BACKGROUND: The measurement of nonspecific bronchial hyperreactivity is valuable for diagnosis and management of bronchial asthma. Methacholine or histamine is used for the pharmacologic provocation test. Usually a methacholine bronchial provocation test is performed by a dosing technique with counted number of breaths. A dosimeter is indispensable in the dosing technique. Recently a timed tidal breathing technique which dose not need an expensive dosimeter was introduced. We measured the degree of nonspecific bronchial hyperreactivity to histamine using a simple timed tidal breathing technique. METHOD: Forty two healthy volunteers, 12 patients with bronchial asthma(BA), 10 patients with rhinitis(RH) and 10 patients with upper respiratory infection(URI) participated in the study. The subject's nose was clipped and inhalation continued during tidal breathing for 2 minutes via a face mask. FEV1 was measured at 30 seconds, 90 seconds after inhalation and inhalation of next solution was continued until there was a fall in FEV1 of 20%. Histamine PC20 was defined as the concentration at 20% fall of FEV1 and it was obtained from the log dose-response curve by linear interpolation. RESULTS: Inhalation of serial dilution of histamine could be performed in all patients without significant side of effects. The geometric mean±standard deviation of histamine PC20 in healthy volunteers is 8.27±2.22mg/ml, BA group 0.33±3.02mg/ml, RH group 0.85 ±3.24mg/ml, and URI group 1.47±1.98mg/ml. CONCLUSION: Histamine bronchial provocation test using timed tidal breath method is a simple and suitable tool for management of patients with bronchial hyperreactivity.
Asthma ; Bronchial Hyperreactivity ; Bronchial Provocation Tests* ; Diagnosis ; Healthy Volunteers ; Histamine* ; Humans ; Inhalation ; Masks ; Methacholine Chloride ; Nose ; Respiration*

OBJECTIVETo compare the advantages and disadvantages between exercise challenge test (ECT) and methacholine challenge test (MCT) in the measurement of airway hyperresponsiveness (AHR), in order to identify a better and safer method to measure AHR.

METHODSForty-seven children with controlled asthma after regular treatment were enrolled. ECT and MCT were performed for each child successively, and sensitivity was obtained through comparison with the golden standard (PD20). The occurrence of bronchospasm symptoms during the two tests was recorded.

RESULTSTaking PD20 as the gold standard, in children with moderate or severe AHR, the sensitivity of MCT (61%) for the measurement of AHR was significantly higher than that of ECT (9%) (P<0.05). The consistency between MCT results and PD20 was relatively high (κ=0.614), while the consistency between ECT results and PD20 was relatively low (κ=0.006). However, in the MCT, the incidence of bronchospasm symptoms was high and positively correlated with the incidence of cough and chest distress (P<0.05).

CONCLUSIONSMCT has a higher sensitivity for the measurement of AHR, but has a higher incidence of adverse events, compared with ECT in children with controlled asthma after regular treatment.

Adolescent ; Bronchial Hyperreactivity ; diagnosis ; Child ; Exercise Test ; Female ; Humans ; Male ; Methacholine Chloride ; pharmacology

To validate the prevalence rate of symptoms of asthma produced by the phase I ISAAC (International Study of Asthma and Allergies in Childhood) study, hypertonic saline challenge test was carried out during the phase II study at a year after the phase I study. For the phase II study, six middle schools from three cities in the phase I study were selected. Finally, 499 children who responded to both studies were analyzed. All subjects were asked to complete the written questionnaire (WQ) first, followed by a video questionnaire (AVQ 3.0) during the phase I study. Of the 499 children, only 19 (3.8%) were positive to the hypertonic saline bronchial challenge test. The degree of agreement between responses to the two corresponding questions "wheezing at rest" and "nocturnal wheeze" in the AVQ 3.0 and WQ were moderate and weak with a Kappa indices of 0.45 and 0.23, respectively. The question on "severe wheeze" in the AVQ 3.0 had the highest Youden's index among the five questions related to asthma symptoms in the previous 12 months, but its specificity was low whereas it 's sensitivity was 1.0. There was no consistency of priority between the two questionnaires in predicting bronchial hyperreactivity in a group of Korean schoolchildren. Therefore we need to develop more appropriate WQ or AVQ to compare the prevalences of asthma to other countries.
Adolescent ; Asthma/diagnosis* ; Asthma/epidemiology ; Asthma/etiology ; Bronchial Hyperreactivity/complications ; Bronchial Hyperreactivity/diagnosis* ; Bronchial Hyperreactivity/epidemiology ; Bronchial Provocation Tests ; Comparative Study ; Female ; Human ; Korea/epidemiology ; Language ; Male ; Prevalence ; Questionnaires* ; Random Allocation ; Respiratory Sounds ; Saline Solution, Hypertonic/diagnostic use ; Sampling Studies ; Videotape Recording ; Writing

