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PubMed2001

Effect of salbutamol on lung function parameters of healthy children.

UNLABELLED: In the present study, the effect of 200 microg salbutamol compared to placebo was evaluated on lung function parameters of 37 healthy children aged 7-14 years. Salbutamol or placebo were administered, using a single blind study design, and spirometry was performed before and after 10 min of inhalation. At the time of the study, all children were symptom-free and had not suffered from any respiratory infection during the previous 4 weeks. The administration of salbutamol resulted in a significant increase of mean forced expiratory volume in 1 s (111%-115%, P<0.05), maximal expiratory flow at 50% of forced vital capacity (101%-110%, P<0.05) and maximal expiratory flow at 25 % of forced vital capacity (96%-115%, P<0.05). The administration of placebo resulted in no significant change in lung function parameters. CONCLUSION: The administration of 200 microg salbutamol results in the occurrence of a small but significant bronchodilation in healthy, non-asthmatic children.

Adolescent↗
PubMed1978

The refractory period after exercise-induced asthma: its duration and relation to the severity of exercise.

A study was carried out to determine whether an episode of exercise-induced asthma (EIA) is followed by a refractory period and to assess the factors that affect it. Nine children, 9 to 14 years of age, were studied during repeated, paired exercise tests on a treadmill. Respiratory function was assessed by measuring peak expiratory flow rate before and after exercise. Changes were related to measured uptake of O2 during exercise. When paired tests were at a constant metabolic load, the severity of EIA was relatively constant in the first test of each pair, but it diminished in the second tests as the interval between tests decreased. The ability to bronchoconstrict fully was recovered within 4 hours after a test. When tests at varying metabolic loads were followed after 30 min by tests at a constant load, the severity of EIA increased in proportion to the load in the first test of each pair. In the second tests it was inversely related to that which occurred in the first tests. These results were compatible with the suggestion that the development of EIA requires the release of a stored mediator or enzyme precursor.

Adolescent↗
PubMed1976

Lung function among black and white children.

Racial differences in ventilatory lung function were evaluated in a community study of 393 children (158 blacks, 235 whites). Mean forced vital capacity was 18 per cent larger in nonsmoking white males than in nonsmoking black males, and 11 per cent larger in nonsmoking white females than in nonsmoking black females. Similar differences were observed for the 1-sec forced expiratory volume and for the maximal expiratory flow at 50 per cent of the vital capacity. However, when adjusted for lung size (on the basis of forced vital capacity), 1-sec forced expiratory volume and maximal expiratory flow at 50 per cent of the forced vital capacity were larger in the black children compared to the white children. Lung function prediction equations based on race, sex, age, height and weight are presented for healthy nonsmoking children; these allow for an evaluation of normal lung function in both black and white children.

Adolescent↗
PubMed1994

Normal values for single exhalation diffusing capacity and pulmonary capillary blood flow in sitting, supine positions, and during mild exercise.

Previous approaches to the measurements of pulmonary diffusing capacity (DL) and pulmonary capillary blood flow (QC) utilized either the rebreathing or the single inhalation technique in conjunction with radioisotope gas and mass spectrometry. In the present study, we utilized a newly developed rapid infrared analyzer in conjunction with the slow single exhalation technique on 100 healthy volunteers to establish normal values for DL and QC under sitting, supine, and exercise conditions. The exercise level was determined by a target heart rate: HRex = ([HRmax - HRrest]/3) + HRrest. Prediction equations based on regressions on age, sex, height, or weight were then computed for sitting, supine, and exercise values. We found that mean DL and QC increased by approximately 12 percent and 8 percent, respectively, from sitting to supine posture, and by approximately 30 percent and 100 percent, respectively, from sitting (rest) to mild exercise. These results provided a database for further studies in the single exhalation method in various clinical settings.

Acetylene↗
PubMed1984

The comparative beta-adrenoceptor blocking effects of penbutolol, atenolol and sustained-release metoprolol in healthy volunteers.

The effects of penbutolol (40 mg), atenolol (100 mg) and sustained-release metoprolol (metoprolol SA) (200 mg) upon heart rate (HR) and blood pressure (BP) at rest and during bicycle ergometer exercise, have been compared in 12 healthy young men using a double-blind crossover design. Measurements of each drug's effect were made before and at 3, 10 and 24 h after a single dose, and again at 24 h after the last of seven consecutive daily doses. Resting HR and systolic BP were reduced to an equivalent extent by all three drugs. During the third minute of exercise, the effects of penbutolol and atenolol upon HR and systolic BP were consistently similar and greater than those of metoprolol SA.

Adolescent↗
PubMed1983

Pafenolol, a highly selective beta 1-adrenoceptor-antagonist, in asthmatic patients: interaction with terbutaline.

