Management of acute asthma in children using metered dose inhaler and small volume nebulizer. Is the increase in bronchial responsiveness or FEV1 shortly after cessation of beta2-agonists reflecting a real deterioration of the disease in allergic asthmatic patients? A comparison between short-acting and long-acting beta2-agonists. The effect of beta-blockers on ventilatory function in chronic bronchitis. Metered-dose inhalers with spacers vs nebulizers for pediatric asthma. Short-term regular beta 2-adrenergic agonists treatment is safe in mild asthmatics taking low doses of inhaled steroids. Inhaling beta(2)-agonist with heliox-driven in bronchial asthma. Labetalol, beta blockers, and acute deterioration of chronic airway obstruction.
To determine whether the administration of beta2-agonist by Metered Dose inhaler (MDI) with accessory device (AD) is a as effective as the administration of beta2-agonist by small volume nebulizers (SVN) for the treatment of acute asthma.
                A cross sectional study was conducted at Emergency Room (ER) of National Institute of Child Health (NICH), Karachi, between October 2000 to March 2001. This study included 150 children, 6 months and older with a history of wheeze and presenting with an acute asthma exacerbation. Children were categorized into mild, moderate and severe asthma according to medical scoring system. Children were assigned randomly into group A and B to receive standard dose of beta2-agonist (salbutamol) by MDI/AD (group A) or SVN (group B). Baseline characteristics and asthma severity were recorded. All variables (dyspnoea, use of accessory muscles, cyanosis, respiratory rate, heart rate, blood pressure, oxygen saturation, pulsus paradoxus, and wheeze) and Peak Expiratory Flow Rate (PEFR) in children 5 years and older, were determined at pre and post inhalation therapy.
                Both groups did not differ in demographic characteristics. There were no significant differences in outcome measures. In children treated with MDI/ADs and SVNs. PEFR increased significantly in both the groups after completion of treatment, but PEFR was not statistically significant when compared in between groups.
                The data suggested that MDI/AD is an effective alternative to nebulizer for the treatment of children with acute asthma exacerbation in the ER. Regular use of beta2-agonists might result in increased bronchial hyper-responsiveness (BHR) and decreased forced expiratory volume in 1 sec (FEV1). It has been suggested that these possible detrimental effects are not a real deterioration of the disease, but that it might be only a transient (rebound) effect shortly after discontinuing this regular use. Moreover, these effects are thought to occur especially during short-acting and not during long-acting beta2-agonists use. The aim of this study was to invest gate whether a rebound effect (a pharmacological deterioration effect diminishing after several hours) in FEV1 and PC20 (concentration of histamine causing a 20% fall in FEV1 with regard to baseline) occurred after cessation of regular use of beta2-agonists, and whether this occurred both after short-acting and long-acting beta2-agonists. Allergic asthmatic patients (n = 134) were randomly allocated to the use of a short-acting (salbutamol), a long-acting beta2-agonist (formoterol) or placebo for 12 weeks (double-blind, double-dummy). No other asthma medication was allowed, including inhaled corticosteroids. At the start and every 4 weeks later FEV and PC20 were measured, each time at least 12 h after the last doses of study medication, which is in the possible rebound period. To investigate whether a (transient) rebound effect occurred, parameters were additionally measured at least 72 h later after discontinuation of the study medication. After 12 weeks of short-acting beta2-agonist use, a drop was seen in FEV1 from 85.6 (+/- 2.21)% predicted to 78.8 (+/- 2.9)% predicted, measured 15 h (median) after the last doses of medication. This was significantly different compared to placebo. When measured 168 h (median) later FEV1 recovered to 85.5 (+/- 2.4)% predicted, comparable to baseline. PC20 decreased with -1.17 (+/- 0.44) doubling dose after 12 weeks of short-acting beta2-agonist use, measured 15 h after the last doses of medication, which was significantly different compared to placebo. However, 168 h later PC20 recovered slightly with +0.55 (+/- 0.34) doubling dose, but this value was still lower compared to placebo. In contrast, during long-acting beta2-agonist and placebo use no significant changes were seen. In conclusion, the use of short-acting beta2-agonists resulted in a transient (rebound) effect in FEV while the effects on PC20 may point to a real deterioration of the disease. Long-acting beta2-agonist and placebo use showed no changes. We conclude that a mono-therapy of short-acting and not of long-acting beta2-agonists might have deleterious effects in asthma. The effect of propranolol and atenolol on air-flow obstruction in patients with chronic bronchitis was evaluated by means of a double-blind, placebo-controlled cross-over trial. Fifteen patients with chronic bronchitis and mild air-flow obstruction, in whom there was no clinical suggestion of asthma, were studied. Two patients developed symptomatic increases in air-flow obstruction on propranolol and were withdrawn from the study. A symptomatically insignificant but statistically significant increase in air-flow obstruction was observed during treatment with both propranolol and atenolol. To determine whether the administration of beta-agonists by metered-dose inhaler (MDI) with a spacer device is as effective as the administration of beta-agonists by nebulizer for the treatment of acute asthma exacerbations in children.
