Peak Expiratory Flow Rate: Measurement of the maximum rate of airflow attained during a FORCED VITAL CAPACITY determination. Common abbreviations are PEFR and PFR.Forced Expiratory Flow Rates: The rate of airflow measured during a FORCED VITAL CAPACITY determination.Asthma: A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).Maximal Expiratory Flow Rate: The airflow rate measured during the first liter expired after the first 200 ml have been exhausted during a FORCED VITAL CAPACITY determination. Common abbreviations are MEFR, FEF 200-1200, and FEF 0.2-1.2.Forced Expiratory Volume: Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.Albuterol: A short-acting beta-2 adrenergic agonist that is primarily used as a bronchodilator agent to treat ASTHMA. Albuterol is prepared as a racemic mixture of R(-) and S(+) stereoisomers. The stereospecific preparation of R(-) isomer of albuterol is referred to as levalbuterol.Vital Capacity: The volume of air that is exhaled by a maximal expiration following a maximal inspiration.Respiratory Function Tests: Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.Bronchodilator Agents: Agents that cause an increase in the expansion of a bronchus or bronchial tubes.Spirometry: Measurement of volume of air inhaled or exhaled by the lung.Administration, Inhalation: The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.Beclomethasone: An anti-inflammatory, synthetic glucocorticoid. It is used topically as an anti-inflammatory agent and in aerosol form for the treatment of ASTHMA.Ipratropium: A muscarinic antagonist structurally related to ATROPINE but often considered safer and more effective for inhalation use. It is used for various bronchial disorders, in rhinitis, and as an antiarrhythmic.Atropine Derivatives: Analogs and derivatives of atropine.Nebulizers and Vaporizers: Devices that cause a liquid or solid to be converted into an aerosol (spray) or a vapor. It is used in drug administration by inhalation, humidification of ambient air, and in certain analytical instruments.Airway Obstruction: Any hindrance to the passage of air into and out of the lungs.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Anti-Asthmatic Agents: Drugs that are used to treat asthma.Pulmonary Ventilation: The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.Asthma, Exercise-Induced: Asthma attacks following a period of exercise. Usually the induced attack is short-lived and regresses spontaneously. The magnitude of postexertional airway obstruction is strongly influenced by the environment in which exercise is performed (i.e. inhalation of cold air during physical exertion markedly augments the severity of the airway obstruction; conversely, warm humid air blunts or abolishes it).Terbutaline: A selective beta-2 adrenergic agonist used as a bronchodilator and tocolytic.Aerosols: Colloids with a gaseous dispersing phase and either liquid (fog) or solid (smoke) dispersed phase; used in fumigation or in inhalation therapy; may contain propellant agents.Maximal Expiratory Flow-Volume Curves: Curves depicting MAXIMAL EXPIRATORY FLOW RATE, in liters/second, versus lung inflation, in liters or percentage of lung capacity, during a FORCED VITAL CAPACITY determination. Common abbreviation is MEFV.Lung Diseases, Obstructive: Any disorder marked by obstruction of conducting airways of the lung. AIRWAY OBSTRUCTION may be acute, chronic, intermittent, or persistent.Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Bronchitis: Inflammation of the large airways in the lung including any part of the BRONCHI, from the PRIMARY BRONCHI to the TERTIARY BRONCHI.Budesonide: A glucocorticoid used in the management of ASTHMA, the treatment of various skin disorders, and allergic RHINITIS.Bronchial Provocation Tests: Tests involving inhalation of allergens (nebulized or in dust form), nebulized pharmacologically active solutions (e.g., histamine, methacholine), or control solutions, followed by assessment of respiratory function. These tests are used in the diagnosis of asthma.Dust: Earth or other matter in fine, dry particles. (Random House Unabridged Dictionary, 2d ed)Respiration Disorders: Diseases of the respiratory system in general or unspecified or for a specific respiratory disease not available.Respiratory Tract DiseasesPregnenediones: Unsaturated pregnane derivatives containing two keto groups on side chains or ring structures.Leukotriene Antagonists: A class of drugs designed to prevent leukotriene synthesis or activity by blocking binding at the receptor level.Cough: A sudden, audible expulsion of air from the lungs through a partially closed glottis, preceded by inhalation. It is a protective response that serves to clear the trachea, bronchi, and/or lungs of irritants and secretions, or to prevent aspiration of foreign materials into the lungs.Air Pollutants: Any substance in the air which could, if present in high enough concentration, harm humans, animals, vegetation or material. Substances include GASES; PARTICULATE MATTER; and volatile ORGANIC CHEMICALS.Fenoterol: An adrenergic beta-2 agonist that is used as a bronchodilator and tocolytic.Airway Resistance: Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.Respiratory Sounds: Noises, normal and abnormal, heard on auscultation over any part of the RESPIRATORY TRACT.Lung Volume Measurements: Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.Occupational Diseases: Diseases caused by factors involved in one's employment.Total Lung