DOCSLIB.ORG

Lung Hyperinflation and Flow Limitation in Chronic Airway Obstruction

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lung Hyperinflation and Flow Limitation in Chronic Airway Obstruction Eur Respir J 1997; 10: 543–549 Copyright ERS Journals Ltd 1997 DOI: 10.1183/09031936.97.10030511 European Respiratory Journal Printed in UK - all rights reserved ISSN 0903 - 1936 Lung hyperinflation and flow limitation in chronic airway obstruction R. Pellegrino*, V. Brusasco** Lung hyperinflation and flow limitation in chronic airway obstruction. R. Pellegrino, *Servizio di Fisiopatologia Respiratoria, V. Brusasco. ©ERS Journals Ltd 1997. Azienda Ospedaliera S. Croce e Carle, Cuneo, ABSTRACT: We reasoned that if flow limitation plays an important role in lung Italy. **Cattedra di Fisiopatologia Respira- hyperinflation, then bronchodilatation should be associated with a decrease of toria, Dipartimento di Scienze Motorie e Riabilitative, Università di Genova, Genova, functional residual capacity (FRC) only in subjects breathing under conditions of Italy. flow limitation. This hypothesis was tested in 33 subjects with chronic airway narrowing due to Correspondence: V. Brusasco asthma or chronic obstructive pulmonary disease (COPD). Flow limitation during Facoltà di Medicina e Chirurgia tidal breathing was inferred from the impingement of the tidal flow-volume loop Università di Genova on the flow recorded during submaximally forced expiratory manoeuvres initiat- Largo R. Benzi 10 ed from end-tidal inspiration. 16132 Genova At baseline, flow limitation during tidal breathing was present in seven asth- Italy matic (Group 1) and eight COPD subjects (Group 2), but absent in 11 asthmatic Keywords: Breathing pattern (Group 3) and seven COPD subjects (Group 4). FRC (mean±SEM) was similar in bronchodilatation the four groups (range 117±7 to 134±6% of predicted). Inhalation of salbutamol flow-volume curve (200 µg) caused significant increments of the forced expiratory volume in one functional residual capacity second (FEV1) (range 6±1 to 21±8% of baseline) and forced expiratory flows at 30% of baseline forced vital capacity (V'30) (range 58±13 to 235±93% of baseline) Received: May 23 1996 in all groups. In groups with flow limitation during tidal breathing at baseline the Accepted after revision December 2 1996 FRC measured by plethysmography decreased significantly (12±2% in Group 1, and 9±2% in Group 2), and the inspiratory capacity (IC) measured by spirome- try increased significantly (17±3% in Group 1 and 7±3% in Group 2). This was associated with flow limitation disappearing at the volume of baseline end-tidal expiration. In Groups 3 and 4 neither FRC nor IC changed significantly. The brea- thing pattern was not modified in any group after salbutamol. These findings suggest that flow limitation may contribute to generation of lung hyperinflation both in asthma and chronic obstructive pulmonary disease. We spe- culate that the increment of functional residual capacity could be triggered by dy- namic airway compression downstream from the flow-limiting segment. Eur Respir J 1997; 10: 543–549. Functional residual capacity (FRC) is generally increa- not increase until the decrement of forced expiratory sed in patients with airway narrowing due to chronic flow is such as to impinge on tidal expiratory flow [4]. obstructive pulmonary disease (COPD) or asthma [1]. On this basis, we hypothesized that in subjects with Part of this increment may be caused by the low elastic mild-to-moderate chronic bronchoconstriction who uti- recoil of the lung, which passively sets FRC at a vol- lize maximal expiratory flow during tidal expiration, i.e. ume higher than predicted. Nevertheless, bronchodila- breathing in flow limitation, bronchodilatation would tors may increase expiratory flow and decrease FRC in be associated with a decrease of FRC, whereas in pati- these individuals [1], suggesting that lung volume dur- ents who do not utilize maximal flow at any volume dur- ing tidal breathing is also dynamically regulated. ing tidal breathing, even if obstructed, bronchodilatation Recent observations have raised the suspicion that would not affect