PURPOSE: Little data is currently available on the use of the impulse oscillometry system (IOS) parameter in analyzing the lung function of young children with cough-variant asthma (CVA) and classic asthma. The aims of this study were to evaluate the bronchial responsiveness between patients with CVA and those with classic asthma using dose-response slope and various cutoff values. METHODS: A methacholine challenge test and a pulmonary function test were performed in 43 children with classic asthma and 26 children with CVA using IOS, and the respiratory resistance (Rrs) and reactance (Xrs) were obtained. The bronchial responsiveness were assessed by provocative concentration causing an 80% fall from baseline in reactance at 5 Hz (PC80_Xrs5) and a 40% increase in resistance at 5 Hz (PC40_Rrs5) and calculating from the degree of dose-response slope (DRS) for airway resistance and reactance. RESULTS: There was no significant difference in base lung function between the two groups. However, the mean DRS_Xrs5 and the number who showed more than an 80% fall in reactance were significantly higher in classic asthma group than those in CVA group (P=0.040 and P=0.040, respectively). CONCLUSION: The use of DRS in oscillatory reactance at 5 Hz is useful for the differential diagnosis of classic asthma and CVA based on bronchial hyperresponsiveness.
Airway Resistance ; Asthma* ; Bronchial Hyperreactivity ; Child* ; Cough ; Diagnosis, Differential ; Humans ; Lung ; Methacholine Chloride ; Oscillometry ; Respiratory Function Tests

PURPOSE: This study aimed to evaluate the validity of chest auscultation and oxygen saturation measurement in the assessment of bronchial hyperreactivity to inhaled methacholine in preschool children who were thought to be asthmatic clinically. METHODS: Seventy-two children with a history of more than three wheezing episodes in the previous year were considered the asthma group and underwent methacholine bronchial challenges. Provocation concentration at wheezing (PCw), at 5% fall of oxygen saturation (PCSat), and at 50% increase in respiratory rate (PCRR) were determined in each subject. One hundred and eighteen children who have had less than two wheezing episodes in their life served as control group. RESULTS: The geometric means of PCw, PCSat, and PCRR of asthma group were significantly lower than those of the control group. The optimal cut-off level for PCw was 8 mg/mL, giving a sensitivity of 63% and a specificity of 78%. Corresponding values for PCSat and PCRR were 8 mg/mL (72%, 67%) and 16 mg/mL (49%, 86%), respectively. The area under the receiver operating characteristic (ROC) curve for PCw, PCSat, and PCRR were 0.80, 0.88, and 0.70 respectively. The discriminative capacity of PCSat as judged by ROC curve analysis exceed those of PCw and PCRR. CONCLUSION: These findings provide support for the use of chest auscultation and oxygen saturation measurement as a tool in the assessment of bronchial hyperreactivity. The cut-off level of 8 mg/mL for PCSat, owing to its highest discriminative capacity, may be useful for the diagnosis of asthma in preschool children.
Asthma ; Auscultation* ; Bronchial Hyperreactivity* ; Bronchial Provocation Tests ; Child ; Child, Preschool* ; Diagnosis ; Humans ; Methacholine Chloride ; Oxygen* ; Respiratory Rate ; Respiratory Sounds* ; ROC Curve ; Sensitivity and Specificity ; Thorax*

PURPOSE: To evaluate the HRCT findings and to correlate the findings with the results of a pulmonary function test (PFT) in patients with reactive airway dysfunction syndrome (RADS). MATERIALS AND METHODS: On March 2003, a fire at a boarding house of primary school soccer players caused a multiple casualty disaster. After 8 months, nine boys that presented with chronic cough and dyspnea were treated, and were subjected to follow-up evaluations. Eight patients underwent a chest radiograph, HRCT, and a PFT. Two patients with severe symptoms received extended follow-up after 1 year. Two radiologists retrospectively reviewed the chest radiographs and the follow-up HRCT scans. We correlated the HRCT findings with the results of the PFT. RESULTS: Six patients with an inhalation injury were diagnosed with RADS. On the chest radiographs, eight patients showed no abnormal findings. On an HRCT scan, four patients showed abnormal findings. The abnormal findings were mosaic air trapping (n = 4), bronchial wall thickening (n = 1), and parenchymal consolidation (n = 1). In all four patients that showed abnormal findings in the HRCT scan, abnormal results of the PFT were also seen. The two patients that received extended follow-up showed an improvement of the clinical symptoms, as seen by the PFT, and had a decreased extent and degree of mosaic air trapping, as seen on HRCT. CONCLUSION: An HRCT scan is an essential modality for the diagnosis and follow-up of patients with RADS. Both a full expiratory and inspiratory HRCT scan must be performed for an accurate diagnosis.
Bronchial Hyperreactivity ; Cough ; Diagnosis ; Disasters ; Dyspnea ; Fires ; Follow-Up Studies ; Humans ; Inhalation* ; Lung ; Radiography, Thoracic ; Respiratory Function Tests* ; Retrospective Studies ; Smoke Inhalation Injury ; Soccer ; Thorax*