Capacity: The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.Circadian Rhythm: The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.Maximal Midexpiratory Flow Rate: Measurement of rate of airflow over the middle half of a FORCED VITAL CAPACITY determination (from the 25 percent level to the 75 percent level). Common abbreviations are MMFR and FEF 25%-75%.Adrenergic beta-Agonists: Drugs that selectively bind to and activate beta-adrenergic receptors.Clinical Trials as Topic: Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.Adrenal Cortex HormonesTime Factors: Elements of limited time intervals, contributing to particular results or situations.Acute Disease: Disease having a short and relatively severe course.Cross-Over Studies: Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)Respiratory Mechanics: The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.Occupational Exposure: The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.Prednisolone: A glucocorticoid with the general properties of the corticosteroids. It is the drug of choice for all conditions in which routine systemic corticosteroid therapy is indicated, except adrenal deficiency states.Respiration: The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).Physical Exertion: Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.Glucocorticoids: A group of CORTICOSTEROIDS that affect carbohydrate metabolism (GLUCONEOGENESIS, liver glycogen deposition, elevation of BLOOD SUGAR), inhibit ADRENOCORTICOTROPIC HORMONE secretion, and possess pronounced anti-inflammatory activity. They also play a role in fat and protein metabolism, maintenance of arterial blood pressure, alteration of the connective tissue response to injury, reduction in the number of circulating lymphocytes, and functioning of the central nervous system.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Random Allocation: A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.Chronic Disease: Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)Methacholine Chloride: A quaternary ammonium parasympathomimetic agent with the muscarinic actions of ACETYLCHOLINE. It is hydrolyzed by ACETYLCHOLINESTERASE at a considerably slower rate than ACETYLCHOLINE and is more resistant to hydrolysis by nonspecific CHOLINESTERASES so that its actions are more prolonged. It is used as a parasympathomimetic bronchoconstrictor agent and as a diagnostic aid for bronchial asthma. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1116)Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Ozone: The unstable triatomic form of oxygen, O3. It is a powerful oxidant that is produced for various chemical and industrial uses. Its production is also catalyzed in the ATMOSPHERE by ULTRAVIOLET RAY irradiation of oxygen or other ozone precursors such as VOLATILE ORGANIC COMPOUNDS and NITROGEN OXIDES. About 90% of the ozone in the atmosphere exists in the stratosphere (STRATOSPHERIC OZONE).Bronchi: The larger air passages of the lungs arising from the terminal bifurcation of the TRACHEA. They include the largest two primary bronchi which branch out into secondary bronchi, and tertiary bronchi which extend into BRONCHIOLES and PULMONARY ALVEOLI.Dyspnea: Difficult or labored breathing.Drug Therapy, Combination: Therapy with two or more separate preparations given for a combined effect.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Drug Administration Schedule: Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience.Expiratory Reserve Volume: The extra volume of air that can be expired with maximum effort beyond the level reached at the end of a normal, quiet expiration. Common abbreviation is ERV.Smoking: Inhaling and exhaling the smoke of burning TOBACCO.Lung Diseases: Pathological processes involving any part of the LUNG.IndiaBronchial Hyperreactivity: Tendency of the smooth muscle of the tracheobronchial tree to contract more intensely in response to a given stimulus than it does in the response seen in normal individuals. This condition is present in virtually all symptomatic patients with asthma. The most prominent manifestation of this smooth muscle contraction is a decrease in airway caliber that can be readily measured in the pulmonary function laboratory.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Ethanolamines: AMINO ALCOHOLS containing the ETHANOLAMINE; (-NH2CH2CHOH) group and its derivatives.Tidal Volume: The volume of air inspired or expired during each normal, quiet respiratory cycle. Common abbreviations are TV or V with subscript T.Inspiratory Capacity: The maximum volume of air that can be inspired after reaching the end of a normal, quiet expiration. It is the sum of the TIDAL VOLUME and the INSPIRATORY RESERVE VOLUME. Common abbreviation is IC.Aerosol Propellants: Compressed gases or vapors in a container which, upon release of pressure and expansion through a valve, carry another substance from the container. They are used for cosmetics, household cleaners, and so on. Examples are BUTANES; CARBON DIOXIDE; FLUOROCARBONS; NITROGEN; and PROPANE. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Functional Residual Capacity: The volume of air remaining in the LUNGS at the end of a normal, quiet expiration. It is the sum of the RESIDUAL VOLUME and the EXPIRATORY RESERVE VOLUME. Common abbreviation is FRC.Androstadienes: Derivatives of the steroid androstane having two double bonds at any site in any of the rings.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.