FRC. In addition, we investigated whe- there is an interesting relationship between FRC and ther the modulation of FRC by flow limitation is dif- expiratory flows. For example, unlike normal individ- ferent in COPD and bronchial asthma. uals, patients with mild-to-moderate COPD increase FRC during exercise as soon as the tidal expiratory flow en- croaches on the maximal flow-volume loop [2]. If a Methods threshold load, which reduces tidal flow, is suddenly applied during expiration under these circumstances, then FRC consistently and paradoxically decreases, in Subjects contrast to the situation when ventilation is not flow- limited [3]. Further evidence that FRC is coupled to The study included 33 subjects with chronic broncho- expiratory flow comes from the observation that when constriction due to bronchial asthma or COPD [5]. To bronchoconstriction is induced in asthmatics, FRC does enter the study, all individuals were required to have a 544 R. PELLEGRINO, V. BRUSASCO forced expiratory volume in one second (FEV1) >40% attained after the maximal expiratory manoeuvre and of predicted and a FEV1/forced vital capacity (FVC) the straight line joining the two TLCs (preceding and ratio below the normal range. The predicted values used following the full expiratory manoeuvre). FEV1 was were from QUANJER et al. [6]. None of the subjects was calculated by back-extrapolating the volume to TLC [6]. affected by other pulmonary or systemic disease. Before Flow from the partial expiratory manoeuvre was mea- the study, oral corticosteroids and theophylline were sured at 30% of control FVC (V'30). Changes in V'30 give avoided for 24 h, inhaled corticosteroids for 12 h, and a reliable estimate of the reversibility of airway obstruc- short-acting inhaled bronchodilators for 12 h. None of tion, as they are independent of the effects of deep inhala- the subjects was receiving long-acting bronchodilators. tion [9] and the time course of the preceding expiration. Informed consent was obtained before the study. Flow-volume curves without sharp peak flow were dis- carded and repeated. Lung function measurements Flow limitation. Flow limitation was detected by com- paring the flow-volume loops recorded during tidal brea- Flow was measured at the mouth by a screen-type thing and after a gentle forced expiration (with smooth pneumotachograph, linear up to 16 L·s-1, coupled to a peak flow) initiated from end-tidal inspiration without differential pressure transducer (Jaeger, Würzburg, Ger- breathholding. A deep inspiration to TLC recorded soon many). Volume was obtained by integration of the flow after the gentle forced manoeuvre allowed the loops to signal after careful correction for drift by manual ad- be superimposed and compared at absolute lung vol- justment of a potentiometer. ume. Particular care was taken that the inspiratory flow All lung function measurements were obtained, whilst before the gentle forced expiration was similar to that the subjects were in a sitting position, at least in tripli- of the previous tidal breaths. Flow limitation was defi- cate before and 20 min after salbutamol (200 µg, meter- ned as the condition of tidal expiratory flow impinging ed dose) was inhaled through a spacer. on the maximal flow generated during the gentle forced expiratory manoeuvre (fig. 1). Lung volumes. Thoracic gas volume (TGV) at end-tidal expiration (FRC) was measured in a constant-volume body Statistical analysis plethysmograph (Jaeger, Würzburg, Germany) by slow- ly panting against a closed shutter at the end of expi- Between- and within-groups analysis of variance ration [7]. Total lung capacity (TLC) was calculated by (ANOVA) with Newman Keuls post-hoc test was used adding to TGV the volume that could be maximally to assess the significance of differences between groups inhaled immediately after the opening of the shutter. and the changes after bronchodilatation. All data are Inspiratory capacity (IC) was measured on the spiro- presented as mean±SEM. A p-value less than 0.05 was gram as the difference between the straight line that best considered statistically significant. connected, by eye, the end-expiratory lung volumes of