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Singh S. Bronchial challenge test in patients with a history suggestive of bronchial asthma with normal spirometric studies. Med J Armed Forces India 2020; 77:82-85. [PMID: 33487871 DOI: 10.1016/j.mjafi.2020.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 05/11/2020] [Indexed: 10/23/2022] Open
Abstract
Background Bronchial hyper-responsiveness (BHR) is the hallmark of bronchial asthma, characterized by clinical features of cough, wheeze, breathlessness and chest tightness which are confirmed by spirometry showing obstructive pattern and reversibility to bronchodilators. In individuals having features of bronchial asthma but normal spirometry, demonstration of BHR with bronchial challenge test (direct or indirect) confirms/ rules out the diagnosis. The aim of this study was to assess BHR in patients (methacholine challenge) with a history suggestive of bronchial asthma but normal spirometry and its role in diagnosis of bronchial asthma. Methods This study was conducted at tertiary care respiratory center. Patients having clinical features of bronchial asthma but spirometry not confirming obstructive disorder and or reversibility were included in the study. After written consent, methacholine challenge test with methacholine chloride and exercise spirometry was done in all patients as per the American Thoracic Society protocol. Results A total of 50 (n) patients were included in the study. Among them, 42 patients had clinical features suggestive of bronchial asthma but having normal spirometry and eight patients were diagnosed as they had bronchial asthma in the past but asymptomatic and off drugs were included in the study. At PC20 4mg/ml 32 (64%) patients had a positive test, 28(66%) symptomatic patients and four (50%) asymptomatic asthmatics. There were no significant side effects with methacholine test. Conclusion Airway hyper-responsiveness is an important aspect of bronchial asthma and its demonstration with bronchial challenge (direct and indirect) test is an important diagnostic tool. Methacholine challenge test is a safe procedure to perform under supervision.
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Affiliation(s)
- Sarvinder Singh
- Consultant (Med & Resp Med), Army Hospital (R&R), Delhi Cantt 110010, India
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Lim KH, Kim MH, Yang MS, Song WJ, Jung JW, Lee J, Suh DI, Shin YS, Kwon JW, Kim SH, Kim SH, Lee BJ, Cho SH. The KAAACI Standardization Committee Report on the procedure and application of the bronchial provocation tests. ALLERGY ASTHMA & RESPIRATORY DISEASE 2018. [DOI: 10.4168/aard.2018.6.1.14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Kyung-Hwan Lim
- Department of Internal Medicine, Armed Forces Capital Hospital, Seongnam, Korea
| | - Min-Hye Kim
- Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea
| | - Min-Suk Yang
- Department of Internal Medicine, Seoul Metropolitan Government - Seoul National University Boramae Medical Center, Seoul, Korea
| | - Woo-Jung Song
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Jae-Woo Jung
- Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea
| | - Jeongmin Lee
- Department of Pediatrics, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Dong In Suh
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
| | - Yoo Seob Shin
- Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea
| | - Jae-Woo Kwon
- Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Sae-Hoon Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Sang-Heon Kim
- Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea
| | - Byung-Jae Lee
- Division of Allergy, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sang-Heon Cho
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
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Teodorescu M, Broytman O, Curran-Everett D, Sorkness RL, Crisafi G, Bleecker ER, Erzurum S, Gaston BM, Wenzel SE, Jarjour NN. Obstructive Sleep Apnea Risk, Asthma Burden, and Lower Airway Inflammation in Adults in the Severe Asthma Research Program (SARP) II. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2015; 3:566-75.e1. [PMID: 26004304 DOI: 10.1016/j.jaip.2015.04.002] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 03/04/2015] [Accepted: 04/02/2015] [Indexed: 11/25/2022]
Abstract
BACKGROUND Obstructive sleep apnea (OSA) may worsen asthma, but large studies are lacking and the underlying mechanisms are unknown. OBJECTIVE The objective of this study was to determine the prevalence of OSA risk among patients with asthma of different severity compared with normal controls (NC), and among asthmatics, to test the relationship of OSA risk with asthma burden and airway inflammation. METHODS Subjects with severe (SA, n = 94) and nonsevere asthma (NSA, n = 161), and NC (n = 146) were recruited in an add-on substudy, to the observational Severe Asthma Research Program (SARP) II; subjects completed sleep quality, sleepiness and OSA risk (Sleep Apnea scale of the Sleep Disorders Questionnaire [SA-SDQ]) questionnaires, and clinical assessments. Sputum was induced in a subset of asthmatics. RESULTS Relative to NC, despite similar sleep duration, the subjects with SA and NSA had worse sleep quality, were sleepier, and had higher SA-SDQ scores. Among asthmatics, higher SA-SDQ was associated with increased asthma symptoms, β-agonist use, health care utilization, and worse asthma quality of life. A significant association of SA-SDQ with sputum polymorphonuclear cells% was noted: each increase in SA-SDQ by its standard deviation (6.85 units) was associated with a rise in % sputum neutrophils of 7.78 (95% CI 2.33-13.22, P = .0006), independent of obesity and other confounders. CONCLUSIONS OSA symptoms are more prevalent among asthmatics, in whom they are associated with higher disease burden. OSA risk is associated with a neutrophilic airway inflammation in asthma, which suggests that OSA may be an important contributor to the neutrophilic asthma. Further studies are necessary to confirm these findings and better understand the mechanistic underpinnings of this relationship.
