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Relative efficacy of nebulised ipratropium bromide and fenoterol in acute severe asthma.

In a double-blind, randomised, controlled clinical trial of 145 patients with acute asthma, the efficacy of nebulised 4-hourly ipratropium bromide plus 4-hourly fenoterol (group I, 50 patients), 2-hourly fenoterol (group II, 50 patients) and 4-hourly fenoterol (group III, 45 patients) was assessed. All patients received an optimal infusion of aminophylline and 81 patients (27 in each group) received hydrocortisone for clinical indications. It was found that cholinergic side-effects in group I were not more common than in group II. Tremor was more common in group II. Assessment of bronchodilator efficacy was confined to the 81 patients whose therapy included hydrocortisone. Peak expiratory flow rate, forced expiratory volume in 1 second, and forced vital capacity were expressed as a percentage of predicted for each individual and the mean values for each group plotted. It was found that the response rate, as assessed by the area under the curve, was significantly more rapid in group I compared with both group II (P less than 0.001) and group III (P less than 0.005). These findings were consistent for all three lung function measurements. However, there was no significant difference in the responses between group II and group III. It is concluded that adding ipratropium bromide to conventional regimens is likely to benefit patients with acute asthma.

Acute Disease↗

Continuous intercostal nerve block versus epidural morphine for postthoracotomy analgesia.

Twenty patients undergoing elective thoracotomy were randomized into two groups, receiving either lumbar epidural morphine (n = 10) or continuous extrapleural intercostal nerve block (n = 10). Subjective pain relief was assessed on a linear visual analogue scale. Pulmonary function (peak expiratory flow rate, forced expiratory volume in 1 second, and forced vital capacity) was measured on the day before operation and daily for 4 days after operation. Pulse oximetry monitoring was used to determine the incidence of hypoxemia. No significant difference was observed between the groups concerning pain relief (except at 28 hours, in favor of the intercostal nerve block group), respiratory performance, or arterial oxygen saturation. Vomiting, pruritus, and urinary retention occurred only in the epidural group, whereas nausea occurred significantly less frequently in the extrapleural group. We conclude that after thoracotomy continuous extrapleural intercostal nerve block is as effective as lumbar epidural morphine in reducing postoperative pain and restoring pulmonary mechanics. Because of the significantly lower complication rates we favor continuous extrapleural intercostal nerve block for postthoracotomy analgesia.

Adult↗

Clinical trial efficacy: what does it really tell you?

The primary goal of most clinical trials is an evaluation of the efficacy of the drug being evaluated. Therefore, it is important to understand if study outcomes are a true reflection of a drug's "real-life" effectiveness. Clinical trials generally evaluate three types of outcomes: subjective, objective, and health-related. Clinical trials that use subjective measures as endpoints usually evaluate outcomes such as symptom scores, the need for rescue medication, and quality-of-life measures. The majority of clinical trials rely on objective measures to test the efficacy of asthma medications. These include lung function (peak expiratory flow rate, forced expiratory volume at one second [FEV1]), level of bronchial hyperresponsiveness (methacholine challenge or exercise challenge), and markers of inflammation (exhaled nitric oxide, sputum eosinophils, bronchoalveolar lavage, and bronchial biopsy). FEV1 remains the gold standard of efficacy measures; however, in pediatrics, where FEV1 values are often within the normal range, re-adjustment of what constitutes various levels of asthma severity should occur. Occasionally, studies will include an assessment of health outcomes, either as a primary or secondary measure, during the course of the study. Commonly measured health outcomes include a reduction in need for rescue systemic glucocorticoids, a reduction in the need for emergent asthma care, a reduction in asthma hospitalizations, and a reduction in asthma deaths. Studies designed to assess impact of treatment regimens on morbidity and mortality remain a high priority, as do studies designed to predict response to current asthma therapies.

Anti-Asthmatic Agents↗

Minimal access surgery for cholelithiasis induces an attenuated acute phase response.