the last 6–7 regular breaths and TLC. Results Breathing pattern. After about 60 s of quiet and regu- lar breathing through the mouthpiece, 6–7 tidal regular Control condition breaths were plotted as a spirographic tracing on an XY recorder (LY 1400 Linseis, Selb, Germany), at a speed According to the presence or absence of flow limi- of 2 cm·s-1. Inspiratory (VTI) and expiratory (VTE) tidal tation and the clinical diagnosis, the subjects were div- volumes, respiratory frequency (fR), and inspiratory (tI) ided at the end of the study in four groups. Subjects and expiratory (tE) times were measured. Mean inspi- with flow limitation during tidal breathing at baseline ratory (VTI/t I) and expiratory (VTE/t E) flows, ratio of inspiratory time to total respiratory cycle time (tI/ttot), a) and minute ventilation (V'E) were then computed. b) Flow-volume curves. After regular breathing with no volume drift, the subjects performed a forced expira- tion from end-tidal inspiration without breathholding Flow (partial expiratory manoeuvre). Special care was taken Flow to coach the subjects not to slow down the inspiration preceding the partial forced manoeuvre, thus minimiz- ing the dependence of forced flows on the time of the preceding inspiration [8]. The subjects then took a fast Volume Volume deep breath to TLC and, without breathholding, force- Fig. 1. – Method used to detect flow limitation by comparing tidal fully expired to residual volume (RV) (full expiratory to forced expiratory flow-volume loops started from end-tidal inspi- manoeuvre), which was followed by another deep breath ration. a) Tidal breathing is flow-limited, as tidal expiratory flow to TLC to check for volume drift. The signals were first (interrupted line) impinges on submaximally forced expiratory flow displayed on a screen (Body Test Screen; Jaeger, Würzburg, (thick continuous line). Note that if expiratory effort is maximal (thin continuous line), then expiratory flow decreases due to thoracic gas Germany) and then slowly plotted on the XY recorder compression.
Load more

Recommended publications
  • New Spirometry Interpretation Algorithm Primary Care Respiratory Alliance of Canada Approach
    Critical Appraisal New spirometry interpretation algorithm Primary Care Respiratory Alliance of Canada approach Anthony D. D’Urzo MD MSc CCFP FCFP Itamar Tamari MD CCFP FCFP Jacques Bouchard MD Reuven Jhirad MD CCFP FCFP Pieter Jugovic MD MSc CCFP Clinical question Is there a need for a new spirometry interpretation algorithm that contains decision-making criteria consistent with current guidelines on asthma1 and chronic obstructive pulmonary disease (COPD)2 diagnosis? Using spirometry to distinguish between COPD and asthma Office spirometry provides valuable information about the relationship between flow and volume in relation to lung function and can be useful for diagnosing common conditions such as asthma and COPD.1,2 Mechanical abnor- malities of the respiratory system can be classified as either obstructive (flow-related) or restrictive (volume-related) ventilatory defects; obstructive defects are much more common in clinical practice. The relationship between flow and volume is described well by BOTTOM LINE • An algorithm commonly promoted in the ratio of the forced expiratory volume in 1 second (FEV1) to the forced vital capacity (FVC). These measurements can be easily obtained with a primary care is limited by its focus on using simple office spirometer during a forced expiratory maneuver. The ratio changes in forced expiratory volume in 1 second (FEV ) to distinguish asthma from of FEV1 to FVC can be useful to identify obstructive, restrictive, and com- 1 bined (obstructive-restrictive) defects, but it is important to recognize that chronic obstructive pulmonary disease total lung capacity, a more sophisticated measurement (and not the FVC), (COPD). The new algorithm consolidates is the best measurement to confirm a diagnosis of pulmonary restriction.3 current spirometric concepts that are consistent with both asthma and COPD Traditionally an FEV1-FVC ratio below 0.70 has been used to define a pure obstructive defect if the FVC is within normal limits.
