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Methacholine Challenge Test (methacholine + challenge_test)
Selected AbstractsResistance and reactance in oscillation lung function reflect basal lung function and bronchial hyperresponsiveness respectivelyRESPIROLOGY, Issue 7 2009Hyeong Yoon KIM ABSTRACT Background and objective: Currently there are few data available regarding the use of impulse oscillometry parameters to assess airflow obstruction during standardized methacholine challenge testing. Methods: Methacholine challenge tests were performed using impulse oscillometry and conventional spirometry in 64 healthy and 39 asthmatic children, in order to determine airway resistance (R) and reactance (X) at frequencies of 5,35 Hz, as well as FEV1. Results: Baseline R and X were significantly different between the healthy and asthmatic children, with the most discriminating parameter being resistance at 5 Hz (R5). In asthmatic children BHR was well demonstrated by FEV1, X5 and X10, but not by R5. However, when the actual R5 values obtained in this study were compared with the predicted values, there appeared to be differences in the lung function measures that corresponded to varying methacholine concentrations. In addition, the PC20_FEV1 and PC70_X5 were significantly more sensitive than other parameters for methacholine challenge testing. Conclusions: Measuring resistance at 5 Hz using impulse oscillometry facilitates significant differentiation of baseline lung function between asthmatic and healthy children. Additionally, X may be a suitable replacement for PC20 in methacholine challenge testing. [source] Rapid and efficient mapping of regional ventilation in the rat lung using hyperpolarized 3He with Flip angle variation for offset of RF and relaxation (FAVOR)MAGNETIC RESONANCE IN MEDICINE, Issue 6 2008Giles E. Santyr Abstract A novel imaging method is presented, Flip Angle Variation for Offset of RF and Relaxation (FAVOR), for rapid and efficient measurement of rat lung ventilation using hyperpolarized helium-3 (3He) gas. The FAVOR technique utilizes variable flip angles to remove the cumulative effect of RF pulses and T1 relaxation on the hyperpolarized gas signal and thereby eliminates the need for intervening air wash-out breaths and multiple cycles of 3He wash-in breaths before each image. The former allows an improvement in speed (by a factor of ,30) while the latter reduces the cost of each measurement (by a factor of ,5). The FAVOR and conventional ventilation methods were performed on six healthy male Brown Norway rats (190,270 g). Lobar measurements of ventilation, r, obtained with the FAVOR method were not significantly different from those obtained with the conventional method for the right middle and caudal and left lobes (P > 0.05 by a Wilcoxon matched pairs test). A methacholine challenge test was also administered to an animal and reduction and recovery of r was detected by the FAVOR method. The reduced 3He consumption and the improvement in speed provided by FAVOR suggest that it may allow measurement of ventilation in human subjects not previously possible. Magn Reson Med 59:1304,1310, 2008. © 2008 Wiley-Liss, Inc. [source] Airway reactivity in children before and after stem cell transplantationPEDIATRIC PULMONOLOGY, Issue 9 2009Lea Bentur MD Abstract Stem cell transplantation (SCT) is associated with pulmonary complications. We encountered several children post-SCT with a clinical picture suggestive of airway hyper-reactivity (AHR) and evidence of reversible airway obstruction that was not reported pre-transplant. We evaluated the possibility of increased AHR as assessed by methacholine challenge test (MCT) following the course of SCT, and assessed a possible correlation between AHR and pulmonary complications. This was a prospective study evaluating consecutive patients referred for SCT to the Department of Pediatric Hemato-Oncology. Evaluation included pulmonary function test and MCT before and after SCT, and assessment of pulmonary complications. Twenty-one of 33 patients completed the study. The mean PC20 was 14.3,±,4.1 mg/ml prior to SCT; afterward the mean PC20 decreased to 11.2,±,5.6 mg/ml (P,=,0.018). The number of patients with airway reactivity (PC20,,,8 mg/ml) increased from 2/21 patients before SCT to 8/21 patients after SCT (P,=,0.043; McNemar test with Yates correction). Pulmonary complications and hospitalization were recorded in 33.3% of the patients (7/21 patients): 62.5% of the patients (5 patients) with AHR compared to 15.4% (2 patients) in the group without AHR (P,=,0.041; Fisher exact test). There were 10 hospitalizations among the 8 patients with positive MCT compared to 2 hospitalizations in 13 patients with negative MCT (median 1 vs. 0, P,=,0.045; Mann,Whitney U -test). Increased airway reactivity was observed in our study following the course of SCT. Positive MCT after SCT may be associated with increased risk of pulmonary complications. Larger prospective studies are needed to evaluate the possible mechanisms responsible for increased AHR and the clinical importance of these findings. Pediatr Pulmonol. 