Swiss Institute of Allergy and Asthma Research: Swiss Institute of Allergy and Asthma Research (SIAF), founded in 1988, performs basic research in the field of allergy and asthma with the aim to improve the understanding and treatment of these conditions, which affect around 30-40% of the westernized population. The Institute has its roots in the Tuberculosis Research Institute of Davos, a medical society founded in 1905 to study the beneficial effects of high altitude treatment of tuberculosis.Ventolin (EP): "Ventolin" is a piece of electronic music composed by Cornish musician Richard D James. It is noted for its harsh, abrasive sound.Bronchodilator: A bronchodilator is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lungs. Bronchodilators may be endogenous (originating naturally within the body), or they may be medications administered for the treatment of breathing difficulties.Spirometer: A spirometer is an apparatus for measuring the volume of air inspired and expired by the lungs. A spirometer measures ventilation, the movement of air into and out of the lungs.Estradiol dipropionateIpratropium bromideMethylatropineAnaesthetic vaporizerLung receptor: Lung receptors sense irritation or inflammation in the bronchi and alveoli.BambuterolAerosolization: Aerosolization is the process or act of converting some physical substance into the form of particles small and light enough to be carried on the air i.e.EprozinolPlacebo-controlled study: Placebo-controlled studies are a way of testing a medical therapy in which, in addition to a group of subjects that receives the treatment to be evaluated, a separate control group receives a sham "placebo" treatment which is specifically designed to have no real effect. Placebos are most commonly used in blinded trials, where subjects do not know whether they are receiving real or placebo treatment.Eosinophilic bronchitis: Eosinophilic bronchitis is a type of airway inflammation due to excessive mast cell recruitment and activation in the superficial airways as opposed to the smooth muscles of the airways as seen in asthma. It often results in a chronic cough.BudesonideMineral dust: Mineral dust is a term used to indicate atmospheric aerosols originated from the suspension of minerals constituting the soil, being composed of various oxides and carbonates. Human activities lead to 30% of the dust load in the atmosphere.DeflazacortZafirlukastHabit cough: A habit cough (also known as psychogenic cough and pseudoasthma) is a cough that may develop in children or adolescents after a cold or other airway irritant. It has also been reported in adults.P-AnisidineFenoterolMidnight: Midnight is the transition time period from one day to the next: the moment when the date changes. In ancient Roman timekeeping, midnight was halfway between sunset and sunrise, varying according to the seasons.Long-acting beta-adrenoceptor agonist: Long-acting beta-adrenoceptor agonists (LABAs, more specifically β2-agonists) are usually prescribed for moderate to severe persistent asthma patients or patients with chronic obstructive pulmonary disease (COPD). They are designed to reduce the need for shorter-acting β2-agonists such as salbutamol, as they have a duration of action of approximately 12 hours in comparison with the 4- to 6-hour duration of salbutamol, making them candidates for sparing high doses of corticosteroids or treating nocturnal asthma and providing symptomatic improvement in patients with COPD.Community-based clinical trial: Community-based clinical trials are clinical trials conducted directly through doctors and clinics rather than academic research facilities. They are designed to be administered through primary care physicians, community health centers and local outpatient facilities.Temporal analysis of products: Temporal Analysis of Products (TAP), (TAP-2), (TAP-3) is an experimental technique for studyingCheyne–Stokes respirationOccupational hygiene: Occupational (or "industrial" in the U.S.PrednisoloneDimefoxNon-communicable disease: Non-communicable disease (NCD) is a medical condition or disease that is non-infectious or non-transmissible. NCDs can refer to chronic diseases which last for