    [Show full text]
  • Pulse Oximetry Is Essential in Home Management of Elderly COVID-19 Patients Md
    55 Bangladesh J Otorhinolaryngol 2020; 26(1): 55-67 Case Report Pulse Oximetry is Essential in Home Management of Elderly COVID-19 Patients Md. Abdullah Al Harun1, Mohammad Murad Hossain2, Mohammad Anwarul Bari3, Nazmul Ahsan Siddiqi Rubel4, Mohammad Enamul Karim5, Nadia Siddiquee6, Mohammad Delwar Hossain7, Farhana Sultana8, Ahmmad Taous9, AKM Monwarul Islam10, Salma Khatun11, AHM Afzalul Haque12, Mohammad Mahbub-Ul Haque13, KM Mamun Murshed14, Syed Atiqullah15, Abu Mohammad Ekramul Hoque16, Mohammad Abdullah17 Abstract Background: Coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) is in Pandemic form and has affected people of 215 countries. It produces symptoms like fever, cough, shortness of breath, sore throat, headache, loss of taste, smell or appetite and many other rare symptoms. But the most important symptom is shortness of breath due to hypoxia. In a normal individual oxygen saturation (SpO2) is at least 95% and patient feels shortness of breath when SpO2 falls below 90% with some exception. SARS-CoV-2, a newly emergent coronavirus has the peculiarity to produce silent hypoxia, meaning SpO2< 90% or less like 80%, 70%, 60% without shortness of breath. Silent hypoxia can be diagnosed by monitoring SpO2 with pulse oximeter. For management of COVID-19, early symptoms like fever & cough, SpO2 should be monitored by pulse oximeter, followed by immediate correction of hypoxia by O2 supplementation and prophylactic oral or injectable anticoagulant to prevent thromboembolism and thus death rate can be reduced. Case summary: A 72-year-old man presented with the complaints of fever and headache followed by cough, fatigue, anorexia, loss of taste and appetite in next few days but no shortness of breath.
    [Show full text]
  • Effect of Inspiratory Flow Rate on Bronchomotor Tone in Normal and Asthmatic Subjects
    Thorax: first published as 10.1136/thx.39.2.86 on 1 February 1984. Downloaded from Thorax 1984;39:86-92 Effect of inspiratory flow rate on bronchomotor tone in normal and asthmatic subjects W HIDA, M ARAI, C SHINDOH, Y-N LIU, H SASAKI, T TAKISHIMA From the First Department ofInternal Medicine, Tohoku University School of Medicine, Sendai, Japan ABSTRACT The effect of the inspiratory flow rate during deep inspiration on the regulation of bronchomotor tone was studied in nine normal and 22 asthmatic subjects. Changes in bronchial tone were assessed by respiratory resistance measured by an oscillation method. In normal subjects with bronchoconstriction induced by methacholine a rapid deep inspiration reduced respiratory resistance more than a slow deep inspiration. Asthmatic subjects with spontaneous airway narrowing showed an increase in respiratory resistance after deep inspiration that was greater after rapid than after slow deep inspiration. On the other hand, in asthmatics with methacholine induced bronchoconstriction, bronchodilatation occurred after deep inspiration and this was also greater after rapid than after slow deep inspiration. Lignocaine inhalation attenuated both bronchoconstriction and bronchodilatation induced by both slow and rapid deep inspiration. These results suggest that the effects of deep inspiration are mediated at least in part via receptors in the airways. It is suggested that in asthmatic patients with spontaneous broncho- constriction irritant receptor activity will be increased in proportion to the speed of inspiration. After methacholine induced bronchoconstriction stretch receptor activity is likely to behave in a similar fashion, leading to an opposite effect. http://thorax.bmj.com/ A deep inspiration has been reported to produce a carbachol induced bronchoconstriction, and they transient decrease in airway calibre in some asthma- suggested that this might have been due to greater tic subjects.' 2 In contrast, in the presence of phar- stimulation of stretch receptors at higher flows.
