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Biomedical subjects

P Casan

Publications and source records attributed to P Casan.

At least 19 recordsLinked to original sources
PubMed2006

Inspired oxygen fraction achieved with a portable ventilator: determinant factors.

INTRODUCTION: Non-invasive positive pressure ventilation (NIPPV) is an effective treatment in respiratory failure. Continuous positive pressure (CPAP) may also be useful in acute hypoxaemic patients. Supplementary oxygen is usually necessary in both systems. However, the inspired oxygen fraction (FiO2) delivered by a NIV portable ventilator is unknown. The main objectives of this study were to establish the maximal FiO2 that could be achieved by these devices and to analyse the FiO2 determinant factors. METHOD: Ten healthy volunteers were evaluated using a BiPAP ST30 ventilator (Respironics, USA) with a single-limb circuit, expiratory port and nasal mask (Respironics, USA). Oxygen (15 L/min) was administered at two connection points (proximal and distal). Each volunteer carried out a NIPPV (inspiratory pressure 20 cmH2O [1.95 kPa]-expiratory pressure 8 cmH2O [0.78 kPa]) and a CPAP (10 cmH2O [0.981 kPa]) session. FiO2 was analysed by a probe located in the mask. Minute volume (MV) was measured using a pneumotachograph. RESULTS: Maximal FiO2 was obtained with CPAP and distal oxygen connection point (67.39 +/- 15.39%). NIPPV achieved higher MV than CPAP. FiO2 was inversely correlated with MV. CONCLUSIONS: FiO2 obtained while using a NIPPV portable ventilator depends on the ventilatory assistant mode, the oxygen connection point and the MV reached.

Continuous Positive Airway Pressure↗
PubMed2006

[The relationship between lung function and health-related quality of life in patients with generalized myasthenia gravis].

OBJECTIVE: To study lung function abnormalities and health-related quality of life (HRQL) in a group of patients diagnosed with generalized myasthenia gravis, and to analyze the relationship between these 2 sets of variables. PATIENTS AND METHODS: In a prospective study of 20 patients diagnosed with generalized myasthenia gravis, the following parameters were measured: spirometry, static lung volumes, breathing pattern, maximal respiratory pressures, and maximum voluntary ventilation. HRQL was assessed using the 36-item short form general health questionnaire (SF-36). RESULTS: The mean (SD) age of the patients was 64 (11) years. Patients were classified into 2 groups depending on whether they had IIa (12 patients) or IIb (8 patients) type disease. A small decrease in total lung capacity (86%) and slight reductions in maximal inspiratory pressure (88%) and maximum voluntary ventilation (63% in group IIb) were observed. The HRQL domains most affected were those related to physical activity and self-perceived health status in all groups, although women were more affected. The scores relating to vitality and physical activity were found to be significantly associated with forced vital capacity and lung volumes. Tidal volume was associated with maximal inspiratory and expiratory pressures, inspiratory capacity, and maximum voluntary ventilation. The respiratory rate to tidal volume ratio was inversely associated with the first three of these variables. CONCLUSIONS: A very slight restrictive pattern and a reduction in inspiratory muscle strength were observed. The HRQL domains most affected were those related to physical activity and the patients' self-perceived health status. The weakness of the respiratory muscles contributes to the abnormalities observed in lung function and to the deterioration of health-related quality of life.

Aged↗
PubMed2006

[Markers of airway remodeling in induced sputum from healthy smokers].