BACKGROUND: Changes in airway mucosal osmolarity are an underlying mechanism of bronchoconstrictive responses to exercise and hypertonic saline (HS). The purpose of this study was to examine whether an osmotic challenge test using HS can predict exercise-induced bronchospasm (EIB) in asthma patients. METHODS: Thirty-six young male asthmatic patients underwent bronchial challenge tests based on 4.5% HS, exercise (> 24h later), and methacholine (MCh) at the Chonnam National University Hospital. The relationships between responses to HS and exercise, and between MCh and exercise were evaluated. RESULTS: The maximal fall in forced expiratory volume in one second following exercise was significantly higher in the HS-responders (n=19) than in the HS-nonresponders (n=17, 35.9+/-4.1% vs. 17.9+/-2.7%, p< 0.001), and there was a significant correlation between the severity of EIB and HS-airway hyperresponsiveness (AHR). When compared with the MCh-AHR test in terms of predicting EIB, the HS-AHR test showed higher specificity (71.4% vs. 42.9%), but a lower sensitivity (58.6% vs. 89.7%) and negative predictive value (29.4% vs. 50.0%). At the moderate AHR cutoff value, the MCh-AHR test had a specificity that was comparable with and predictive values that were higher than those of the HS-AHR test. CONCLUSIONS: The HS-AHR test was more specific than the MCh-AHR test, but was less sensitive and had a poorer negative predictive value, which in combination preclude the use of the HS-AHR test as a screening tool for EIB. The MCh-AHR test had a cutoff value for moderate AHR that may be more useful for predicting EIB in asthmatic patients.
Saline Solution, Hypertonic/*diagnostic use ; Predictive Value of Tests ; Methacholine Chloride/diagnostic use ; Male ; Humans ; Bronchoconstrictor Agents/diagnostic use ; Bronchial Provocation Tests/*methods ; Bronchial Hyperreactivity/*diagnosis ; Asthma, Exercise-Induced/*diagnosis ; Adult ; Adolescent

BACKGROUND: The airway muscles from allergen-sensitized animals in vitro show a heightened response to histamine, but not to carbachol. This study investigated whether the airway responsiveness to histamine in vivo is comparable to that of methacholine in human subjects with varying degrees of atopy. METHODS: One-hundred-and-sixty-eight consecutive adult asthma patients or volunteers underwent bronchoprovocation tests to both histamine and methacholine after determining their blood eosinophil counts, serum total IgE levels and skin test reactivity to 10 common aeroallergens. RESULTS: The responsiveness to histamine was significantly related to that to methacholine (r=0.609, p<0.001), but many individuals with a negative methacholine test response showed a positive response to histamine. The histamine-bronchial reactivity index (BRindex) was significantly higher than the methacholine-BRindex in subjects with a positive response to none (n=69, p<0.01) or only one (n=42, p<0.001) of histamine and methacholine, while there was no significant difference in the subjects with positive responses to both of them (n=57). The histamine-BRindex was significantly higher than the methacholine-BRindex in the subjects with mild histamine hyperresponsiveness (n=58, 1.28+/-0.01 vs. 1.20+/-0.02, respectively, p<0.001). Both histamine and methacholine responsiveness was significantly related to the atopy markers. However, the histamine-BRindex/methacholine-BRindex ratio of the atopics was not significantly different from that of the non-atopics. CONCLUSIONS: The airway responsiveness to histamine is comparable to that of methacholine in the subjects with positive responses to both histamine and methacholine, but the airway responsiveness to histamine is greater than that to methacholine in those subjects with mild airway hyperresponsiveness, regardless of atopy.
Adult ; Asthma/*physiopathology ; Bronchi/drug effects ; Bronchial Hyperreactivity/*diagnosis ; Bronchial Provocation Tests ; Bronchoconstrictor Agents/*pharmacology ; Eosinophils ; Female ; Histamine/*pharmacology ; Humans ; Immunoglobulin E/blood ; Male ; Methacholine Chloride/*pharmacology ; Severity of Illness Index ; Skin Tests