    [Show full text]
  • Global Strategy for Asthma Management and Prevention, 2019. Available From
    DISTRIBUTE OR COPY NOT DO MATERIAL- COPYRIGHTED ASTHMA MANAGEMENT AND PREVENTION GLOBAL STRATEGY FOR Updated 2019 9 Global Strategy for Asthma Management and Prevention (2019 update) DISTRIBUTE OR COPY NOT DO The reader acknowledges that this reportMATERIAL- is intended as an evidence-based asthma management strategy, for the use of health professionals and policy-makers. It is based, to the best of our knowledge, on current best evidence and medical knowledge and practice at the date of publication. When assessing and treating patients, health professionals are strongly advised to use their own professional judgment, and to take into account local or national regulations and guidelines. GINA cannot be held liable or responsible for inappropriate healthcare associated with the use of this document, including any use which is not in accordance with applicable local or national regulations or COPYRIGHTEDguidelines. This document should be cited as: Global Initiative for Asthma. Global Strategy for Asthma Management and Prevention, 2019. Available from: www.ginasthma.org 1 Table of contents Tables and figures ............................................................................................................................................................... 5 Preface ................................................................................................................................................................................. 7 Members of GINA committees (2018) ................................................................................................................................
    [Show full text]
  • Hypoxaemia in Wheezy Infants After Bronchodilator Treatment
    Arch Dis Child: first published as 10.1136/adc.62.10.997 on 1 October 1987. Downloaded from Archives of Disease in Childhood, 1987, 62, 997-1000 Hypoxaemia in wheezy infants after bronchodilator treatment A PRENDIVILLE, A ROSE, D L MAXWELL, AND M SILVERMAN Department of Paediatrics and Neonatal Medicine, and Division of Respiratory Medicine, Royal Postgraduate Medical School, London SUMMARY The response of the bronchi to nebulised salbutamol was measured in five recurrently wheezy infants. Changes in oxygenation (measured by pulse oximeter and transcutaneous P02 electrodes) and carbon dioxide (measured by transcutaneous PCO2 electrode) were recorded at the same time. Neither nebulised saline nor salbutamol caused any changes in the measurements of airway function. A significant drop in mean oxygen saturation of 2% and of transcutaneous oxygen tension of 1*3 kPa occurred after nebulised salbutamol. No significant change occurred in measurements of transcutaneous carbon dioxide tension, nor was there any significant change in any of these measurements after 2-5 ml of nebulised saline had been given as a control. These results suggest that nebulised salbutamol may cause significant hypoxaemia, in wheezy infants probably by inducing ventilation/perfusion disturbance. copyright. Nebulised selective P2-adrenoceptor agonists are All were wheezy at the time of testing. The still used in the treatment of wheezing in infants in reproducibility of the response to salbutamol was spite of the evidence that they may be ineffective. 1-3 assessed two weeks later in four of the infants. The Recently they have been shown to cause deteriora- fifth infant did not have a repeat study because he tion in peripheral airways function in this age developed severe bronchoconstriction after the group.4 Because the techniques used for measur- initial treatment with salbutamol.
    [Show full text]
  • Human Respiratory Tract
    Thorax: first published as 10.1136/thx.36.1.52 on 1 January 1981. Downloaded from Thorax, 1981, 36, 52-55 Deposition of pressurised aerosols in the human respiratory tract STEPHEN P NEWMAN, DEMETRI PAVIA, FOLKE MOREN, NOIRIN F SHEAHAN, AND STEWART W CLARKE From the Departments of Medical Physics and Thoracic Medicine, The Royal Free Hospital, London, and A B Draco, Lund, Sweden ABSTRACT Although the use of pressurised aerosol inhalers is widespread, little is known about the actual deposition of the aerosol in the respiratory tract, since this has previously been diffi- cult to measure. We have incorporated Teflon particles (mean diameter 2 Itm) with aerodynamic properties similar to those of bronchodilator drug crystals into pressurised aerosol canisters. Controlled inhalations by eight patients with obstructive airways disease showed that on average 8-8% of the dose was deposited in the lungs (3 0% in the alveoli and 5'8% on the conducting airways) and 80% in the mouth. These figures are in good agreement with previous indirect estimates of deposition based on metabolic studies. The remainder of the dose was either expired (1 0%) or deposited in the aerosol actuator (9P8%). This method should have wide application for measurement of deposition patterns under various conditions and for assessment of thera- peutic effects. Since the identification of specific 62 receptors in centages of the dose deposited on the conducting http://thorax.bmj.com/ the human respiratory tract,' selective sympatho- airways and in the alveoli are unknown. In this mimetic bronchodilator aerosols have been in paper we present the first direct measurement of common use for the treatment of asthma.