OBJECTIVE: Airway remodeling in chronic obstructive pulmonary disease (COPD) has been linked to the equilibrium between matrix metalloproteinase (MMP) 9 and its inhibitor, tissue inhibitor of metalloproteinase (TIMP) 1. However, that equilibrium has not been analyzed in healthy smokers. The aim of this study was to assess the equilibrium between MMP-9 and TIMP-1 in induced sputum from healthy smokers, healthy nonsmokers (controls), and patients with COPD. PATIENTS AND METHODS: Samples of induced sputum were obtained from 35 individuals: 12 healthy smokers, 12 controls, and 11 patients with COPD. In each sample, a differential cell count was performed and enzyme-linked immunosorbent assays were used to analyze the concentrations of MMP-9 (total and active fraction) and TIMP-1. RESULTS: Compared with controls, healthy smokers were found to have a higher mean (SD) concentration of total MMP-9 (273 [277] ng/mL vs 128 [146] ng/mL) and a higher ratio of total MMP-9 to TIMP-1 (0.16 [0.14] vs 0.08 [0.06]). However, the ratio of active MMP-9 to TIMP-1 was similar in the 2 groups. Samples from patients with COPD had the highest concentrations of total MMP-9 (477 [262] ng/mL) and active MMP-9 (178 [126] ng/mL) and the lowest concentrations of TIMP-1 (1.044 [1.036] microg/mL). When all groups were considered together, there was an inverse relationship between the MMP-9/TIMP-1 ratio and the forced expiratory volume in the first second (FEV1). The relationship between the active MMP-9/TIMP-1 ratio and FEV1 was even stronger, and the relation of both ratios with FEV1 became stronger still when smoking was considered. CONCLUSIONS: Healthy smokers had a higher concentration of total MMP-9 and that concentration was correlated with their exposure to tobacco smoke. Maintenance of the active MMP-9/TIMP-1 ratio in healthy smokers may explain the absence of progressive airway obstruction. Measurement of active MMP-9 concentration could be useful for assessment of airway remodeling.

Adult↗
PubMed2005

[Bronchial exudate of serum proteins during asthma attack].

OBJECTIVE: Although altered vascular permeability and edema of the bronchial mucosa are associated with asthma attack, their influence on its severity remains unknown. We address this issue by comparing relative indices for the concentration of albumin (RIAlb) and alpha2-macroglobulin (RIalpha2M) in induced sputum and peripheral blood from patients with exacerbated asthma, patients with stable asthma, and control subjects. PATIENTS AND METHODS: Forty-six volunteers participated in the study: 14 with exacerbated asthma (forced expiratory volume in the first second [FEV1] 74.3% [SD, 20.8%] of reference), 23 with stable asthma (FEV1 93.6% [7.5%]), and 9 controls (FEV1 101.1% [9.9%]). The concentrations of albumin and alpha2-macroglobulin were quantified by immunoturbidimetry and immunonephelometry, respectively. The relative index was then calculated by dividing the concentration in sputum supernatant by the concentration in peripheral blood. RESULTS: The mean RIAlb was 1.2 (1.1) in the control group, 2.9 (3.1) in the stable asthma group, and 6.0 (6.7) in the exacerbated asthma group. The RIalpha2M values were 11.7 (10.9), 11.9 (14.7), and 3.2 (3.8) for the control group and stable and exacerbated asthma groups, respectively. The increases in the RIAlb values between all groups, and the decrease in the RIalpha2M value between the exacerbated asthma and control groups were statistically significant (P<.05). The percentage of neutrophils, but not of eosinophils, in sputum was correlated with the RIAlb (r=0.39; P=.008) but not the RIalpha2M (r=-0.035; P=.82). FEV1 displayed an inverse relationship with the RIAlb (r=-0.43; P=.009) but not with the RIalpha2M (r=-0.206; P=.24). No correlation was found between oxyhemoglobin saturation and either the RIAlb (r=-0.33; P=.19) or the RIalpha2M (r=-0.12; P=.84). CONCLUSIONS: Vascular permeability is altered during asthma exacerbations and appears to be correlated with the presence of neutrophils and the degree of bronchial obstruction.

Acute Disease↗
PubMed2005

[Expansion of primary bronchial epithelial cell cultures].

OBJECTIVE: Cell cultures provide a good model for studying lung diseases but they are difficult to reproduce and the number of cells obtained is limited. The aim of this study was to develop a way to increase the production of human bronchial epithelial cells (BEC) in primary cultures. MATERIAL AND METHODS: A total of 12 samples (9 from surgical specimens and 3 from endoscopic biopsies) were processed on plates coated with type I collagen with growth medium supplemented for BEC. When cell proliferation started, the explants were removed for successive subculturing. The remaining cells were left to proliferate and were trypsinized after 50% confluence. We recorded the number of cells obtained, cell viability, and the percentage positive for cytokeratin 7. RESULTS: The total number of cells obtained by this method was 3-fold the number of human BEC obtained with simple primary cultures. The maximum number of subcultures was 5, mean (SD) cell viability was 91.9% (11.7%), and the percentage of cells positive for cytokeratin 7 was 30.71% (10.68%). CONCLUSIONS: The described method for expanding primary BEC cultures increases cell production.

Aged↗
PubMed2005

[Exhaled breath condensate: standardized collection of samples from healthy volunteers].