Pafenolol, a new beta 1-adrenoceptor antagonist, has been shown in animals to be more selective for beta 1-adrenoceptors than metoprolol. It was studied in asthmatic patients to evaluate whether it was more selective with respect to circulatory effects and especially whether this selectivity influenced bronchial muscle tone less than metoprolol, which has been shown to have beta 1-adrenoceptor selectivity similar to that of atenolol. Intravenous pafenolol (5 mg and 7.5 mg), metoprolol (15 mg), and saline were given double-blind at random and thereafter four increasing doses of terbutaline were given intravenously to seven asthmatic patients with reproducible reversibility of airways obstruction. After the terbutaline dose-response curve was determined, terbutaline was inhaled three times in increasing doses. A separately reported exercise study in the same patients showed that 5 mg pafenolol and 15 mg metoprolol were equipotent with respect to beta 1-adrenoceptor blockade, whereas 7.5 mg pafenolol tended to increase the blockade. The reflex tachycardia on terbutaline stimulation after pafenolol was greater than after metoprolol due to less blockade of beta 2-adrenoceptors in peripheral blood vessels. The bronchial effect of pafenolol was equal to that of saline, but there was a difference between the terbutaline dose-response curves after pafenolol and metoprolol that caused a rightward shift of the dose-response curve. Thus, pafenolol was shown to be more beta 1-selective than metoprolol.

Adrenergic beta-Antagonists↗
PubMed1993

Pharmacodynamic effects of inhaled dry powder formulations of fenoterol and colforsin in asthma.

The airway and tremor response and cardiovascular and hypokalemic effects of single doses of inhalative fenoterol dry powder capsules (0.4 mg) were compared with the fenoterol metered dose inhaler (0.4 mg) and colforsin (forskolin) dry powder capsules (10.0 mg), a direct activator of the adenylate cyclase system, in 16 patients with asthma. Subjects (FEV1 < or = 60% predicted) were investigated in a randomized, double-masked, placebo-controlled, four-period, crossover trial for a 120 minute period. All active drugs caused a significant increase in specific airway conductance (p < 0.05); the order of potency (mean +/- SEM maximum increase from baseline) was fenoterol metered dose inhaler (0.51 +/- 0.06 sec-1 x kPa-1), fenoterol dry powder capsules (0.49 +/- 0.07), and colforsin dry powder capsules (0.30 +/- 0.03). A marked increase in finger tremor amplitude resulted after fenoterol metered dose inhaler only (62.93% +/- 10.21%; p < 0.05) in contrast to fenoterol dry powder capsules (15.84% +/- 4.35%; p < 0.05) and colforsin dry powder capsules (12.87% +/- 10.44%; p > 0.05). A decrease in plasma potassium was found after fenoterol (metered dose inhaler > dry powder capsules; p < 0.05). In conclusion, fenoterol dry powder capsules caused less tremor response and hypokalemic effects than the metered dose inhaler, although the bronchodilator capacity was similar. Colforsin dry powder capsules resulted in a measurable bronchodilatation in patients with asthma.

Administration, Inhalation↗
PubMed1975

Spiroergometric and telemetric investigations during the XXI International Stoke Mandeville Games 1972 in Heidelberg.

Spiroergometric and telemetric investigations were carried out on 100 paralysed athletes during the XXI International Stoke Mandeville Games in Heidelberg, 1972. The technical and organisational difficulties in carrying out these measurements were engendered by the disabilities of subjects. The maximum oxygen uptake observed and the oxygen pulse were lower than in non-disabled persons. There were no differences in the peak heart rates (180-200 beats/min.) as compared with non-disabled athletes during particular competition situations. Sports characterised by quickness, dexterity and strength are not able to train the cardiopulomnary system substantially. Swimming is recommended as beneficial. Psychological and training physiological considerations suggest that long-distance wheelchair races should be adopted as a Stoke Mandeville event.

Adult↗
PubMed1975

Pulmonary function in asthmatic children during thalassotherapy.

In 39 asthmatic children, 5-14 years of age, sent to the Kinderkurheim Satteldüne for a 6 week course of thalassotherapy, the following pulmonary function studies were tested serially: Vital capacity (VC), one-second forced expiratory volume (FEV1), maximal mid-expiratory flow rate (MMFR) and peak flow rate (PFR). Results expressed as mean values per week of the group as a whole, showed subnormal results at initial testing in all 4 parameters measured. Improvement followed rapidly with the final level generally achieved during week 2. However, statistical analysis showed the differences between the initial and each of the subsequent values to be insignificant with one exception in the FEV1 values. Thus the clinical improvement observed in most patients during thalassotherapy could not be substantiated by pulmonary function tests.

Adolescent↗
PubMed1975

[Study of clinical pharmacology of acebutolol in 5 asthmatic patients].

Respiratory function (V.E.M.S.-C.V.) and cardiovascular function (pulse and blood pressure) were studied in 5 asthmatic patients who were given isoprenaline aerosols after I.V. injection of normal saline solution (in the first step) and acebutolol (in the second step). The respiratory function is not disturbed by acebutolol. On the other hand, the cardio-accelerating effect of isoprenaline was not neutralized by acebutolol during these two assays, but significantly reduced.