2009; 44:845,850. © 2009 Wiley-Liss, Inc. [source] The potential use of spirometry during methacholine challenge test in young children with respiratory symptomsPEDIATRIC PULMONOLOGY, Issue 7 2009Daphna Vilozni PhD Abstract Background The concentration of methacholine that causes a fall of 20% from baseline forced expiratory volume in the first second (PC20-FEV1) in the methacholine challenge test (MCT) is not usually considered a diagnostic tool in preschool children since PC20-FEV1 may not be achievable <6 years of age. Aim To assess the usefulness of various spirometry indices obtained during MCT in a large group of 3- to 6-year-old children with respect to their clinical diagnosis. Methods Standardized MCT (inhaled triple-concentration increments [0.057,13.925 mg] of methacholine solution) was performed by 84 children previously diagnosed with asthma (asthmatics) and 48 with prolonged cough (coughers). Spirometry was determined at baseline and between inhalations; PC20-FEV1 and PC25-FEV0.5 were calculated. Results PC20-FEV1 values were significantly less in the asthmatics than in the coughers (mean,±,SD was 3.21,±,4.32 vs. 22.35,±,3.66 ml/mg). Similarly, PC25-FEV0.5 was 1.48,±,3.08 in the asthmatics and 9.45,±,12.59 mg/ml/Mch in the coughers, P,<,0.0001. A cut-off at 4.0 mg/ml for PC20-FEV1 had 77.4% sensitivity and 75.0% specificity, a cut-off at 2.2 mg/ml for PC25-FEV0.5 had 73.8% sensitivity and 72.9% specificity, for clinical diagnosis of asthma. PC25-FEV0.5 also showed a correlation with age. Conclusions Our findings suggest that MCT can be performed in preschool children with various respiratory symptoms. PC25-FEV0.5 may be a better end-point parameter. Children with a clinical diagnosis of asthma respond to a lower MCT concentration than children with cough. Further studies are needed to determine airway responsiveness in healthy young children and to further assess the contribution of MCT to the clinical diagnosis in this age group. Pediatr Pulmonol. 2009; 44:720,727. © 2009 Wiley-Liss, Inc. [source] Inhaled corticosteroid for persistent cough following upper respiratory tract infectionRESPIROLOGY, Issue 4 2005Prapaporn PORNSURIYASAK Objective: The aim of this study was to determine the clinical effect of inhaled corticosteroid treatment for persistent cough, post upper respiratory tract infection (URTI) in previously healthy individuals, and on bronchial hyperresponsiveness (BHR). Methodology: This was a prospective, randomized, double-blinded, placebo-controlled study conducted at a university hospital. A total of 30 non-asthmatic, non-smoking patients who were >15 years old and who had persistent post-URTI cough for >3 weeks were assessed by a physical examination, CXR and spirometry, and were allocated to receive inhaled budesonide (400 µg/puff, twice daily) or placebo for 4 weeks. If a patient suffered from sinusitis, it was a requirement that it had been well treated. A symptom score (frequency of cough, frequency of coughing bouts, symptoms associated with cough, night-time cough, frequency of taking medications to relieve cough, and number of medications) was recorded at entry, and after 2 and 4 weeks of treatment. A methacholine challenge test was performed at entry and after 4 weeks of treatment. Results: The mean symptom scores for the treatment group (9.4) and the placebo group (9.8) at baseline were not significantly different (P = 0.79), and no differences were found between the groups after week 2 and week 4 of treatment (3.93 and 4.27 vs 2.26 and 2.66, P = 0.29). The mean change in symptom scores from baseline to week 2 and to week 4 of treatment were also not different between groups (5.93 and 5.6 vs 7.00 and 7.58, P = 0.23). No difference between groups was found in the mean changes in FEV1, FVC, and FEF25,75% after 4 weeks of treatment. A positive bronchial provocation test occurred in three patients (10%) but these were borderline. Conclusion: Inhaled corticosteroid is ineffective in treating persistent post-URTI cough in previously healthy individuals. [source] The bronchial response to mannitol is attenuated by a previous methacholine test: but not vice versaCLINICAL & EXPERIMENTAL ALLERGY, Issue 7 2009E. Gade Summary Aim To examine the airway response to inhaled mannitol performed before or after a methacholine challenge test in a group of asthmatics with different levels of disease. Methods A total of 48 asthmatics, 18,73 years of age, were included in the study. Two pairs of challenges were performed in a random order on two separate days 24 h apart: either with mannitol performed first on day one, followed 1 h by methacholine, and methacholine as the first on day two, followed 1 h by mannitol or vice versa. A questionnaire-based interview was performed and lung function, exhaled nitric oxide, skin prick test, and blood eosinophil count were measured. Results A total of 44% of the asthmatics used inhaled corticosteroids and 48% were atopic. The airway response to mannitol was attenuated when mannitol was given after methacholine, compared with the response to mannitol when it was given first [log response dose ratio (RDR): 1.42 vs. 1.60 (P=0.004)], whereas the response to methacholine was unchanged in the opposite test order [log RDR: 0.81 vs. 0.96 (P=0.102)]. Conclusion Bronchial challenges with inhaled mannitol and methacholine may be performed on the same day but provocation with mannitol should be performed before methacholine. [source] Relationship between adipokines and manifestations of childhood asthmaPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 6 2008Kyung W. Kim Although the prevalences of asthma and obesity are increasing substantially in recent decades, very little is known about the possible association between them. We evaluated the roles of leptin, adiponectin, and