Expired breath condensate collection is a noninvasive technique for obtaining a sample in which to analyze substances that reflect the functional status of the lung and other tissues. Twenty healthy volunteers provided 3 expired breath samples: the second was collected 20 minutes after the first and the third 48 hours after the first. The air and condensate volumes were assessed. The mean (SD) volume of condensate in exhaled air over a period of 15 minutes was 1.8 (0.5) mL (95% confidence interval [CI], 1.5-2 mL) and the coefficient of variation was 29%. Analysis of variance in the 3 samples demonstrated no significant differences. The mean volume of air inhaled over 15 minutes was 119 (25) L (95% CI, 112-125 L). These results indicate that it takes at least 15 minutes and the inhalation of some 120 L of air to collect a condensate volume that exceeds 1.5 mL, sufficient to allow distribution in aliquots to analyze fundamental physical and chemical properties (conductivity, pH) and certain relevant biomarkers.

Adult↗
PubMed2004

[Spirometry at home: technology within the patient's reach].

Spirometry is a basic lung function test useful both for measuring and for monitoring expiratory volume. For many years monitoring has been performed by means of a portable peak flow meter capable of measuring maximal expiratory flow. We present a portable spirometer (Spirotel, Medical International Research, Rome, Italy) capable of transmitting stored lung function data from the patient's home by telephone. The device is easy to use, presents information graphically and numerically, and allows degrees of change in lung function to be monitored on-line. It may be useful for controlling asthma and work-related respiratory diseases.

Adult↗
PubMed2004

[Lung function in cardiac dysfunction].

OBJECTIVE: The alterations in lung function caused by heart failure were first described some decades ago. The advent of new tools for the diagnosis and investigation of heart disease, such as echocardiography, has subsequently made it possible to classify cardiac dysfunction with greater precision. The objective of this study was to analyze and compare a series of lung function and gas exchange variables in patients who had been classified into 4 groups according to type of heart disease as diagnosed by echocardiography. MATERIALS AND METHOD: Emergency room patients whose main symptom was acute dyspnea caused by cardiac or respiratory disease were included in the study. The final sample comprised 71 patients whose echocardiogram revealed cardiac dysfunction. Spirometry was carried out and resting arterial blood gases measured in this group. RESULTS: Of the 71 patients with cardiopathy, 31 had systolic dysfunction, 27 diastolic dysfunction, 7 cor pulmonale, and 6 primary valve disease. Spirometry revealed a generally obstructive pattern, more marked in the group with cor pulmonale. Analysis of arterial blood gases revealed slight hypoxemia with normocapnia in all groups, but this was more accentuated in the patients with cor pulmonale and diastolic dysfunction. An analysis of the correlations (Pearson's r) between cardiac and pulmonary variables revealed the statistically significant associations between cardiac mass and other variables to be as follows: forced vital capacity r=0.34 (P=.02), forced expiratory volume in one second r=0.526 (P=.0001), forced expiratory volume in one second as a percentage of predicted r=0.3 (P=.037), and forced midexpiratory flow rate r=0.31 (P=.03). The correlation between left ventricular ejection fraction and PaO2 was r=-0.312 (P=.01); the correlation between left ventricular end-diastolic diameter and PaO2 was r=0.369 (p=.006). CONCLUSIONS: In patients with cardiac dysfunction, spirometry reveals a generally obstructive pattern, which is more accentuated in patients with right ventricular dysfunction owing to the existence of prior lung disease. The associations found between the cardiac and lung function variables do not help the physician to determine the predominant diagnosis for a patient more precisely or to establish a prognosis.

Adult↗
PubMed2004

Lung cancer pulse oximetry and capnography in lung function laboratories.

OBJECTIVE: To compare values reflecting oxyhemoglobin saturation obtained by pulse oximetry (SpO2) and values for end-tidal carbon dioxide pressure (PETCO2) obtained by capnography with direct measures of gas saturation values and pressures (PaO2 and PaCO2) in arterial blood gas samples. PATIENTS AND METHODS: We studied 57 consecutive patients ranging in age from 34 to 83 years--16 of whom were smokers--who presented for lung function testing. RESULTS: The mean (SD) SpO2 was 95% (2.4%), and oxygen saturation measured directly in arterial blood samples was 95.1% (2.3%) (P=NS). The mean PETCO2 was 37.9 (5.3) mm Hg and PaCO2 by arterial blood gas analysis was 40.6 (5.4) mm Hg (P<.0001). The correlation between the 2 measurements of oxygen saturation (SpO2 and direct assessment) was 0.806 (P<.0001), and the correlation between PETCO2 and PaCO2 was 0.845 (P<.0001). The mean difference between the 2 expressions of oxygen saturation was 0.08% (1.46%) and between PETCO2 and PaCO2 was 2.7 (2.9) mm Hg. CONCLUSION: Both measurement devices (pulse oximeter and capnograph) are appropriate for use in a lung function laboratory. The difference between PETCO2 and the PaCO2 should be kept in mind.