Acebutolol↗
PubMed1987

The effect of an oral leukotriene D4 antagonist L-649,923 on the response to inhaled antigen in asthma.

We have compared the effects of the leukotriene (LT) D4 antagonist L-649,923 and placebo on the airway response to antigen challenge in eight men with mild asthma known to have both an early and late response to inhaled antigen. Subjects ingested 1000 mg of L-649,923 or placebo in a randomized, double-blind protocol and, two hours later, inhaled the dose of antigen known to induce a 20% fall in FEV1. Pulmonary function (specific conductance, FEV1, peak expiratory flow rate, and maximal flow at 25% of vital capacity) was measured at intervals before and up to 9 hours after antigen. FEV1 fell in one subject after L-649,923 ingestion. L-649,923 in the other seven subjects caused no change in baseline pulmonary function, a small reduction in the early response to antigen for FEV1, peak expiratory flow rate, and maximal flow at 25% of vital capacity but not for specific airway conductance (six subjects only) and no effect on the late response. The mean maximum fall in FEV1 in the early response was 1.35 L after L-649,923 ingestion and 1.78 after placebo ingestion. This relatively small degree of protection by L-649,923 suggests either that L-649,923 is not a sufficiently potent antagonist to diminish the effect of endogenous LTD4 in vivo or that LTD4 does not play a major role in the airway response to antigen challenge.

Administration, Inhalation↗
PubMed1984

Upper respiratory tract infections and airway reactivity in normal and asthmatic subjects.

To assess the effect of an upper respiratory tract infection (URTI) on airway reactivity, histamine inhalation tests (HITs) were performed prospectively in 44 nonsmoking asthmatic (14) and nonasthmatic (30) volunteers. Fifteen of the subjects developed an URTI during the following 4 months. Pulmonary function-forced expiratory volume in one second (FEV1), maximal midexpiratory flow rates (MMEFR) and maximal flow at 50% vital capacity (V50), and HITs, were studied at onset and 2, 3, and 4 wk after infection. There were no significant changes in pulmonary function during the total study period. For the 15 subjects, the mean provocative concentration of histamine causing a 20% fall in FEV1, (PC20H) was 8.73 mg/ml prior to onset of URTI, and at 1, 2, 3, and 4 wk after URTI was 7.97, 8.68, 8.13, and 8.61 mg/ml. These were not significantly different for the group as a whole, nor for the subgroups of asthmatics and nonasthmatics. Small changes in PC20H outside the normal range of variability occurred in 5 of 15 subjects. These were short-lived and no predictive factor for change in PC20H was identified in this group. Thus, URTI was not associated with significant changes in PC20H in this group of asthmatic and nonasthmatic subjects.

Adult↗
PubMed2004

Increase in alveolar nitric oxide in the presence of symptoms in childhood asthma.

STUDY OBJECTIVES: To determine respective contributions of alveolar and proximal airway compartments in exhaled nitric oxide (NO) output (QNO) in pediatric patients with asthma and to correlate their variations with mild symptoms or bronchial obstruction. PATIENTS AND DESIGN: In 15 asthmatic children with recent mild symptoms, 30 asymptomatic asthmatic children, and 15 healthy children, exhaled NO concentration was measured at multiple expiratory flow (V) rates allowing the calculation of alveolar and proximal airway contributions in QNO, using two approaches, ie, linear and nonlinear models. MEASUREMENTS AND RESULTS: Asymptomatic and recently symptomatic patients were not significantly different regarding FEV(1) and maximum V between 25% and 75% of FVC (MEF(25-75)): FEV(1), 93.3 +/- 13.4% vs 90 +/- 7.5%; MEF(25-75), 70 +/- 22% vs 68 +/- 28% of predicted values, respectively (mean +/- SD). Maximal airway QNO output was significantly higher in recently symptomatic vs asymptomatic patients (p < 0.0001), and in asymptomatic patients vs healthy children (p < 0.02): 134 +/- 7 nl/min, 55 +/- 43 nl/min, and 19 +/- 8 nl/min, respectively. In a multiple regression analysis, variables that influenced airway QNO output were symptoms (p < 0.0001) and distal airway obstruction as assessed by MEF(25-75) (p < 0.05). Alveolar NO concentration (FANO) was significantly (p < 0.03) higher in recently symptomatic than in patients without symptoms, whereas it was not significantly different between asymptomatic patients and healthy children: 7.2 +/- 2.4 parts per billion (ppb), 5.5 +/- 2.7 ppb, and 4.2 +/- 2.0 ppb, respectively. CONCLUSIONS: An increase in FANO was observed in the presence of symptoms, and proximal airway NO output was correlated with distal obstruction during asthma.

Asthma↗