long periods of time and progress slowly.MethacholineOzone Action Day: An Ozone Action Day, which can be declared by a local municipality, county or state, is observed at certain times during the summer months, when weather conditions (such as heat, humidity, and air stagnation) run the risk of causing health problems.Bronchus: A bronchus, also known as a main or primary bronchus, is a passage of airway in the respiratory tract that conducts air into the lungs. There is a right bronchus and a left bronchus and these bronchi branch into smaller secondary and tertiary bronchi which branch into smaller tubes, known as bronchioles.Combination therapy: Combination therapy or polytherapy is therapy that uses more than one medication or modality (versus monotherapy, which is any therapy taken alone). Typically, these terms refer to using multiple therapies to treat a single disease, and often all the therapies are pharmaceutical (although it can also involve non-medical therapy, such as the combination of medications and talk therapy to treat depression).Superficial velocity: Superficial velocity (or superficial flow velocity), in engineering of multiphase flows and flows in porous media, is a hypothetical (artificial) flow velocity calculated as if the given phase or fluid were the only one flowing or present in a given cross sectional area. Other phases, particles, the skeleton of the porous medium, etc.Ethernet flow control: Ethernet flow control is a mechanism for temporarily stopping the transmission of data on Ethernet family computer networks. The first flow control mechanism, the PAUSE frame, was defined by the IEEE 802.Chronic lung diseaseTamil Nadu Dr. M.G.R. Medical UniversityBronchial hyperresponsiveness: Bronchial hyperresponsiveness (or other combinations with airway or hyperreactivity) is a state characterised by easily triggered bronchospasm (contraction of the bronchioles or small airways).Closed-ended question: A closed-ended question is a question format that limits respondents with a list of answer choices from which they must choose to answer the question.Dillman D.PhosphorylethanolaminePlateau pressure: Plateau pressure (PPLAT) is the pressure applied to small airways and alveoli during positive-pressure mechanical ventilation.Morgan, Edward G.Rocket propellant: Rocket propellant is a material used by a rocket as, or to produce in a chemical reaction, the reaction mass (propulsive mass) that is ejected, typically with very high speed, from a rocket engine to produce thrust, and thus provide spacecraft propulsion. Each rocket type requires different kind of propellant: chemical rockets require propellants capable of undergoing exothermic chemical reactions, which provide the energy to accelerate the resulting gases through the nozzle.Interbeat interval: Interbeat interval is a scientific term used in the study of the mammalian heart.
(1/1037) Respiratory symptoms among glass bottle workers--cough and airways irritancy syndrome?
Glass bottle workers have been shown to experience an excess of respiratory symptoms. This work describes in detail the symptoms reported by a cohort of 69 symptomatic glass bottle workers. Symptoms, employment history and clinical investigations including radiology, spirometry and serial peak expiratory flow rate records were retrospectively analyzed from clinical records. The results showed a consistent syndrome of work-related eye, nose and throat irritation followed after a variable period by shortness of breath. The latent interval between starting work and first developing symptoms was typically 4 years (median = 4 yrs; range = 0-28). The interval preceding the development of dysponea was longer and much more variable (median = 16 yrs; range = 3-40). Spirometry was not markedly abnormal in the group but 57% of workers had abnormal serial peak expiratory flow rate charts. Workers in this industry experience upper and lower respiratory tract symptoms consistent with irritant exposure. The long-term functional significance of these symptoms should be formally investigated. (+info)
(2/1037) Fine particulate air pollution, resuspended road dust and respiratory health among symptomatic children.