Adult↗
PubMed2004

[Comparison of arterial blood sample kits].

Most inaccuracies in the analysis of gases and electrolytes in arterial blood samples are due to preanalytic factors, among which is the type of equipment used for blood collection. Our objective was to compare arterial blood gas sample kits used under clinical conditions and to evaluate the impact of delay in estimation on variability in results. In 2 types of study we compared 5 kits (Radiometer's Pico 70, Becton Dickinson's Preset, SIMS Portex's Pro-Vent, SIMS-Concord's Pulsator, and Marquest's Quick ABG). In the first study kitsyringe assignment was randomized for collecting arterial blood samples from 160 consecutive patients to evaluate practical aspects of using them and the presence of bubbles in the samples taken. The second study evaluated the effects of delays of 30 and 60 minutes in estimation and of the type of heparin used in 54 blood samples. The kits which produced the fewest bubbles, gave samples with the greatest stability, and had the least impact on ion concentration were Radiometer's Pico 70 and SIMS-Portex's Pro-vent.

Blood Gas Analysis↗
PubMed2004

[Patient preference in the choice of dry powder inhalers].

OBJECTIVE: To investigate a group of patients' preferences among 3 dry powder inhalers--Accuhaler, Easyhaler, and Turbuhaler--and to analyze the features that were most important for motivating choices. MATERIAL AND METHOD: The study enrolled 30 patients with stable asthma with a mean (SD) age of 40 (13) and who habitually used inhaled corticosteroids. The patients were shown in detail how to use each of the devices and were randomized to begin using them in different orders. After using each inhaler for a week, the patients assessed 9 different features on a scale of 0 to 10 with an independent observer. The patients were asked to put the inhalers in order of preference, and finally to demonstrate they could use them correctly. RESULTS: All patients correctly performed the inhalation maneuver at the beginning and the end of the study. The mean final scores out of 90 of the 9 features evaluated were 75 (13) for the Easyhaler, 67 (12) for the Accuhaler, and 65 (14) for the Turbuhaler. Differences were statistically significant between the first and the second device (P=0.02) and the first and the third (P=.001) but not between the Accuhaler and the Turbuhaler (P=.376). Mean rating scores were 8.6 (1.4) for the Easyhaler, 7.3 (1.9) for the Turbuhaler, and 7.1 (1.6) for the Accuhaler. The Easyhaler was the first choice for 53% of patients, the Turbuhaler for 27%, and the Accuhaler for 20%. CONCLUSIONS: The Easyhaler was rated the highest by the patients in the study. The scores were a long way from the maximum score, so research into developing an ideal inhaler must continue.

Adult↗
PubMed2003

Effect of montelukast added to inhaled budesonide on control of mild to moderate asthma.

BACKGROUND: Proinflammatory leukotrienes, which are not completely inhibited by inhaled corticosteroids, may contribute to asthmatic problems [corrected]. A 16 week multicentre, randomised, double blind, controlled study was undertaken to study the efficacy of adding oral montelukast, a leukotriene receptor antagonist, to a constant dose of inhaled budesonide. METHODS: A total of 639 patients aged 18-70 years with forced expiratory volume in 1 second (FEV(1)) > or =55% predicted and a minimum predefined level of asthma symptoms during a 2 week placebo run in period were randomised to receive montelukast 10 mg (n=326) or placebo (n=313) once daily for 16 weeks. All patients received a constant dose of budesonide (400-1600 microg/day) by Turbuhaler throughout the study. RESULTS: Mean FEV(1) at baseline was 81% predicted. The median percentage of asthma exacerbation days was 35% lower (3.1% v 4.8%; p=0.03) and the median percentage of asthma free days was 56% higher (66.1% v 42.3%; p=0.001) in the montelukast group than in the placebo group. Patients receiving concomitant treatment with montelukast had significantly (p<0.05) fewer nocturnal awakenings and significantly (p<0.05) greater improvements in beta agonist use and morning peak expiratory flow rate (PEFR). CONCLUSIONS: For patients with mild airway obstruction and persistent asthma symptoms despite budesonide treatment, concomitant treatment with montelukast significantly improves asthma control.