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Affiliation(s)
- Mihaela Teodorescu
- James B. Skatrud Pulmonary/Sleep Research Laboratory, Medical Service, William S. Middleton Memorial Veterans Hospital, Madison, Wis; Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis; Center for Sleep Medicine and Sleep Research/Wisconsin Sleep, University of Wisconsin School of Medicine and Public Health, Madison, Wis.
| | - Oleg Broytman
- James B. Skatrud Pulmonary/Sleep Research Laboratory, Medical Service, William S. Middleton Memorial Veterans Hospital, Madison, Wis; Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis
| | - Douglas Curran-Everett
- Division of Biostatistics and Bioinformatics, National Jewish Health, Denver, Colo; Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Denver, Denver, Colo
| | - Ronald L Sorkness
- Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis
| | - Gina Crisafi
- Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis
| | - Eugene R Bleecker
- Department of Medicine, Wake Forest University School of Medicine, Winston-Salem, NC
| | - Serpil Erzurum
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Benjamin M Gaston
- Division of Respiratory Medicine, Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Va
| | - Sally E Wenzel
- Asthma Institute, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pa
| | - Nizar N Jarjour
- Division of Allergy, Pulmonary and Critical Care Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wis
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The challenge of objective confirmation of asthma diagnosis in primary care. NPJ Prim Care Respir Med 2014; 24:14032. [PMID: 25056516 PMCID: PMC4373401 DOI: 10.1038/npjpcrm.2014.32] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 01/13/2014] [Accepted: 01/21/2014] [Indexed: 11/30/2022] Open
Abstract
Asthma represents one of the most common chronic conditions encountered in primary care and diagnosis should be confirmed objectively with the demonstration of variable airflow obstruction. As many asthmatics have normal lung function at the time of clinical presentation, objective confirmation of airflow limitation may be challenging. Fluctuations in airflow obstruction can be documented with simple office spirometry after bronchodilator challenge, home monitoring of peak expiratory flow and bronchoconstriction induced by spasmogens such as methacholine. We present a case highlighting the challenge of objective confirmation of asthma diagnosis in primary care and provide a critical review of the diagnostic approaches highlighted above. Our aim is to provide a pragmatic interpretation of the available literature with a view to assisting clinicians in selecting the diagnostic test best suited for individualised patient encounters.
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5
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Cabana MD, Kunselman SJ, Nyenhuis SM, Wechsler ME. Researching asthma across the ages: insights from the National Heart, Lung, and Blood Institute's Asthma Network. J Allergy Clin Immunol 2014; 133:27-33. [PMID: 24369796 PMCID: PMC3901784 DOI: 10.1016/j.jaci.2013.10.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 10/14/2013] [Accepted: 10/15/2013] [Indexed: 11/24/2022]
Abstract
Clinical asthma studies across different age groups (ie, cross-age studies) can potentially offer insight into the similarities, differences, and relationships between childhood and adult asthma. The National Institutes of Health's Asthma Research Network (AsthmaNet) is unique and innovative in that it has merged pediatric and adult asthma research into a single clinical research network. This combination enhances scientific exchange between pediatric and adult asthma investigators and encourages the application of cross-age studies that involve participants from multiple age groups who are generally not studied together. The experience from AsthmaNet in the development of cross-age protocols highlights some of the issues in the evaluation of cross-age research in asthma. The aim of this review is to summarize these challenges, including the selection of parallel cross-age clinical interventions, identification of appropriate controls, measurement of meaningful clinical outcomes, and various ethical and logistic issues.