    [Show full text]
  • COPD Diagnosis Related to Different Guidelines and Spirometry Techniques Lennart Nathell1,2, Madelene Nathell1, Per Malmberg3 and Kjell Larsson*4
    Respiratory Research BioMed Central Review Open Access COPD diagnosis related to different guidelines and spirometry techniques Lennart Nathell1,2, Madelene Nathell1, Per Malmberg3 and Kjell Larsson*4 Address: 1Personal Injury Prevention Section, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden , 2Medical advisor, Deparment of Medical Affairs, Boehringer Ingelheim, Stockholm, 3National Institute for Working Life, Stockholm, Sweden and 4National Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden Email: Lennart Nathell - [email protected]; Madelene Nathell - [email protected]; Per Malmberg - [email protected]; Kjell Larsson* - [email protected] * Corresponding author Published: 4 December 2007 Received: 26 March 2007 Accepted: 4 December 2007 Respiratory Research 2007, 8:89 doi:10.1186/1465-9921-8-89 This article is available from: http://respiratory-research.com/content/8/1/89 © 2007 Nathell et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract The aim was to compare the diagnosis of COPD among smokers according to different international guidelines and to compare the outcome when using slow (SVC) and forced vital capacity (FVC). In order to find current smokers a questionnaire was sent to persons who had been on sick leave for more than two weeks. Those who smoked more than 8 cigarettes per day were invited to perform a spirometry. Totally 3,887 spirometries were performed. In this sample 10.2% fulfilled the NICE COPD-criteria, 14.0% the GOLD COPD-criteria and 21.7% the ERS COPD criteria.
    [Show full text]
  • Drugs Used in Asthma and COPD
    Drugs used in Asthma and COPD Objective : 1. Different types of drugs used for treatment of asthma 2. Differentiate between treatment and prophylactic therapy for asthma 3. Recognize the different types of bronchodilators regarding pharmacokinetics, pharmacodynamics, uses and side effects. 4. Identify the different anti-inflammatory drugs for asthma in respect to kinetics, dynamics, uses and side effects. § Addi-onal Notes § Important § Explanaon –Extra- For any correc-on, sugges-on or any useful informaon do not hesitate to contact us: [email protected] Bronchial Asthma It is a chronic inflammatory disorder of bronchial airways that result in airway obstruction in response to external stimuli (as pollen grains, cold air and tobacco smoke). • Asthma produces recurrent episodic attack of : Acute bronchoconstriction, Shortness of breath, Chest tightness, Wheezing, Rapid respiration, Cough. Symptoms • Symptoms can happen each time the airways are irritated by inhaled irritants or allergens. • Infection, Stress, Exercise (cold air), Pets, Seasonal changes, Emotional conditions, Some drugs as aspirin, β- blockers. Causes • Airway hyper-reactivity: abnormal sensitivity of the airways to any external stimuli. • Inflammation:↑ edema, swelling +↑ Thick mucus production. Characters • Bronchospasm (constriction of the bronchial smooth muscles). of airways Irritant receptors in upper airways. We want to enhance the Afferent nerves sympathetic or (sensory) inhibit the C-fiber receptors in lower airways. parasympathetic in this case. Airways Innervations Parasympathetic supply M3 receptors in smooth muscles and glands: Bronchoconstriction and Increase mucus secretion. Efferent nerves (motor nerves) No sympathetic supply but β2 receptors in smooth Afferent nerves (sensory) are stimulated by: muscles and glands: Bronchodilatation, Decrease mucus - Exogenous chemicals or irritants secretion.