The short-term association of particulate air pollution with peak expiratory flow rate (PEF) and respiratory symptoms was examined. Forty-nine children with chronic respiratory symptoms aged 8-13 yrs were followed daily for six weeks in spring, 1995, in Kuopio, Finland. Daily concentrations of particulate material with a 50% cut-off aerodynamic diameter < or = 10 microm and < or = 2.5 microm (PM10 and PM2.5, respectively), black carbon, and the number concentrations of particles from 0.01-10 microm diameter were measured. During the study period, PM10 were mainly resuspended soil and street dust, and the concentration was estimated using aluminum content of PM10 samples. No consistent effect of particles was found as the associations varied by lag. Of the lags examined, only 1-day lagged PM2.5 was statistically significantly associated with morning PEF (beta=-1.06, SE=0.52 (per interquartile increase in pollutant)). Evening PEF was significantly associated with the 1-day lagged number of particles in the size range 0.1-1.0 microm (beta=-1.56, SE=0.72). One-day lagged PM10, PM2.5-10, PM2.5 and resuspended PM10, and 4-day average of PM2.5 were significantly associated with increased risk of cough. Given the short duration of the study, separating the effects of different types of particles was difficult. The present study demonstrates the highly variable size and number distribution and chemical composition of particles in Finland, and underlines the importance of measuring the size and chemical composition of particles to determine which types of particles are associated with health effects. (+info)
(3/1037) Airway inflammatory response to ozone in subjects with different asthma severity.
The aim of this study was to evaluate whether ozone exposure induces a similar airway inflammatory response in subjects with different degrees of asthma severity. Two groups of asthmatic subjects were studied: seven with intermittent mild asthma not requiring regular treatment (group A); and seven with persistent mild asthma requiring regular treatment with inhaled corticosteroids and long-acting beta2-agonists (group B). All subjects were exposed, in a randomized cross-over design, to air or O3 (0.26 parts per million (ppm) for 2 h with intermittent exercise); subjects in group B withdrew from regular treatment 72 h before each exposure. Before the exposure, and 1 and 2 h after the beginning of the exposure they performed a pulmonary function test, and a questionnaire was completed to obtain a total symptom score (TSS). Six hours after the end of the exposure, hypertonic saline (HS) sputum induction was conducted. Sputum cell percentages, eosinophil cationic protein (ECP) and interleukin (IL)-8 concentrations in the sputum supernatant were measured. TSS significantly increased and forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) significantly decreased after O3 exposure in comparison with air exposure in group A, whereas no changes were observed in group B except for a significant decrement of FEV1 2 h after the beginning of O3 exposure. Sputum neutrophil percentage was significantly higher after O3 exposure than after air exposure in both groups (Group A: 70.2% (28-87) versus 26.6% (8.6-73.2); Group B: 62.1% (25-82.4) versus 27.9% (14.4-54)). IL-8 was higher in sputum supernatant collected 6 h after O3 exposure than after air, only in group A. No change due to O3 has been found in sputum eosinophil percentage and ECP concentration in both groups. In conclusion, the degree of airway response to a short-term exposure to ozone is different in subjects with asthma of different severity. The available data do not allow elucidation of whether this difference depends on the severity of the disease or on the regular anti-inflammatory treatment. (+info)
(4/1037) As-required versus regular nebulized salbutamol for the treatment of acute severe asthma.