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Affiliation(s)
- Michael D Cabana
- Departments of Pediatrics, Epidemiology, and Biostatistics and the Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, Calif.
| | | | - Sharmilee M Nyenhuis
- Division of Pulmonary, Critical Care, Sleep and Allergy, University of Illinois Hospital and Health Sciences System, Chicago, Ill
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6
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Abstract
The development and clinical application of lung function tests have a long history, and the various components of lung function tests provide very important tools for the clinical evaluation of respiratory health and disease. Spirometry, measurement of the diffusion factor, bronchial provocation tests and forced oscillation techniques have found diverse clinical applications in the diagnosis and monitoring of respiratory diseases, such as chronic obstructive pulmonary disease, interstitial lung diseases and asthma. However, there are some practical issues to be resolved, including the establishment of reference values for individual test parameters and the roles of these tests in preoperative risk assessment and pulmonary rehabilitation. Novel measurements, including negative expiratory pressure, the fraction of exhaled nitric oxide and analysis of exhaled breath condensate, may provide new insights into physiological abnormalities or airway inflammation in respiratory diseases, but their clinical applications need to be further evaluated. The clinical application of lung function tests continues to face challenges, which may be overcome by further improvement of conventional techniques for lung function testing and further specification of new testing techniques.
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Affiliation(s)
- Bin-Miao Liang
- Department of Respiratory Medicine, West China Hospital of Sichuan University, Sichuan, China
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7
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Tepper RS, Wise RS, Covar R, Irvin CG, Kercsmar CM, Kraft M, Liu MC, O'Connor GT, Peters SP, Sorkness R, Togias A. Asthma outcomes: pulmonary physiology. J Allergy Clin Immunol 2012; 129:S65-87. [PMID: 22386510 DOI: 10.1016/j.jaci.2011.12.986] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 12/23/2011] [Indexed: 10/28/2022]
Abstract
BACKGROUND Outcomes of pulmonary physiology have a central place in asthma clinical research. OBJECTIVE At the request of National Institutes of Health (NIH) institutes and other federal agencies, an expert group was convened to provide recommendations on the use of pulmonary function measures as asthma outcomes that should be assessed in a standardized fashion in future asthma clinical trials and studies to allow for cross-study comparisons. METHODS Our subcommittee conducted a comprehensive search of PubMed to identify studies that focused on the validation of various airway response tests used in asthma clinical research. The subcommittee classified the instruments as core (to be required in future studies), supplemental (to be used according to study aims and in a standardized fashion), or emerging (requiring validation and standardization). This work was discussed at an NIH-organized workshop in March 2010 and finalized in September 2011. RESULTS A list of pulmonary physiology outcomes that applies to both adults and children older than 6 years was created. These outcomes were then categorized into core, supplemental, and emerging. Spirometric outcomes (FEV(1), forced vital capacity, and FEV(1)/forced vital capacity ratio) are proposed as core outcomes for study population characterization, for observational studies, and for prospective clinical trials. Bronchodilator reversibility and prebronchodilator and postbronchodilator FEV(1) also are core outcomes for study population characterization and observational studies. CONCLUSIONS The subcommittee considers pulmonary physiology outcomes of central importance in asthma and proposes spirometric outcomes as core outcomes for all future NIH-initiated asthma clinical research.
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8
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Craig T, Quinn L. Asthma Clinical Research Network: lessons learned. ACTA ACUST UNITED AC 2012; 78:671-82. [PMID: 21913198 DOI: 10.1002/msj.20282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The Asthma Clinical Research Network was created by the National Heart, Lung, and Blood Institute to improve public health by rapidly evaluating novel and existing therapeutic approaches to asthma. The multicenter clinical research network has greatly contributed to the healthcare community's understanding of asthma by conducting clinical trials independent of the pharmaceutical industry. The following manuscript reviews the experimental design and major findings of noteworthy studies performed in this network. All of the network's publications were reviewed, and 19 were selected for summary. As shown in these publications, the research performed by the Asthma Clinical Research Network has produced significant data with important implications that should impact the way the healthcare community treats asthma at the present time.