                Randomized trial with two arms.
                Urban pediatric emergency department (ED) in Bronx, NY.
                Convenience sample of 152 children 2 years and older with a history of at least two episodes of wheezing presenting to the ED with an acute asthma exacerbation.
                Patients were randomly assigned to receive standard doses of a beta-agonist (albuterol) by an MDI with spacer or by a nebulizer. Dosing intervals and the use of other medications were determined by the treating physician.
                Baseline characteristics and asthma history were recorded. Asthma severity score, peak expiratory flow rate in children 5 years or older, and oxygen saturation were determined at presentation and before admission or discharge. The groups did not differ in age, sex, ethnicity, age of onset of asthma, or asthma severity score at presentation. There were no significant differences between the groups in outcomes, including mean changes in respiratory rate, asthma severity score, and peak expiratory flow rate, oxygen saturation, number of treatments given, administration of steroids in the ED, and admission rate. Patients given MDIs with spacers required shorter treatment times in the ED (66 minutes vs 103 minutes, P < .001). Fewer patients in the spacer group had episodes of vomiting in the ED (9% vs 20%, P < .04), and patients in the nebulizer group had a significantly greater mean percent increase in heart rate from baseline to final disposition (15% vs 5%, P < .001).
                These data suggest that MDIs with spacers may be an effective alternative to nebulizers for the treatment of children with acute asthma exacerbations in the ED. Regular treatment with beta 2-adrenergic agonists is controversial in bronchial asthma. To investigate whether beta 2-adrenergic agonists can be used safely if associated with low doses of inhaled steroids, for a short period, without a deterioration of asthma control, we have examined 24 mild asthmatics. In a parallel, double-blind, placebo-controlled study, 1 week of run-in and run-out period framed 3 weeks of treatment. All patients received inhaled beclomethasone dipropionate (BDP 250 micrograms t.i.d.); after 1 week, 12 patients inhaled 400 micrograms of broxaterol and 12 patients received placebo t.i.d. FVC, FEV1, PD20-FEV1 methacholine, morning and evening PEF, and PEF amplitude % mean were measured before, during, and after treatment. No significant changes were noted in patients receiving inhaled broxaterol. There were no differences in symptoms and the use of rescue medication (salbutamol spray). We conclude that short-term regular treatment with beta 2-adrenergic agonists is not associated with a deterioration in asthma control in mild asthmatics inhaling low doses of steroids. To evaluate the effectiveness of a helium-oxygen mixture (79%He- 21%O(2)) as an aerosolizing compressed gas for beta(2)-agonist therapy in patients with an asthma exacerbation.
                Twenty-four patients in the outpatient department with a mild to moderate exacerbation of asthma were enrolled. The patients were randomly divided into an experimental group (13 cases) and a control group (11 cases). The experimental group inhaled Berotec with heliox-driven, and the control group inhaled Berotec with compressed air-driven. Eight hospitalized patients in the respiratory department with severe exacerbation of asthma were enrolled. The patients inhaled Berotec with heliox-driven or compressed air-driven in a random order.
                The results of spirometric parameters and arterial blood-gas analysis were measured. In the mild to moderate asthma patients, no statistical differences between the two groups for forced vital capacity (FVC), forced expired volume in one second (FEV(1)), and expiratory flow in 50% forced vital capacity (FEF(50)) were presented. But the severe patients showed significant differences between heliox-driven and compressed air-driven for FVC, FEV(1), FEF(50) and partial pressure of oxygen (PaO(2)).
                Compared with the traditional inhalation of beta(2)-agonist therapy using compressed air-driven, the method of inhaling beta(2)-agonist with heliox-driven has more obvious benefits for those suffering from severe asthma. This is likely due to the cooperative effects between inhaling heliox on its physical gas properties and improving delivery of beta(2)-agonist in the treatment of exacerbation of severe asthma. The effects on lung function of labetalol (a combined alpha and beta adrenergic receptor blocker) and three beta adrenergic receptor blockers (propranolol, atenolol, metoprolol) have been assessed in patients with chronic airflow obstruction using a double-blind trial. With the dosages used, all drugs produced an equivalent fall of blood pressure. Propranolol was the only drug that significantly increased airways obstruction (FEV1, specific airways resistance). Following salbutamol, labetalol was associated with a significantly greater improvement of airflow than either propranolol or metoprolol. On these acute studies, the order of preference for beta blocking drugs in management of hypertension in patients with obstructive airways disease, would be labetalol, (atenolol) or (metoprolol) and then propranolol.
There is no evidence to support the use of beta2-agonists in children with acute cough who do not have evidence of airflow obstruction. There is also little evidence that the routine use of beta2-agonists is helpful for adults with acute cough. These agents may reduce symptoms, including cough, in people with evidence of airflow obstruction. However, this potential benefit is not well-supported by the available data and must be weighed against the adverse effects associated with their use.