Current British guidelines for the administration of beta2-agonists in acute severe asthma recommend regular nebulized therapy in hospitalized patients, followed by as-required (p.r.n.) use via hand-held devices after discharge. Since beta2-agonists do not possess anti-inflammatory activity in vivo, and are thus unlikely to influence the rate of recovery from an asthma exacerbation, it was hypothesized that patients given the short-acting beta2-agonist salbutamol on an as-required basis after admission to hospital would recover as quickly as those on regular treatment, but with potential reductions in the total dose delivered. Forty-six patients with acute severe asthma were randomly assigned to either regular prescriptions of nebulized salbutamol or to usage on a p.r.n. basis, from 24 h after hospital admission. The primary outcome measures were length of hospital stay, time to recovery, and frequency of salbutamol nebulization from 24 h after admission to discharge. Secondary outcome measures were treatment side-effects (tremor, palpitations), and patient satisfaction. Length of hospital stay was reduced in those patients allocated to p.r.n. salbutamol (geometric mean (GM) 3.7 days) versus regular salbutamol (GM 4.7 days). Time taken for peak expiratory flow to reach 75% of recent best was the same in both groups. There was a highly significant reduction in the number of times nebulized therapy was delivered to the p.r.n. group (GM 7.0, range 1-30) compared with the regular treatment group (GM 14.0, range 4-57; p=0.003; 95% confidence interval for ratio of GMs 1.29-3.09). In addition, patients reported less tremor (p=0.062) and fewer palpitations (p=0.049) in the p.r.n. group. Of the patients in the p.r.n. group who had received regular nebulized therapy on previous admissions (n=12), all preferred the p.r.n. regimen. Prescribing beta2-agonists on a p.r.n. basis from 24 h after hospital admission is associated with reduced amount of drug delivered, incidence of side-effects, and possibly length of hospital stay. This has implications for the efficient use of healthcare resources. (+info)
(5/1037) Acute saline infusion reduces alveolar-capillary membrane conductance and increases airflow obstruction in patients with left ventricular dysfunction.
BACKGROUND: Impaired alveolar-capillary membrane conductance is the major cause for the reduction in pulmonary diffusing capacity for carbon monoxide (DLCO) in heart failure. Whether this reduction is fixed, reflecting pulmonary microvascular damage, or is variable is unknown. The aim of this study was to assess whether DLCO and its subdivisions, alveolar-capillary membrane conductance (DM) and pulmonary capillary blood volume (Vc), were sensitive to changes in intravascular volume. In addition, we examined the effects of volume loading on airflow rates. METHODS AND RESULTS: Ten patients with left ventricular dysfunction (LVD) and 8 healthy volunteers were studied. DM and Vc were determined by the Roughton and Forster method. The forced expiratory volume in 1 second (FEV1), vital capacity, and peak expiratory flow rates (PEFR) were also recorded. In patients with LVD, infusion of 10 mL. kg-1 body wt of 0.9% saline acutely reduced DM (12.0+/-3.3 versus 10.4+/-3.5 mmol. min-1. kPa-1, P<0.005), FEV1 (2.3+/-0.4 versus 2.1+/-0.4 L, P<0.0005), and PEFR (446+/-55 versus 414+/-56 L. min-1, P<0.005). All pulmonary function tests had returned to baseline values 24 hours later. In normal subjects, saline infusion had no measurable effect on lung function. CONCLUSIONS: Acute intravascular volume expansion impairs alveolar-capillary membrane function and increases airflow obstruction in patients with LVD but not in normal subjects. Thus, the abnormalities of pulmonary diffusion in heart failure, which were believed to be fixed, also have a variable component that could be amenable to therapeutic intervention. (+info)
(6/1037) Exhaled nitric oxide; relationship to clinicophysiological markers of asthma severity.
Bronchial asthma is an airway disorder associated with bronchial hyperresponsiveness, variable airflow obstruction and elevated levels of nitric oxide (NO) in exhaled air. The variables all reflect, in part, the underlying airway inflammation in this disease. To understand their interrelationships we have investigated the relationship between exhaled NO levels and clinicophysiological markers of asthma severity. Twenty-six steroid naive atopic asthmatics participated in the analysis. All were given diary cards and were asked to record their peak expiratory flow (PEF) rates twice daily together with their asthma symptom scores and beta-agonist use. Diary cards were collected 2 weeks later and measurements of exhaled NO levels, FEV1 and histamine bronchial hyperreactivity (PC20 histamine) were undertaken. Exhaled NO levels were significantly higher in our study population than in normal control subjects and correlated negatively with PC20 histamine (r = -0.51; P = 0.008) and positively with PEF diurnal variability (r = 0.58; P = 0.002), but not with symptom scores, beta-agonist use of FEV1 (%). We conclude that a significant relationship exists between exhaled NO levels and the two characteristic features and markers of asthma severity, namely bronchial hyperreactivity and PEF diurnal variability. The lack of correlation between symptom score and beta-agonist use, of FEV1 (%) predicted and exhaled NO suggests that these measures are reflective of differing aspects of asthma. (+info)
(7/1037) Time course of respiratory decompensation in chronic obstructive pulmonary disease: a prospective, double-blind study of peak flow changes prior to emergency department visits.
