The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Inhalation of heroin is known to provoke asthma. We report on the case of a patient who, after repeated inhalation of heroin, presented with decreased lung volume associated with bronchial hyperresponsiveness, diffuse pulmonary infiltrates, and bronchoalveolar lavage fluid eosinophilia. Rapid remission was obtained after heroin abstinence and initiation of corticosteroid treatment.
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Comparative Study
Parenchymal emphysema measured by CT lung density correlates with lung function in patients with bullous disease.
In subjects with chronic obstructive pulmonary disease (COPD) computed tomographic (CT) lung density correlates with direct pathological measurements of the size of the distal airspaces, as well as with measurements of airflow limitation and impairment of the diffusing capacity. Thus, CT lung density can be used to quantify emphysema in life. We wanted to assess the use of CT scanning to detect and measure the extent of bullous lung, and to quantify the severity of emphysema in the non-bullous areas of the lungs. ⋯ The extent of bullous emphysema correlated poorly with all respiratory function measurements. In contrast, the severity of emphysema in the non-bullous parts of the lungs, expressed as either the mean EMI number, or the EMI number of the lowest 5th percentile of the CT lung density histogram, correlated well with measurements of airflow limitation and diffusing capacity. Our findings, thus, suggest that in patients with bullae the major determinant of respiratory function is the severity of the emphysema in non-bullous lung, and that the extent of the bullae has less functional importance.(ABSTRACT TRUNCATED AT 250 WORDS)
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Eight single lung transplant recipients with emphysema, aged 40-58 yrs, have been followed up for 90 patient months. Starting 2-4 weeks postoperatively, they recorded their forced vital capacity (FVC), and forced expiratory volume in one second (FEV1), at a fixed time every morning using a Micro Spirometer. They were instructed to contact the hospital if the FVC or FEV1 displayed a persistent (two days or more) decrease of 10%, compared with the average values during the last seven days. ⋯ However, FVC and FEV1 decreased significantly (p < 0.001, paired t-test) during rejections (mean percentage change 14 and 21% respectively, range +8% to -53%). In 16 of the 23 rejections, the FEV1 decreased by > 10%. We recommend the use of daily home spirometry when monitoring single lung recipients with emphysema, and suggest that a persistent 10% decrease in FEV1 or FVC for at least two days is an indication for hospital admission and possible TBB.
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The aim of the study was to assess the impact of the intrinsic positive end-expiratory pressure (PEEPi) on pulmonary gas exchange in mechanically-ventilated patients, by comparing the effects of similar levels (0.8-0.9 kPa) of positive end-expiratory pressure (PEEP) and PEEPi. Ten patients with acute respiratory failure, without chronic airway disease, were studied with three ventilatory modes: 1) intermittent positive pressure ventilation with zero end-expiratory pressure (ZEEP mode); 2) continuous positive pressure ventilation with PEEP set by the ventilator (PEEP mode); and 3) intrinsic PEEP elicited by adequate shortening of the expiratory time (PEEPi mode). ⋯ However, the improvement of PaO2 was more consistent (8 out of 10 patients), and larger (+2.1 kPa, on average, p < 0.05) with PEEP than with PEEPi (5 out of 10 patients, and +1.4 kPa, on average, NS). Since the effects of PEEP and PEEPi on ventilation, lung volume, compliance, cardiac output (QT), mixed venous oxygen tension (PvO2) and oxygen consumption (VO2) were similar, we attributed the less favourable impact of PEEPi on PaO2 to a less homogeneous distribution of PEEPi between lung units with different time constant, and hence to a more uneven distribution of the inspired gas.
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An L-arginine-dependent pathway, metabolising L-arginine to citrulline and nitrogen oxides, has been described in many cell types in different species, including man. Two subtypes of this nitric oxide synthase have been reported: a constitutive enzyme type, releasing nitric oxide after stimulation, is typically found in endothelial and neural cells; another subtype can be induced in macrophages after cytokine treatment. This review summarizes the literature on the known and proposed roles of this L-arginine-dependent nitric oxide production in different pulmonary processes. ⋯ The details of the role and distribution of nitric oxide synthase in the (human) lung and airways are not yet completely understood. Nitric oxide is believed to play a role in various pulmonary physiological processes, such as bronchodilation and the cytotoxic action of certain cells. The modulation of nitric oxide release will therefore, most probably lead to application of novel therapies in diseases such as asthma and inflammatory pulmonary diseases.