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Pneumoftiziologia : Revista Societatii... 1994The inhalational histamine and metacholine test is a standard procedure to estimate the degree of bronchial reactivity. During the last 10 years the method of... (Review)
Review
The inhalational histamine and metacholine test is a standard procedure to estimate the degree of bronchial reactivity. During the last 10 years the method of continuously generated aerosol inhalation compels recognition. The test consists in the inhalation during 2 minutes, every 5 minutes of a double dosage of drug followed by measurement of MEVS after each step. Thus the dosage response curve is set up. The concentration of the necessary drug dosage for decreasing with 20% of MEVS (PC20 or PD20) are accepted as indices for bronchial reactivity. The method is indicated in cases suspected for atypical bronchial asthma, professional asthma and drug research. The technical and subjective factors interfering the measurements should be taken into account and analysed in order to ensure reproducibility and comparability of the method.
Topics: Administration, Inhalation; Bronchial Hyperreactivity; Bronchial Provocation Tests; Histamine; Humans; Methacholine Chloride; Reproducibility of Results
PubMed: 7734984
DOI: No ID Found -
Chest Aug 2002
Topics: Algorithms; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoconstrictor Agents; Humans; Methacholine Chloride; Time Factors
PubMed: 12171865
DOI: 10.1378/chest.122.2.752 -
American Journal of Respiratory and... May 1999
Topics: Bronchoconstrictor Agents; Dose-Response Relationship, Drug; Humans; Methacholine Chloride; Reference Values
PubMed: 10375256
DOI: 10.1164/ajrccm.159.5.15961 -
Annals of Allergy, Asthma & Immunology... May 2013The effect of particle size on methacholine provocation concentration causing a decrease in forced expiratory volume of 1 second (FEV1) of 20% (PC20) is debatable. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The effect of particle size on methacholine provocation concentration causing a decrease in forced expiratory volume of 1 second (FEV1) of 20% (PC20) is debatable.
OBJECTIVE
To evaluate the functional effects of 3 different particle size nebulizers on methacholine PC20.
METHODS
Participants were randomly assigned to have 3 methacholine challenges on 3 separate days. Nebulizer mass median aerodynamic diameter (MMAD) was provided by manufacturers. The Wright nebulizer (MMAD, 1.0 μm), Aeroneb (MMAD, 3 μm), and Aeroneb (MMAD, 5 μm) were calibrated, and the nebulizer outputs were calculated to administer 0.26 mL of methacholine over 120, 112, and 83 seconds, respectively. After each inhalation, spirometry was performed and the test was terminated when the PC20 was achieved.
RESULTS
Eight nonsmoking patients with mild asthma (4 male and 4 female) completed the study. The mean (SD) age was 25 (13.9) years, and the mean (SD) baseline FEV1 was 88% (11.3%). Patients using the Aeroneb (MMAD, 5 μm) nebulizer had the lowest PC20 (bronchoconstricted at lowest methacholine concentration), with a PC20 geometric mean of 0.62 mg/mL compared with patients using the Aeroneb (MMAD, 3.0 μm), who had a PC20 of 1.76 mg/mL, and patients using the Wright nebulizer (MMAD, 1.0 μm), who had a PC20 of 6.32 mg/mL. There was a significant difference in PC20 across all particle sizes (P < .001). The pairwise differences revealed a P < .001 between 3 μm and 1 μm and between 5 μm and 1 μm and a P = .008 between 5 μm and 3 μm.
CONCLUSION
Our results reveal a variability in methacholine PC20 using 3 different nebulizers, despite adjusting the nebulizers' outputs. Our results are consistent with the previous reports, which recommended using larger particle size nebulizers in the assessment of airway hyperresponsiveness in asthma.
TRIAL REGISTRATION
clinicaltrials.gov Identifier: NCT00529477.