resistin, which are adipokines produced by adipose tissue, on childhood asthma, and their association with pulmonary function and bronchial hyperresponsiveness. We studied 149 atopic asthmatic children, 37 non-atopic asthmatic children, and 54 healthy children. Body mass index was calculated using height and weight, which were measured on the same day that pulmonary function tests and methacholine challenge tests were performed. Skin prick tests were performed, and total eosinophil count, total serum immunoglobulin E (IgE), serum eosinophil cationic protein, leptin, adiponectin, and resistin were measured in all subjects. Atopic asthmatics had lower resistin levels compared with non-atopic asthma and control groups, but leptin and adiponectin did not show any difference among these three groups. Resistin demonstrated positive correlation with methacholine PC20 and negative correlations with eosinophil count and serum total IgE. Leptin and adiponectin showed associations with forced expiratory volume in 1 s or forced expiratory flow between 25,75%. Multiple regression analysis revealed that resistin was a significant predictive factor for asthma. There was no direct association between asthma and leptin or adiponectin. Our findings suggest that resistin may play a negative predictive role in asthma. Adiponectin and leptin showed close associations with pulmonary function and may have disease-modifying effects in children with asthma. [source] Effect of active smoking on asthma symptoms, pulmonary function, and BHR in adolescents ,PEDIATRIC PULMONOLOGY, Issue 10 2009S. Yoo MD Abstract Background Active smoking is known to increase asthma symptoms and bronchial hyper-responsiveness (BHR) while decreasing pulmonary function in adults, but few studies have addressed these issues in adolescents. Methods We conducted a cross-sectional survey involving questionnaires and assessment of urinary cotinine levels among 1,492 adolescents from three urban areas of South Korea. Current smoking was defined as having smoked more than 1 day in the prior 30 days or having urine cotinine levels ,100,ng/ml. Spirometry, skin tests, and methacholine challenge tests were performed on adolescents in Seoul (n,=,724). Results The prevalence of current smoking was 8.2% in boys and 2.4% in girls. Reports of wheeze and exercise-induced wheeze in the previous 12 months were more frequent in smokers than nonsmokers (15.2% vs. 8.5%, P,=,0.024, and 20.4% vs. 10.7%, P,=,0.004, respectively). In multiple logistic regression analysis, current smoking was found to be a significant risk factor for having wheezed in previous 12 months (OR,=,4.5, 95% CI 1.5,13.2) and having exercise-induced wheezing in previous 12 months (OR,=,8.7, 95% CI, 3.7,20.9). The subgroup analysis revealed that the FEV1/FVC was lower in smokers than nonsmokers (mean,±,SD, 105.1,±,8.6% vs. 107.8,±,7.8%, P,=,0.019). In contrast, there was no significant difference in BHR. The effect of smoking on asthma symptoms were more pronounced in non-atopic compared with atopic adolescents. Conclusion Current smoking was significantly associated with symptoms of asthma, such as having recent wheezing and recent exercise-induced wheezing, especially for non-atopics, in Korean adolescent population. Current smoking was further associated with lower pulmonary function, but not BHR. Pediatr Pulmonol. 2009; 44:954,961. ©2009 Wiley-Liss, Inc. [source] Occupational allergy and asthma among salt water fish processing workersAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 12 2008Mohamed F. Jeebhay MBChB Abstract Background Fish processing is a common economic activity in Southern Africa. The aim of this study was to determine the prevalence and host determinants of allergic symptoms, allergic sensitization, bronchial hyper-responsiveness and asthma among workers processing saltwater fish. Methods A cross-sectional study was conducted on 594 currently employed workers in two processing plants involved in pilchard canning and fishmeal processing. A modified European Community Respiratory Health Survey (ECRHS) questionnaire was used. Skin prick tests (SPT) used extracts of common airborne allergens, fresh fish (pilchard, anchovy, maasbanker, mackerel, red eye) and fishmeal. Spirometry and methacholine challenge tests (MCTs; tidal breathing method) used ATS guidelines. Results Work-related ocular-nasal symptoms (26%) were more common than asthma symptoms (16%). The prevalence of atopy was 36%, while 7% were sensitized to fish species and 26% had NSBH (PC20,,,8 mg/ml or ,12% increase in FEV1 post-bronchodilator). The prevalence of probable occupational asthma was 1.8% and fish allergic rhino-conjunctivitis 2.6%. Women were more likely to report work-related asthma symptoms (OR,=,1.94) and have NSBH (OR,=,3.09), while men were more likely to be sensitized to fish (OR,=,2.06) and have airway obstruction (OR,=,4.17). Atopy (OR,=,3.16) and current smoking (OR,=,2.37), but not habitual seafood consumption were associated with sensitization to fish. Conclusions Based on comparison with previous published studies, the prevalence of occupational asthma to salt water fish is lower than due to shellfish. The gendered distribution of work and exposures in fish processing operations together with atopy and cigarette smoking are important determinants of occupational allergy and asthma. Am. J. Ind. Med. 51:899,910, 2008. © 2008 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||