Early Lung Function Abnormalities in Acromegaly.

BACKGROUND: Acromegaly is an insidious disorder caused by a pituitary growth hormone (GH)-secreting adenoma resulting in high circulating levels of GH and insulin-like growth factor I (IGF-I). Respiratory disorders are common complications in acromegaly, and can severely impact on quality of life, eventually affecting mortality. OBJECTIVES: The present study aimed to explore structural and functional lung alterations of acromegalic subjects. METHODS: We enrolled 10 consecutive patients (M/F: 5/5) affected by acromegaly. In all patients, magnetic resonance imaging (MRI) revealed the presence of pituitary tumor. All patients underwent clinical, lung functional, biological, and radiological assessments. Ten healthy age-matched subjects also served as controls. RESULTS: No statistically significant differences in lung function were detected between acromegalic and healthy subjects (p ≥ 0.05 for all analyses). However, the diffusing capacity for CO (TLCO) was significantly lower in the acromegalic group than in healthy subjects (TLCO% predicted: 78.1 ± 16 vs. 90 ± 6 %, respectively, p = 0.04; KCO% predicted: 77 ± 16 vs. 93 ± 5 %, p = 0.02, respectively). None of the lung function parameters correlated with duration of the disease, or with inflammatory marker of the airways. In acromegalics, biological (exhaled NO concentrations) and imaging (total lung volume, TLV, and mean lung density, MLD) evaluations were within normal values. The TLV measured by HRCT was 3540 ± 1555 ml in acromegalics, and the MLD was -711 ± 73 HU. None of the lung functional, radiological, and biological findings correlated with GH or IGF-I levels, and no correlation was found with duration of disease. CONCLUSIONS: In the current study, lung function evaluation allowed to detect early involvement of lung parenchyma, as assessed by TLCO and KCO, even in the absence of parenchymal density alterations of the lung by HRCT. These findings suggest to routinely include the carbon monoxide diffusing capacity in the lung function assessment for an early intervention in acromegaly

Chest radiography practice in critically ill patients: a postal survey in the Netherlands

BACKGROUND: To ascertain current chest radiography practice in intensive care units (ICUs) in the Netherlands. METHODS: Postal survey: a questionnaire was sent to all ICUs with > 5 beds suitable for mechanical ventilation; pediatric ICUs were excluded. When an ICU performed daily-routine chest radiographs in any group of patients it was considered to be a "daily-routine chest radiography" ICU. RESULTS: From the number of ICUs responding, 63% practice a daily-routine strategy, in which chest radiographs are obtained on a daily basis without any specific reason. A daily-routine chest radiography strategy is practiced less frequently in university-affiliated ICUs (50%) as compared to other ICUs (68%), as well as in larger ICUs (> 20 beds, 50%) as compared to smaller ICUs (< 20 beds, 65%) (P > 0.05). Remarkably, physicians that practice a daily-routine strategy consider daily-routine radiographs helpful in guiding daily practice in less than 30% of all performed radiographs. Chest radiographs are considered essential for verification of the position of invasive devices (81%) and for diagnosing pneumothorax, pneumonia or acute respiratory distress syndrome (82%, 74% and 69%, respectively). On demand chest radiographs are obtained after introduction of thoracic drains, central venous lines and endotracheal tubes in 98%, 84% and 75% of responding ICUs, respectively. Chest films are also obtained in case of ventilatory deterioration (49% of responding ICUs), and after cardiopulmonary resuscitation (59%), tracheotomy (58%) and mini-tracheotomy (23%). CONCLUSION: There is notable lack of consensus on chest radiography practice in the Netherlands. This survey suggests that a large number of intensivists may doubt the value of daily-routine chest radiography, but still practice a daily-routine strategy

Insights to scaling remote plasma sources sustained in NF3 mixtures

Remote plasma sources (RPSs) are being developed for low damage materials processing during semiconductor fabrication. Plasmas sustained in NF3 are often used as a source of F atoms. NF3 containing gas mixtures such as NF3/O2 and NF3/H2 provide additional opportunities to produce and control desirable reactive species such as F and NO. In this paper, results from computational investigations of RPS sustained in capacitively coupled plasmas are discussed using zero-dimensional global and two-dimensional reactor scale models. A comprehensive reaction mechanism for plasmas sustained in Ar/NF3/O2 was developed using electron impact cross sections for NF2 and NF calculated by ab initio molecular R-matrix methods. For validation of the reaction mechanism, results from the simulations were compared with optical emission spectroscopy measurements of radical densities. Dissociative attachment and dissociative excitation of NFx are the major sources of F radicals. The exothermicity from these Franck–Condon dissociative processes is the dominant gas heating mechanism, producing gas temperatures in excess of 1500 K. The large fractional dissociation of the feedstock gases enables a larger variety of end-products. Reactions between NFx and O atom containing species lead to the formation of NO and N2O through endothermic reactions facilitated by the gas heating, followed by the formation of NO2 and FNO from exothermic reactions. The downstream composition in the flowing afterglow is an ion–ion plasma maintained by, in oxygen containing mixtures, [F−] ≈ [NO+] since NO has the lowest ionization potential and F has the highest electron affinity among the major neutral species

Non-emphysematous chronic obstructive pulmonary disease is associated with diabetes mellitus

Background: Chronic obstructive pulmonary disease (COPD) has been classically divided into blue bloaters and pink puffers. The utility of these clinical subtypes is unclear. However, the broader distinction between airway-predominant and emphysema-predominant COPD may be clinically relevant. The objective was to define clinical features of emphysema-predominant and non-emphysematous COPD patients. Methods: Current and former smokers from the Genetic Epidemiology of COPD Study (COPDGene) had chest computed tomography (CT) scans with quantitative image analysis. Emphysema-predominant COPD was defined by low attenuation area at -950 Hounsfield Units (LAA-950) ≥10%. Non-emphysematous COPD was defined by airflow obstruction with minimal to no emphysema (LAA-950 < 5%). Results: Out of 4197 COPD subjects, 1687 were classified as emphysema-predominant and 1817 as non-emphysematous; 693 had LAA-950 between 5-10% and were not categorized. Subjects with emphysema-predominant COPD were older (65.6 vs 60.6 years, p < 0.0001) with more severe COPD based on airflow obstruction (FEV1 44.5 vs 68.4%, p < 0.0001), greater exercise limitation (6-minute walk distance 1138 vs 1331 ft, p < 0.0001) and reduced quality of life (St. George's Respiratory Questionnaire score 43 vs 31, p < 0.0001). Self-reported diabetes was more frequent in non-emphysematous COPD (OR 2.13, p < 0.001), which was also confirmed using a strict definition of diabetes based on medication use. The association between diabetes and non-emphysematous COPD was replicated in the ECLIPSE study. Conclusions: Non-emphysematous COPD, defined by airflow obstruction with a paucity of emphysema on chest CT scan, is associated with an increased risk of diabetes. COPD patients without emphysema may warrant closer monitoring for diabetes, hypertension, and hyperlipidemia and vice versa