Topics: Adolescent; Adult; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoconstrictor Agents; Cross-Over Studies; Female; Humans; Male; Methacholine Chloride; Middle Aged; Particle Size; Spirometry; Young Adult
PubMed: 23622007
DOI: 10.1016/j.anai.2013.02.014 -
American Journal of Physiology.... Oct 2015Acetylcholine released from cholinergic nerves is a key neurotransmitter contributing to heat stress-induced cutaneous vasodilation and sweating. Given that sympathetic...
Acetylcholine released from cholinergic nerves is a key neurotransmitter contributing to heat stress-induced cutaneous vasodilation and sweating. Given that sympathetic cholinergic nerves also release ATP, ATP may play an important role in modulating cholinergic cutaneous vasodilation and sweating. However, the pattern of response may differ between males and females given reports of sex-related differences in the peripheral mechanisms governing these heat loss responses. Cutaneous vascular conductance (CVC, laser-Doppler perfusion units/mean arterial pressure) and sweat rate (ventilated capsule) were evaluated in 17 young adults (8 males, 9 females) at four intradermal microdialysis skin sites continuously perfused with: 1) lactated Ringer (Control), 2) 0.3 mM ATP, 3) 3 mM ATP, or 4) 30 mM ATP. At all skin sites, methacholine was coadministered in a concentration-dependent manner (0.0125, 0.25, 5, 100, 2,000 mM, each for 25 min). In both males and females, CVC was elevated with the lone infusion of 30 mM ATP (both P < 0.05), but not with 0.3 and 3 mM ATP compared with control (all P >0.27). However, 0.3 mM ATP induced a greater increase in CVC compared with control in response to 100 mM methacholine infusion in males (P < 0.05). In females, 0.3 mM ATP infusion resulted in a lower concentration of methacholine required to elicit a half-maximal response (EC50) (P < 0.05). In both males and females, methacholine-induced sweating was unaffected by any concentration of ATP (all P > 0.44). We demonstrate that ATP enhances cholinergic cutaneous vasodilation albeit the pattern of response differs between males and females. Furthermore, we show that ATP does not modulate cholinergic sweating.
Topics: Adenosine Triphosphate; Female; Humans; Injections, Intradermal; Male; Methacholine Chloride; Skin; Sweating; Urine; Vasodilation; Young Adult
PubMed: 26290105
DOI: 10.1152/ajpregu.00261.2015 -
Clinical Physiology and Functional... Sep 2018Recent technical recommendations on bronchial challenge testing aim at standardized assessment of provocative dose of causing 20% decrease in FEV1 (PD20). The aim of... (Comparative Study)
Comparative Study
Recent technical recommendations on bronchial challenge testing aim at standardized assessment of provocative dose of causing 20% decrease in FEV1 (PD20). The aim of this study was to investigate the effect of mode of nebulization on the output of a computerized dosimeter (APS) and to compare PD20 obtained by two different dosimetric systems in vivo. The output of the APS system was tested during continuous nebulization, and using simulated breaths, for intermittent actuations with four different durations. Using output data, a modified methacholine challenge protocol was applied for APS and compared with a standard set-up using Spira dosimeter in 14 asthmatic patients attending duplicate methacholine challenges using both systems, within median (range) 3 (1-6) days apart. The calculated output (mg min ) with all the intermittent mode settings was significantly higher (P<0·001) than in the continuous mode, and in the intermittent mode, the output was dependent of the pulse duration. The PD20 values assessed with the APS and Spira systems were significantly correlated (r = 0·69; P<0·007), without systematic difference in the geometric means (P = 0·10). A moderate to good agreement was found for assessment of significant hyperresponsiveness. The results suggest that in dosimetric systems for bronchial challenge tests, the output of the nebulizer is dependent on the mode of nebulization, and this should be considered when standardizing the dose between devices and protocols. As long as the delivered dose is determined for the specified nebulization mode of the protocol, it may be possible to obtain comparable results between different devices.