    [Show full text]
  • Comparative Effects of Volume History on Bronchoconstriction Induced by Hyperventilation and Methacholine in Asthmatic Subjects
    Eur Respir J 1990, 3, 63~43 Comparative effects of volume history on bronchoconstriction induced by hyperventilation and methacholine in asthmatic subjects J-L. Malo, J. L'Archev~que, A. Cartier Comparative effects of volume history on bronchoconstriction induced by Dept of Chest Medicine, H8pital du Sacr~-Coeur, hyperventilation and methacholine in asthmatic subjects. J-L. Malo, J. Montreal, Canada. L'Archeveque, A. Cartier. ABSTRACT: The aim of tWs study was to find out lf bronchodilatatlon following deep Inspiration can be Induced by the Inhalation of a "natural" Correspondence: J-L. Malo, Dept of Chest Medicine, stimulus (hyperventilation or cold dry air), and If the effect Is slmUar to Hopital du Sacre-Coeur, 5400 W. Gouin, Montreal, that Induced by methacholine. After basellne assessment of lung resistance Canada H4J 1C5. (RL), 10 asthmatic subjects were asked to Inhale cold dry air for 3 min. RL was monitored contlnuotL~Iy for 3-4 mln, at which time subjects were asked to take a fa.st deep inspiration. After recovery, the manoeuvre was repeated and RL was reassessed. The manoeuvre was then repeated a Keywords: Asthma; bronchi; bronchial provocation third time. After functional r ecovery, progressive doses of methacholine tests; obstructive lung diseases. were Inhaled until the Increase In RL was comparable to that obtained after hyperventilation (56±16% and 65±24%, r espectively, mean±so, NS). The same deep Inspiration manoeuvre was repeated three times with Received: May 29, 1989; accepted after revision recovery as after hyperventiJatlon of cold dry alr. Maximum changes In February 13, 1990. RL were not slgntncantly different after each or the three manoeuvr es for either type or bronchoconstrlction.
    [Show full text]
  • Rsibility of Induced Bronchoconstriction by Deep Inspiration in Asthmatic and Normal Subjects
    rsibility of induced bronchoconstriction by deep inspiration in asthmatic and normal subjects J.R. Wheatley, P.D. Pare, LA. Enget of induced bronchoconstriction by deep inspiration in asthmatic Thoracic Medicine Unit, Westmead Hospital, ., ...,~"~''" · J.R. Wheatley, P.D. Pare, L.A. Engel. Wes!mead NSW 2145, Australia . normal and flve asthmatic subjects underwent a Correspoodence: Dr I.R. Wheatley, Tho111cic Medi· methacholine provocation study. Af each concentration In· cine Unit. Dept of Medicine. We..trnead Hospital. pulmonary resistance (RL) was measured, as well as lsovolumlc We..tmead NSW 2145, Australia. now and residual volume from both partial and complete Keywords: Airway closure; airway obstruction; lrallons. Results were compared over the RL range of '-11 aitway mislllnce; panial flow-volume curve•. 1• The reversibility of bronchoconstrlctlon by deep Inspiration as the ratio or the flow Increase to potential maximal In· Received: February, 1988; accepted after revision: the reverslblUty or gas trapping was the ratio or decrease In November 21, 1988. volume to potential maximal decrease. The reverslblllty or bron- Supported by NSW Department of Health and NH lon did not differ between the groups. In contrast, the revers!· and-MRC of Australia. tra,~nlru• was smaller In asthmatic subjects (21±17%) than ). As gas trapping renects airway closure, our find­ that during Induced bronchoconstrlctlon airway closure ls ~11sta 1nt to the effects or deep Inspiration In asthmutk: than In subjects but the reversibility or bronchoconstrlctlon by deep ls not different. J .. 1989, 2, 331-339. c0onnal subjects with pharmacologically-induced reference lung volume and decreases in residual volume, a deep inspiration transiently re­ following a deep inspiration, we derived indices of airway resistance [1).