Acetates↗
PubMed2002

[Lung function in the course of amyotrophic lateral sclerosis].

We report a case of a 26 year old man who was diagnosticated of ALS. This case is a graphic example of the pulmonary function evolution through the flow-volume loop. In the first study the espirometric values were in the normal range. The Static pulmonary pressures were weackle decreased. This was the only sign of respiratory muscle impairement. Its important to study close enough the pulmonary function through the flow/volume loop, maximal respiratory pressures and maximal voluntary Ventilation in order to know the empairment rate, and also to detect intercurrent procedures as bulbar involvement, that can affect the prognosis of the disease.

Adult↗
PubMed2001

[Analysis of the impact of Archivos de Bronconeumología through the Science Citation Index].

OBJECTIVE: To describe the impact factor of Archivos de Bronconeumología from 1997 until 2000 and to identify the patterns of citation of the journal and topics having the greatest impact. METHOD: SCISEARCH was used to locate citations of articles published by Archivos de Bronconeumología between 1995 and 1999. The following data were collected for each article: year of publication, authors, journal, country of publication, language, specialty or specialties, institution(s), residence of the first author and topic. The impact factor was calculated as the ratio of citations received in one year by articles published in Archivos de Bronconeumología during the two previous years and the total number of articles published by Archivos de Bronconeumología over the two years under study. RESULTS: The impact factor of Archivos de Bronconeumología was 0.107 in 1997, 0.089 in 1998, 0.105 in 1999 and 0.119 in 2000. Citations were found in a wide range of source journals, with respiratory system publications having little weight. Citations were made mainly by Spanish authors (75%) and self-citation was restrained (21.1%). Topics related to tuberculosis and respiratory infections (23.6% of the citations received) and chronic obstructive pulmonary disease (12.5%) made the greatest impact. CONCLUSION: The impact factor of Archivos de Bronconeumología is modest, although higher than those of some other publications included in Journal Citation Reports.

Databases, Bibliographic↗
PubMed2001

Mild exacerbations and eosinophilic inflammation in patients with stable, well-controlled asthma after 1 year of follow-up.

OBJECTIVES: To determine the time to exacerbation and probability of a mild exacerbation of asthma, and the impact of eosinophilic inflammation on these parameters in patients with stable, well-controlled asthma. PATIENTS AND METHODS: A cohort of 31 patients with stable, well-controlled asthma receiving inhaled steroid treatment regularly were followed up for 1 year or until a mild exacerbation occurred. Mild exacerbation was defined as symptoms of asthma lasting > 48 h with a fall in peak expiratory flow > 20%. FEV(1), provocative concentration of methacholine causing a 20% fall in FEV(1), eosinophil count, and eosinophilic cationic protein (ECP) levels in blood and in sputum were measured at the first visit and every 2 months. RESULTS: At baseline, the mean (SD) eosinophil count was 0.39 x 10(9)/L (0.21 x 10(9)/L) in blood and 13% (14%) in sputum; ECP was 30 microg/L (28 microg/L) in blood and 75 microg/L (85 microg/L) in sputum. Thirteen subjects experienced a mild exacerbation during the 1-year follow-up period. The mean time to mild exacerbation was 293 days (95% confidence interval [CI], 248 to 337 days), and the cumulative probability of not experiencing a mild exacerbation in 1 year was 49% (95% CI, 39 to 59%). An increased risk of mild exacerbation was associated with blood eosinophil count > 0.4 x 10(9)/L (relative risk 4.5; 95% CI of relative risk, 1.8 to 38.0), blood ECP > 20 microg/L (relative risk, 2.1; 95% CI of relative risk, 1.0 to 9.2), and sputum ECP > 40 microg/L (relative risk, 2.5; 95% CI of relative risk, 1.2 to 11.2), but was unassociated with other variables. CONCLUSIONS: Patient with stable, well-controlled asthma are at risk of mild exacerbation during 1 year of follow-up despite regular inhaled steroid treatment. Eosinophilic inflammation expressed as eosinophil count and ECP is associated with higher risk of mild exacerbation.

Administration, Inhalation↗