Topics: Administration, Inhalation; Asthma; Bronchial Provocation Tests; Bronchoconstrictor Agents; Drug Dosage Calculations; Equipment Design; Forced Expiratory Volume; Humans; Lung; Methacholine Chloride; Nebulizers and Vaporizers; Predictive Value of Tests; Reproducibility of Results
PubMed: 29345046
DOI: 10.1111/cpf.12498 -
Medicine and Science in Sports and... Sep 2008The International Olympic Committee Medical Commission (IOC-MC) requires athletes to provide the result of an objective test to support a diagnosis of asthma or...
PURPOSE
The International Olympic Committee Medical Commission (IOC-MC) requires athletes to provide the result of an objective test to support a diagnosis of asthma or exercise-induced bronchoconstriction (EIB) if they want to inhale a beta-2-agonist. The purpose of the study was to evaluate the airway response to a methacholine challenge and to hyperpnea induced by exercise in the field and in the laboratory or that induced voluntarily by eucapnic hyperpnea in a group of female elite swimmers.
METHODS
Sixteen female nonasthmatic elite swimmers performed a eucapnic voluntary hyperpnea (EVH) test, a field-based exercise test (FBT), a laboratory-based exercise test (LBT), and a methacholine challenge. The criteria suggested by the IOC-MC were used to define a positive response to the challenges (EVH, field test, and laboratory test: minimum 10% decrease in FEV1; methacholine: PD20 < or = 2 micromol).
RESULTS
Eight swimmers (50%) had at least one positive test to hyperpnea. Five were identified with the EVH test, four with FBT, and four with LBT. None were identified using methacholine. Three swimmers with airway hyperresponsiveness to exercise would have been identified using a higher cutoff for methacholine (PD20 < or = 8 micromol).
CONCLUSIONS
The EVH test is the test that diagnoses most swimmers with an abnormal response to hyperpnea, but not all cases of EIB are identified with the EVH test. Performing a methacholine test using IOC-MC's cutoff value does not improve the chances of diagnosing EIB. We recommend performing the EVH test when diagnosing and evaluating EIB in elite swimmers and if EVH test negative then proceeding to a strenuous LBT.
Topics: Adolescent; Airway Resistance; Asthma; Bronchi; Bronchoconstrictor Agents; Exercise; Female; Humans; Hyperventilation; Methacholine Chloride; Swimming; Young Adult
PubMed: 18685536
DOI: 10.1249/MSS.0b013e31875719a -
BioMed Research International 2017To investigate the repeatability and safety of measuring impulse oscillation system (IOS) parameters and the point of wheezing during bronchoprovocation testing of... (Clinical Trial)
Clinical Trial Observational Study
OBJECTIVE
To investigate the repeatability and safety of measuring impulse oscillation system (IOS) parameters and the point of wheezing during bronchoprovocation testing of preschool children.
METHODS
Two sets of methacholine challenge were conducted in 36 asthma children. The test was discontinued if there was a significant change in reactance (Xrs5) and resistance (Rrs5) at 5 Hz (Condition 1) or respiratory distress due to airway obstruction (Condition 2). The repeatability of PC_Xrs5, PC_Rrs5, and wheezing (PCw) was assessed. The changes in -scores and SD-indexes from prebaseline (before testing) to postbaseline (after bronchodilator) were determined.
RESULTS
For PC_Rrs5, PC_Xrs5, and PCw for subjects, PC_Xrs5 showed the highest repeatability. Fifteen of 70 tests met Condition 2. The changes from pre- and postbaseline values varied significantly for Rrs5 and Xrs5. Excluding subjects with -scores higher than 2SD, we were able to detect 97.1% of bronchial hyperresponsiveness during methacholine challenge based on the change in Rrs5 or Xrs5. A change in IOS parameters was associated with wheezing at all frequencies.
CONCLUSION
Xrs5 and Rrs5 have repeatability comparable with FEV1, and Xrs5 is more reliable than Rrs5. Clinicians can safely perform a challenge test by measuring the changes in Rrs5, Xrs5, and -scores from the prebaseline values.