    [Show full text]
  • Defining and Describing Airways Obstruction in Children
    WIESBADEN SYMPOSIUM 1083 Defining and describing airways obstruction in children K.F. Kerrebijn* The two most common diseases with airway obstruc­ expression of the results. This can be done in absolute tion from pre-school age are asthma and cystic fibrosis values (not applicable in children be(:ause of differences (CF). Airway diseases in infancy will not be discussed. in size), % of baseline, o/o of predicted and % achiev­ For reasons of simplicity, asthma is defined as the able (predicted minus baseline). Results which are ex­ complex coexistance of one or more of the symptoms pressed in % of baseline and % achievable are dependent wheeze, breathlessness, cough, mucus hypersecretion, on the initial value in contrast to results expressed in % which are either chronically or intermittently present of predicted (table 1). and which are generally triggered by viral infections, Table 1. - Predicted 2500 ml; increase after allergens, pollutants (cigarette smoke), exercise, sudden bronchodilatation 250 ml. changes in temperature of the inspired air etc. Increase after bronchodilatation % baseline % predicted % achievable Criteria for airway obstruction 1000-1250 25 10 16.6 1500-1750 16.6 10 25 Diminishment of airway calibre 2000-2250 12.5 10 50 In most patients with asthma and CF, airway calibre is diminished. This may however be within the normal range. Criteria for diminishment are an absolute value Reference values for bronchodilator responses in of the index taken which is 1) lower than -2 standard healthy children and adolescents, expressed in % of deviations from predicted or 2) lower than -1.65 stand­ baseline are given by CASAN et al [4] and in ard scores (SS) (measured minus predicted value/within asymptomatic, never smoking subjects aged 7-75 years subject coefficient of variation), which indicates the in % of predicted by DALES et al [5}.
    [Show full text]
  • Childhood Asthma Outcomes During the COVID-19 Pandemic: Findings from the Pearl Multi-National Cohort
    medRxiv preprint doi: https://doi.org/10.1101/2020.10.27.20219436; this version posted October 28, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. Childhood asthma outcomes during the COVID-19 pandemic: Findings from the PeARL multi-national cohort. Authors: Nikolaos G. Papadopoulos MD, PhD, FRCP, FAAAAI1,2, Alexander G. Mathioudakis MD, MRCP(UK)1,3,Adnan Custovic MSc, DM, MD, PhD, FRCP4, Antoine Deschildre MD5, Wanda Phipatanakul MD, MS6, Gary Wong MD, FRCPC, FHKAM7, Paraskevi Xepapadaki MD, PhD2, Rola Abou-Taam MD8, Ioana Agache MD9, Jose A. Castro-Rodriguez MD10, Zhimin Chen MD, PhD11, Pierrick Cros MD12, Jean-Christophe Dubus MD13, Zeinab Awad El-Sayed MD, PhD14, Rasha El- Owaidy MD, PhD14, Wojciech Feleszko MD15, Vincenzo Fierro MD16, Alessandro Fiocchi MD16, Luis Garcia-Marcos MD, PhD17,18, Anne Goh MD19, Elham M. Hossny MD, PhD, FAAAAI14, Yunuen R. Huerta Villalobos MD20, Tuomas Jartti MD21, Pascal Le Roux MD22, Julia Levina MD23, Aida Inés López García MD24, Ángel Mazón Ramos MD25, Mário Morais-Almeida MD, MSc, PhD 26, Clare Murray MBChB, MD, MRCP, MRCPHCH1, Karthik Nagaraju MD27, Major K Nagaraju MD28, Elsy Maureen Navarrete Rodriguez MD29, Leyla Namazova-Baranova MD, PhD23,30, Antonio Nieto Garcia MD, PhD25, Cesar Fireth Pozo Beltrán MD31,32, Thanaporn Ratchataswan MD6, Daniela Rivero Yeverino MD33, Eréndira Rodríguez Zagal MD20, Cyril E Schweitzer MD34, Marleena Tulkki MD35, Katarzyna Wasilczuk MD15, Dan XU MD, PhD11 , PeARL collaborators*, on behalf of the PeARL Think Tank**.
    [Show full text]