BACKGROUND/AIMS: We sought to increase our understanding of the rhinitis-asthma relationship and improve strategies for the treatment of patients with these diseases. The aim of this study was to identify a connection between upper airway inflammation and lower airway responsiveness. METHODS: We counted eosinophils on nasal smears, and performed spirometry, allergic skin tests, and methacholine challenge tests in 308 schoolchildren plus a questionnaire on respiratory symptoms. The methacholine concentration causing a 20% fall in forced expiratory volume in 1 second (PC20 < 25 mg/mL) was used as the threshold of bronchial hyperresponsiveness (BHR). RESULTS: In total, 26% of subjects had positive nasal eosinophils on a smear, and 46.2% of subjects had BHR at < 25 mg/mL methacholine PC20. Nasal symptoms were higher in subjects with than without nasal eosinophils (p = 0.012). Asthma symptoms did not differ between subjects with and without nasal eosinophils. Nasal eosinophils were higher in subjects with atopy than those without (p = 0.006), and there was no difference in PC20 methacholine according to atopy (15.5 +/- 1.07 vs. 17.5 +/- 0.62; p > 0.05). No difference in BHR was detected when comparing subjects with and without nasal eosinophils. There were significant differences in the PC20 between subjects with greater than 50% nasal eosinophils and without nasal eosinophils (11.01 +/- 2.92 mg/mL vs. 17.38 +/- 0.61 mg/mL; p < 0.001). CONCLUSIONS: These findings demonstrated that nasal eosinophilic inflammation might contribute to lower airway responsiveness in schoolchildren, based on an epidemiological survey.
Adolescent ; Age Distribution ; Age Factors ; Asthma/diagnosis/*epidemiology/physiopathology ; Bronchial Hyperreactivity/diagnosis/*enzymology/physiopathology ; Bronchial Provocation Tests ; Child ; Eosinophilia/diagnosis/*epidemiology/immunology ; Eosinophils/immunology ; Female ; Health Surveys ; Humans ; Intradermal Tests ; Leukocyte Count ; Lung/*physiopathology ; Male ; Nasal Mucosa/*immunology ; Republic of Korea/epidemiology ; Rhinitis/diagnosis/*epidemiology/immunology ; Spirometry ; Surveys and Questionnaires

BACKGROUND: A US Food and Drug Administration (FDA)-approved drug methacholine chloride (Provocholine®) was recently introduced to Korea where it is now widely used in clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine in 7-year-old children. METHODS: Six hundred and thirty-three children from the Panel Study on Korean Children who visited 16 regional hospitals were evaluated. Skin prick tests, spirometry and bronchial provocation tests for Provocholine as well as a detailed history and physical examinations were performed. The bronchial provocation test was reliably performed on 559 of these children. RESULTS: The prevalence of ever-diagnosed asthma via medical records was 7.7%, and that of current asthma (wheezy episode in the last 12 months + diagnosed asthma by physicians) was 3.2%. The prevalence of BHR to Provocholine was 17.2% and 25.8%, respectively, for a PC20 < 8 and < 16 mg/mL. The risk factors for BHR (PC20 < 16 mg/mL) were atopic dermatitis diagnosis and current dog ownership, whereas those for current asthma were allergy rhinitis diagnosis, a history of bronchiolitis before the age of 3, recent use of analgesics/antipyretics and maternal history of asthma. The BHR prevalence trend showed an increase along with the increased immunoglobulin E (IgE) quartile. The cutoff value of PC20 for the diagnosis of current asthma in children at age 7 was 5.8 mg/mL (sensitivity: 47.1%, specificity: 87.4%). CONCLUSIONS: BHR to Provocholine (PC20 < 8 mg/mL) was observed in 17.2% of 7-year-olds children from the general population and the cutoff value of PC20 for the diagnosis of current asthma was 5.8 mg/mL in this age group. The risk factors for BHR and current asthma showed discrepancies suggesting different underlying mechanisms. Bronchial provocation testing with Provocholine will be a useful clinical tool in the future.
Animals ; Asthma ; Bronchial Hyperreactivity ; Bronchial Provocation Tests ; Bronchiolitis ; Child* ; Dermatitis, Atopic ; Diagnosis ; Dogs ; Humans ; Hypersensitivity ; Immunoglobulin E ; Immunoglobulins ; Korea ; Medical Records ; Methacholine Chloride* ; Ownership ; Physical Examination ; Prevalence* ; Rhinitis ; Risk Factors* ; ROC Curve ; Sensitivity and Specificity ; Skin ; Spirometry ; United States Food and Drug Administration