The aim of this study was to look at changes in peak expiratory flow rates (PEFR) prior to emergency department visits for decompensated chronic obstructive pulmonary disease (COPD). It was designed as a prospective, double-blind study at the Albuquerque Veterans Affairs Medical Center. Twelve patients with an irreversible component of airflow obstruction on pulmonary function tests were assessed. At entry, all subjects were instructed in the use of a mini-Wright peak flow meter with electronic data storage. They then entered a 6-month monitoring phase in which they recorded PEFR twice daily, before and after bronchodilators. The meter displays were disabled so that the patients and their physicians were blinded to all values. Medical care was provided in the customary manner. Patients were considered to have respiratory decompensation if they required treatment for airflow obstruction in the Emergency Department (ED) and no other causes of dyspnea could be identified. Simple linear regression was used to model changes in PEFR over time. The 12 subjects had 22 episodes of respiratory decompensation during 1741 patient-days of observation. Two episodes could not be analysed because of missing values. Ten episodes in seven subjects were characterized by a significant linear decline in at least one peak flow parameter prior to presentation. The mean rates of change for the four daily parameters varied from 0.22% to 0.27% predicted per day (or 1.19 to 1.44 1 min-1 day-1). The average decrement in these parameters ranged from 30.0 to 33.8 1 min-1 (or 18.6%-25.9% of their baseline values). No temporal trends were found for the 10 episodes occurring in the other five subjects. We concluded that respiratory decompensation is characterized by a gradual decline in PEFR in about half of cases. Future studies should be done to elucidate the mechanisms of respiratory distress in the other cases. (+info)
(8/1037) A comparative study of the effects of ketotifen, disodium cromoglycate, and beclomethasone dipropionate on bronchial mucosa and asthma symptoms in patients with atopic asthma.
Asthma is a chronic inflammatory disorder of the airways that is characterized by infiltration of many inflammatory cells into the bronchial mucosa. We compared the effects of ketotifen, disodium cromoglycate (DSCG), and beclomethasone dipropionate (BDP) on inflammatory cells in the bronchial mucosa and on the asthma symptoms of patients with atopic asthma. In this 12-week parallel study, 32 patients were randomly allocated to either the ketotifen group (2 mg day-1, n = 13), DSCG group (8 mg day-1, n = 9) or BDP (400 micrograms day-1, n = 10). Each subject recorded daily asthma symptoms and peak expiratory flow (PEF). Before and after treatment, pulmonary function and bronchial responsiveness to methacholine were evaluated, and fibreoptic bronchoscopy and biopsy were performed before and after treatment. Biopsy specimens were obtained by bronchoscopy. We performed immunohistochemistry using specific monoclonal antibodies for activated eosinophils (EG2), mast cells (AA1), and T cells (CD3, CD4, and CD8). Our clinical findings showed significant improvement in symptom score and bronchial responsiveness (P < 0.01) each) in all groups. Both the DSCG and the BDP groups had significantly better symptom scores than the ketotifen group (P < 0.05, both groups). PEF significantly increased in the DSCG group in comparison to the ketotifen (P < 0.01) and BDP (P < 0.05) groups, FEV1% increased significantly in the DSCG (P < 0.01) and BDP (P < 0.05) groups in comparison to the ketotifen group. Compared with their baseline values, treatment significantly decreased EG2+ activated eosinophils, and CD3+ and CD4+ T cells, in each group (P < 0.01). Both the DSCG (P < 0.05) and the BDP groups (P < 0.01) exhibited significant decreases in AA1+ mast cell count, but this was not observed in the ketotifen group. Comparing before- and after-treatment values, only the DSCG group exhibited a significant decrease in the number of CD8+ T cells (P < 0.01). Ketotifen, DSCG, and BDP all showed anti-inflammatory activity as determined by examination of the bronchial mucosa of asthmatic patients; and both the DSCG and BDP groups had better clinical responses than the ketotifen group. (+info)