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Busse PJ, Kilaru K. Complexities of diagnosis and treatment of allergic respiratory disease in the elderly. Drugs Aging 2009; 26:1-22. [PMID: 19102511 DOI: 10.2165/0002512-200926010-00001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Atopic diseases such as rhinitis and asthma are relatively common in children and young adults. However, many patients aged >65 years are also affected by these disorders. Indeed, the literature suggests that between 3-12% and 4-13% of individuals in this age range have allergic rhinitis and asthma, respectively. However, these numbers are most likely underestimates because atopic diseases are frequently not considered in older patients. The diagnosis of both allergic rhinitis and asthma in older patients is more difficult than in younger patients because of a wide differential diagnosis of other diseases that can produce similar symptoms and must be excluded. Furthermore, treatment of these disorders is complicated by the potential for drug interactions, concern about the adverse effects of medications, in particular corticosteroids, and the lack of drug trials specifically targeting treatment of older patients with allergic rhinitis and asthma.
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Affiliation(s)
- Paula J Busse
- Division of Clinical Immunology, The Mount Sinai School of Medicine, New York, New York, USA.
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10
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Lloris Bayo A, Perpiñá Tordera M, Martínez Pérez E, Macián Gisbert V. Aportaciones del óxido nítrico exhalado a los procedimientos abreviados de las pruebas de provocación bronquial. Arch Bronconeumol 2008. [DOI: 10.1016/s0300-2896(08)72102-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Birnbaum S, Barreiro TJ. Methacholine challenge testing: identifying its diagnostic role, testing, coding, and reimbursement. Chest 2007; 131:1932-5. [PMID: 17565027 DOI: 10.1378/chest.06-1385] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Methacholine challenge testing (MCT), also sometimes described as bronchoprovocation testing, is widely performed for both research and diagnostic purposes. MCT is clinically useful when the patient presents with a history of symptoms suggesting asthma, but spirometry findings are normal. Typically, MCT is performed in a pulmonary function laboratory, a clinic, or a physician's office. MCT requires time, effort, and understanding. Two standard testing regimes are identified along with proper coding and reimbursement methodologies.
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Affiliation(s)
- Sam Birnbaum
- Division of Pulmonary and Critical Care Medicine, Northeastern Ohio Univeristies College of Medicine, Ohio University College of Osteopathic Medicine, OH, USA.
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12
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Hagmolen of ten Have W, van den Berg NJ, van der Palen J, Bindels PJE, van Aalderen WMC. Validation of a single concentration methacholine inhalation provocation test (SCIPT) in children. J Asthma 2005; 42:419-23. [PMID: 16293536 DOI: 10.1081/jas-67934] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A new method to assess bronchial hyperresponsiveness (BHR) using a single concentration methacholine has already been validated in adults with asthma. Because the geometrical dimensions of the airways in children are different, the results from studies in adults cannot be extrapolated to children. In this study, we validated the single concentration methacholine inhalation provocation test (SCIPT) in children. Twenty-two children performed three methacholine inhalation challenge tests in random order. Two challenges were performed according to the SCIPT: doubling doses (0.03-1.8 mg; maximal cumulated dose 3.6 mg) were administered with an Aerosol Provocation System (Masterscope, Jaeger). The third challenge was performed according to a standard dosimeter method (SDM): doubling doses (0.002-1.8 mg; maximal cumulative dose 3.5 mg) were administered with a DeVillbiss 646 nebulizer. The degree of BHR is expressed as a PD20. A difference of < 1.5 dose step was assumed to be due to intraindividual variation. We found an intraclass correlation of 0.91 between both tests according to the SCIPT and of 0.80 between the SCIPT and SDM. We found, according to the method of Bland and Altman, good agreement when comparing these two challenge tests. The single concentration inhalation provocation test is reproducible and shows good agreement with a standard dosimeter method to test bronchial responsiveness in children.
