disease with Bacterial Colonization

RATIONALE Mucins are essential for airway defense against bacteria. We hypothesized that abnormal secreted airway mucin levels would be associated with bacterial colonization in patients with severe chronic obstructive pulmonary disease (COPD) Objectives: To investigate the relationship between mucin levels and the presence of potentially pathogenic micro-organisms in the airways of stable patients with severe COPD Methods: Clinically stable patients with severe COPD were examined prospectively. All patients underwent a computerized tomography scan, lung function tests, induced sputum collection, and bronchoscopy with bronchoalveolar lavage (BAL) and protected specimen brush. Patients with bronchiectasis were excluded. Secreted mucins (MUC2, MUC5AC, and MUC5B) and inflammatory markers were assessed in BAL and sputum by ELISA. MEASUREMENTS AND MAIN RESULTS We enrolled 45 patients, with mean age (±SD) of 67 (±8) years and mean FEV1 of 41 (±10) % predicted. A total of 31% (n = 14) of patients had potentially pathogenic micro-organisms in quantitative bacterial cultures of samples obtained by protected specimen brush. Patients with COPD with positive cultures had lower levels of MUC2 both in BAL (P = 0.02) and in sputum (P = 0.01). No differences in MUC5B or MUC5AC levels were observed among the groups. Lower MUC2 levels were correlated with lower FEV1 (r = 0.32, P = 0.04) and higher sputum IL-6 (r = -0.40, P = 0.01). CONCLUSIONS Airway MUC2 levels are decreased in patients with severe COPD colonized by potentially pathogenic micro-organisms. These findings may indicate one of the mechanisms underlying airway colonization in patients with severe COPD. Clinical trial registered with www.clinicaltrials.gov (NCT01976117).

Monóxido de carbono: dos caras de un mismo personaje

El monóxido de carbono (CO) es el fruto de la combustión incompleta de la materia orgánica. Cuando los constituyentes carbonados se queman en presencia de suficiente cantidad de oxígeno, el producto final es el dióxido de carbono y el agua. Cuando esta reacción química tiene lugar en condiciones precarias de oxígeno, el producto final es el CO. En otro contexto, la sangre, y en particular la hemoglobina, es la molécula especializada para el transporte de oxígeno desde el lugar de carga (los pulmones) hasta su consumo celular (todas las mitocondrias). Hemoglobina y oxígeno forman la oxihemoglobina, y su unión es un ejemplo de elegancia, armonía e incluso de belleza. Como decía un viejo profesor de fisiología, “en la molécula de hemoglobina puede observarse la poesía de la creación”. Pero la hemoglobina se une a otros elementos y con otro tipo de enlaces. Cuando se una al CO, forma la denominada carboxihemoglobina, una molécula que forma parte de las denominadas dishemoglobinas junto a la sulfahemoglobina y la metahemoglobina. Su concentración habitual se halla entre el 1 y el 2% del total de la hemoglobina en sangre y procede fundamentalmente de una producción endógena. Se calcula que se producen 0,4 ml/h de CO. Esta producción endógena, según se demostró en el estudio clásico de Sjostrand1, procede mayoritariamente del catabolismo de las proteínas del grupo hem2. Éste se encuentra sobre todo en la hemoglobina y, en menor cuantía, en la mioglobina y en los citocromos. Mediante la enzima hemoxigenasa (tanto en su forma inducible como constitutiva), el grupo hem se transforma en biliverdina, hierro y CO, de forma equitativa. La primera se transforma en bilirrubina, el segundo se recicla y el tercero, dada su gran afinidad, se une a la hemoglobina para formar la carboxihemoglobina. Las anemias hemolíticas son la principal causa de aumento de carboxihemoglobina de origen endógeno3, aunque también se aprecia un ligero aumento en enfermedades inflamatorias graves. Lógicamente, existe también una fuente externa de producción de CO. El componente exógeno de CO en la sangre es secundario a su inhalación. El CO ambiental es fundamentalmente fruto de la contaminación de las grandes ciudades (coches y calefacciones), aunque no es desdeñable la participación de los quemadores de gas en malas condiciones en el interior de los domicilios. Normalmente se encuentra en un valor inferior a 10 ppm. Su producción está aumentada de forma crónica en los fumadores (hasta 400-500 ppm en el aire inhalado mientras fumamos) y de forma aguda en intoxicaciones, principalmente por intento de autólisis. Se estima que el CO puede ser responsable de más de la mitad de las intoxicaciones letales en todo el mundo4. El monóxido de carbono, dada su alta afinidad por la hemoglobina (200-250 veces mayor que la del oxígeno), puede reducir de manera drástica la capacidad de transportar oxígeno, lo cual puede repercutir gravemente en la salud. Los síntomas secundarios a su toxicidad varían desde simples mareos o dolores de cabeza hasta la muerte.

Oxygen-Conserving Systems: A Forgotten Resource

Oxygen-conserving devices include transtracheal catheters, reservoir cannulas, and demand oxygen delivery systems. They are designed to extend the amount of time portable oxygen cylinders will last and correct hypoxemia with a lower flow of oxygen. Transtracheal catheters increase the fraction of inspired oxygen by delivering oxygen directly to the trachea, bypassing the dead space of the oropharynx and improving the efficiency of the upper airway as a reservoir. Reservoir cannulas increase the fraction of inspired oxygen at the beginning of the inspiratory phase. Demand oxygen delivery systems have a valve that is activated during inspiration, meaning that oxygen is only delivered during this stage of the respiratory cycle. Each system has advantages and disadvantages arising from differing design features. Prescription should be based on individual tests in all cases to ensure optimal oxygen delivery during rest, exercise, and sleep.