Topics: Asthma; Bronchial Provocation Tests; Child, Preschool; Female; Humans; Male; Methacholine Chloride; Respiratory Mechanics
PubMed: 28740854
DOI: 10.1155/2017/9460190 -
The Journal of Allergy and Clinical... Sep 2004Deep inhalation has bronchodilating and bronchoprotective effects, particularly in subjects who are normal or have mild airway hyperresponsiveness (AHR). We have... (Clinical Trial)
Clinical Trial Comparative Study Randomized Controlled Trial
BACKGROUND
Deep inhalation has bronchodilating and bronchoprotective effects, particularly in subjects who are normal or have mild airway hyperresponsiveness (AHR). We have anecdotally observed that the 5 breath to total lung capacity (TLC) dosimeter method reduced the response to methacholine in some subjects with mild AHR.
OBJECTIVE
To compare prospectively submaximal inhalations with TLC inhalations during the dosimeter methacholine challenge.
METHODS
Sixteen subjects with asthma and a methacholine PC 20 <8 mg/mL performed 2 methacholine challenges in random order; the standard dosimeter method was compared with a modified dosimeter challenge in which methacholine inhalations were performed to approximately 50% to 60% below TLC.
RESULTS
The standard methacholine challenge PC 20 was almost twice that obtained with the modified submaximal inhalation method (geometric mean PC 20, 5.2 mg/mL vs 2.8 mg/mL, respectively; P = 0.0216). In the 5 subjects with the mildest AHR, there was a 2.5-fold to 14-fold difference in PC 20 between methods. The standard (full TLC) PC 20 s were falsely negative (>16 mg/mL) in these 5 subjects with current asthma, 4 of whom required inhaled corticosteroids.
CONCLUSION
A submaximal inhalation dosimeter methacholine challenge results in a significantly lower PC 20 compared with the standard 5-breath dosimeter method. This effect is limited to the mildly responsive group, probably because of the bronchoprotective effect of the deep inhalation during the standard method, and results in false-negative tests in some subjects.
Topics: Administration, Inhalation; Adult; Asthma; Bronchial Provocation Tests; Bronchoconstrictor Agents; False Negative Reactions; Female; Forced Expiratory Volume; Humans; Male; Methacholine Chloride; Middle Aged; Nebulizers and Vaporizers; Spirometry
PubMed: 15356550
DOI: 10.1016/j.jaci.2004.06.016 -
Allergy Dec 1995A number of investigations have indicated that cholinergic agonists release histamine from isolated mast cells and suggested that cholinergic stimulation releases... (Comparative Study)
Comparative Study
A number of investigations have indicated that cholinergic agonists release histamine from isolated mast cells and suggested that cholinergic stimulation releases histamine in vivo. The purpose of this study was to investigate whether the cutaneous wheal-and-flare reaction induced by methacholine challenge in human skin involves histamine release as measured by the skin microdialysis technique. Five hollow dialysis fibers were inserted intradermally in forearm skin in eight healthy subjects. Each fiber was perfused with Kreb's-Ringer bicarbonate at a rate of 3 microliters/min. Dialysates were collected in 2-min fractions before skin challenge and for 20 min after intradermal injection of methacholine 10(-3)-10(-1) M, the vehicle, and a positive control, codeine phosphate 0.3 mg/ml. Histamine was assayed spectrofluorometrically. Methacholine caused a statistically significant dose-related wheal-and-flare reaction, the flare reaction to methacholine 10(-1) M being comparable with that seen with codeine 0.3 mg/ml. No significant histamine release was observed with methacholine, cumulative histamine release of 16 +/- 8 nM by methacholine 10(-1) M being similar to vehicle responses of 15 +/- 9 nM. Histamine release by codeine was 2524 +/- 435 nM. In conclusion, methacholine-induced wheal-and-flare reactions in human skin appeared not to involve histamine release from skin mast cells.
Topics: Adult; Codeine; Female; Histamine Release; Humans; Injections, Intradermal; Male; Methacholine Chloride; Microdialysis; Middle Aged; Muscarinic Agonists; Narcotics; Skin; Skin Tests
PubMed: 8834827
DOI: 10.1111/j.1398-9995.1995.tb02510.x