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Busse WW, Wanner A, Adams K, Reynolds HY, Castro M, Chowdhury B, Kraft M, Levine RJ, Peters SP, Sullivan EJ. Investigative bronchoprovocation and bronchoscopy in airway diseases. Am J Respir Crit Care Med 2005; 172:807-16. [PMID: 16020805 PMCID: PMC2718402 DOI: 10.1164/rccm.200407-966ws] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Basic and clinical research strategies used for many lung diseases have depended on volunteer subjects undergoing bronchoscopy to establish access to the airways to collect biological specimens and tissue, perhaps with added bronchoprovocation in asthma syndromes. These procedures have yielded a wealth of important scientific information. Since the last critical review more than a decade ago, some of the techniques and applications have changed, and untoward events have occurred, raising safety concerns and increasing institutional review scrutiny. OBJECTIVES AND METHODS To reappraise these investigational methods in the context of current knowledge, the National Heart, Lung, and Blood Institute and the National Institute of Allergy and Infectious Diseases of the National Institutes of Health convened a working group to review these procedures used for airway disease research, emphasizing asthma and chronic obstructive pulmonary disease. MAIN RESULTS The group reaffirmed the scientific importance of investigative bronchoscopy and bronchoprovocation, even as less invasive technologies evolve. The group also considered the safety of bronchoscopy and bronchoprovocation with methacholine and antigen to be acceptable for volunteer subjects and patients, but stressed the need to monitor this closely and to emphasize proper training of participating medical research personnel. Issues were raised about vulnerable volunteers, especially children who need surrogates for informed consent. CONCLUSION This review of investigative bronchoscopy and bronchoprovocation could serve as the basis for future guidelines for the use of these procedures in the United States.
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Abstract
Bronchoprovocation testing has been performed for more than 50 years. Challenge testing with nonselective agents has been used widely for the assessment of airflow limitation in patients, and has been used in the research setting to better characterize the pathophysiology of bronchial responsiveness. Based on this large body of literature, detailed guidelines are now available to allow for standardization of testing methodology. Such standardization is critical to achieve safe, accurate, and reproducible test results that may be interpreted meaningfully. Currently, bronchoprovocation testing with direct-acting stimuli such as methacholine is used most frequently in the clinical arena, but, in recent years, considerable interest has been developing in the use of indirect stimuli. (57) It now is recognized that bronchial hyperresponsiveness to indirect stimuli (e.g., exercise, cold air, and AMP) is highly specific for asthma and may have greater clinical relevance than does responsiveness to direct stimuli. (8) As a result, testing with indirect agents may become employed more widely in the future.
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Affiliation(s)
- H Cain
- Pulmonary Function Laboratory, VA Connecticut Healthcare System, West Haven, Connecticut, USA
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15
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Mauger EA, Mauger DT, Fish JE, Chinchilli VM, Israel E. Summarizing methacholine challenges in clinical research. CONTROLLED CLINICAL TRIALS 2001; 22:244S-51S. [PMID: 11728628 DOI: 10.1016/s0197-2456(01)00159-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In clinical trials in asthma, airway reactivity is commonly assessed by performing a methacholine challenge. Airway reactivity is thought to vary in proportion to asthma severity, and methacholine causes the airways of asthma subjects to constrict, thus lowering forced expiratory volume in 1 second (FEV(1)). A dose-response curve is obtained for each subject who meets standardized eligibility requirements to proceed with a methacholine challenge. When data from a methacholine challenge are used as an outcome variable in analysis, a univariate measure called the PC(20), the concentration of methacholine needed to produce a 20% fall in FEV(1) from baseline, is typically used to summarize the dose-response curve. Questions that arise regarding data generated from the methacholine challenge include: how to express data that do not yield a PC(20) value; whether PC(20) actually represents the best way to capture airway activity as expressed in a methacholine challenge; and whether the baseline FEV(1) is defined appropriately in calculation of PC(20). The impact of these issues on the statistical analysis of methacholine challenge data is described in this article. Some adjustments to the usual estimates of PC(20) and parametric modeling of the entire dose-response curve are proposed as alternatives that address some of the shortcomings of PC(20).
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Affiliation(s)
- E A Mauger
- Department of Health Evaluation Sciences, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA.
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16
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Buck H, Parry-Billings M. Discriminating measures of bronchodilator drug efficacy and potency. Br J Clin Pharmacol 2001; 52:245-53. [PMID: 11560556 PMCID: PMC2014546 DOI: 10.1046/j.0306-5251.2001.01450.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2000] [Accepted: 05/04/2001] [Indexed: 11/20/2022] Open
Affiliation(s)
- H Buck
- Innovata Biomed Limited, The Ziggurat, Grosvenor Road, St Albans, Hertfordshire AL1 3HW, UK
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17
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Wanger JS, Ikle DN, Irvin CG. Airway responses to a diluent used in the methacholine challenge test. Ann Allergy Asthma Immunol 2001; 86:277-82. [PMID: 11289324 DOI: 10.1016/s1081-1206(10)63298-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Inhalation of diluent is often used in performing methacholine challenge tests, but its elimination has been suggested because marked falls in FEV1 after diluent inhalation have not been documented and performing this step is time-consuming. OBJECTIVE We investigated the frequency and magnitude of response to the inhalation of diluent, and if there were any systematic effects in determining the PC20 using the baseline and postdiluent spirometric measurements. METHODS All methacholine challenges performed during a 6-year period (N = 3,902) were reviewed retrospectively. RESULTS The maximum increase and decrease in FEV1 and FVC from baseline were 56.3% and -41.4%, respectively, and 61.7% and -40.3%, respectively. The mean absolute changes from baseline in FEV1 and FVC were -0.018 L and -0.026 L, respectively. There was a highly significant correlation (r2 = 0.96; P < .0001) between the PC20 baseline and PC20 postdiluent values, and a mean difference of 0.041 mg/mL (P < .0001), with the PC20 postdiluent being higher. CONCLUSIONS These data do not provide strong evidence to support either using or eliminating the diluent stage. It is clear that there are frequent and sometimes large changes in FVC and FEV1 after the inhalation of diluent containing phenol and sodium bicarbonate buffer. If a laboratory intends to report changes in airway function qualitatively (ie, positive or negative), the diluent stage may not be necessary. However, if a laboratory intends to report bronchial challenge data from inhaling methacholine in a quantitative fashion and report a continuous variable such as PC20, a diluent stage is recommended.
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Affiliation(s)
- J S Wanger
- Pharmaceutical Research Associates Inc., Lenexa, Kansas, USA.
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18
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Zeiger RS, Schatz M. Effect of allergist intervention on patient-centered and societal outcomes: allergists as leaders, innovators, and educators. J Allergy Clin Immunol 2000; 106:995-1018. [PMID: 11112881 DOI: 10.1067/mai.2000.110921] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Atopic disorders, which afflict millions of Americans and hundreds of millions worldwide, are at epidemic levels with concomitant increases in morbidity and mortality. Environmental and lifestyle changes over the past three to five decades are proposed causes for this pandemic and as such present major burdens to reverse. The scope of allergy practice bridges directly on this challenge. Allergy as a specialty is a major leader in developing effective strategies to confront this epidemic. Allergists have made major contributions to the understanding of the risk factors, immunology, pathophysiology, immunomodulation, and prevention of atopic and immunologic disorders. Allergist epidemiologists and clinicians have helped develop and implement national and international guidelines in the recognition, management, and prevention of asthma and rhinitis. Allergist clinical researchers are active in (1) outcomes research that demonstrates convincingly the value of allergy as a specialty in asthma, allergic rhinitis, anaphylaxis, drug and food allergy, and other atopic disorders, (2) National Institutes of Health clinical trials that will form the basis for the future treatment of asthma and allergic disease, and (3) pharmaceutical trials that evaluate new, effective, and safe medication to treat atopic disease. Allergist educators, comprising academic and practicing allergists, supported by allied health professionals, national associations, and affiliated lay organizations, provide comprehensive education to fellows, residents, colleague physicians, media, the public, and patients. Documentation of the value of allergists in improving patient-centered and societal outcomes in their core domain, allergy, is the appropriate final topic contribution in the important series "New millennium: The conquest of allergy."
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Affiliation(s)
- R S Zeiger
- Department of Allergy-Immunology, Kaiser Permanente Medical Center, University of California, San Diego 92111, USA
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Crapo RO, Casaburi R, Coates AL, Enright PL, Hankinson JL, Irvin CG, MacIntyre NR, McKay RT, Wanger JS, Anderson SD, Cockcroft DW, Fish JE, Sterk PJ. Guidelines for methacholine and exercise challenge testing-1999. This official statement of the American Thoracic Society was adopted by the ATS Board of Directors, July 1999. Am J Respir Crit Care Med 2000; 161:309-29. [PMID: 10619836 DOI: 10.1164/ajrccm.161.1.ats11-99] [Citation(s) in RCA: 1462] [Impact Index Per Article: 60.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Banik AN, Holgate ST. Problems and progress in measuring methacholine bronchial reactivity. Clin Exp Allergy 1998; 28 Suppl 1:15-9; discussion 32-6. [PMID: 9641585 DOI: 10.1046/j.1365-2222.1998.0280s1015.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- A N Banik
- University Medicine, Southampton University, UK
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