BACKGROUND: Some benefits of laparoscopic (LC) and minilaparotomy (MC) cholecystectomy may reflect attenuation of the acute phase response. The authors examined components of this response. METHODS: Patients were randomized to LC (n = 11) or MC (n = 11). C-reactive protein (CRP), alpha-1-antitrypsin (AAT), retinol-binding protein (RBP), transferrin, and albumin were measured preoperatively and on postoperative days 1, 2, 4, and 7. Interleukin-1 receptor antagonist (IL-1ra), IL-6, and tumor necrosis factor (TNF-alpha) were measured more frequently perioperatively. Peak expiratory flow rate, forced expiratory volume in 1 second, and forced vital capacity were measured daily. RESULTS: The IL-6 increase was more persistent and marked in the MC patients from hour 8 to day 7 postoperatively (P < 0.05). Alterations in CRP, AAT, and albumin were similar. Postoperative deficits of respiratory function correlated with the magnitude of acute phase protein alteration. CONCLUSIONS: Minimal access surgery induces an acute phase response that is less prominent after a laparoscopic technique.

Acute-Phase Proteins↗

The effect of preoperative methylprednisolone on pulmonary function and pain after lung operations.

Thirty-six patients undergoing elective thoracotomy with pulmonary resection with the use of combined epidural and general anesthesia were randomized into a double-blind study to receive a single intravenous preoperative dose of methylprednisolone 25 mg/kg body weight or a placebo (saline solution). Postoperative pain relief consisted of epidural morphine 4 mg and paracetamol 1 gm three times a day for 4 days. Postoperative pulmonary function (peak expiratory flow rate, forced expiratory volume in first second, forced vital capacity) was evaluated on days 1, 2, 3, 4, and 7 and after 1 month. The value obtained after 1 month served as the control value. Pain score at rest and during cough was evaluated after 4 and 8 hours and on days 1, 2, 3, and 4. Pulmonary function was reduced after operation to the same degree in the steroid and placebo group: 42% versus 41% for forced expiratory volume in first second and 38% versus 39% for forced vital capacity, compared with control values after 1 month. Pain score was reduced in the steroid group after 4 hours and on day 1 during rest and after 4 and 8 hours and on day 2 during cough, compared with results in the placebo group (p < 0.05). In the steroid group three patients underwent reoperation because of leakage through the chest wall incision. In conclusion, administration of a single preoperative dose of methylprednisolone did not affect the postoperative reduction in pulmonary function after thoracotomy despite attenuated pain response, and the results do not warrant steroid administration before lung operation.

Adult↗

Reversible T-wave abnormality in severe acute asthma: an electrocardiographic sign of severity.

Reversible electrocardiographic (ECG) abnormalities are well recognized in severe acute asthma. Inferior lead T-wave abnormalities have only rarely been reported, and their frequency and significance have not been well documented. We studied 70 consecutive patients with severe acute asthma on admission to hospital and during recovery, in order to examine the frequency and natural history of such changes and to document their relationship to the severity of the attack. Twenty-two patients (34%) had inferior lead T-wave inversion on ECGs performed within 1 h of admission (group 1), whereas the rest did not (group 2). Apart from sinus tachycardia this was the most common ECG abnormality. Patients with inferior T-wave inversion were found to have more severe asthma in terms of degree of pulsus paradoxus, peak expiratory flow rate, forced expiratory volume in 1 s and arterial blood oxygen tension. Ten group 1 and ten group 2 patients underwent two-dimensional echocardiography during the acute phase of their illness and during recovery. Six (60%) group 1 patients showed echocardiographic evidence of right ventricular pressure overload compared with only one (10%) patient in group 2 (P less than 0.02). Following recovery, voluntary hyperventilation and exercise testing in ten group 1 patients failed to reproduce the ECG changes seen on admission. Reversible inferior lead T-wave abnormalities may occur in the severe acute asthma and appear to be related to the severity of the attack.

Acute Disease↗

Failure of rectal diclofenac to augment opioid analgesia after cholecystectomy.

The analgesic efficacy of a single 100-mg suppository of diclofenac sodium given after elective cholecystectomy was studied in 30 healthy patients in a double-blind randomised controlled manner. The mean 24-hour postoperative morphine consumption of the placebo group and the diclofenac group was similar (45 mg). Analysis of the cumulative hourly morphine consumption from the patient-controlled analgesia system failed to show any statistically significant differences between the groups. Peak expiratory flow rate, forced expiratory volume at 1 second and forced vital capacity decreased 24 hours after operation to less than 50% of pre-operative values in both groups. Subjective experiences of pain, nausea and drowsiness assessed by linear analogue scoring were similar in both groups.

Administration, Rectal↗

Efficacy of acupuncture in asthma: systematic review and meta-analysis of published data from 11 randomised controlled trials.

Contradictory results from randomised controlled trials of acupuncture in asthma suggest both a beneficial and detrimental effect. The authors conducted a formal systematic review and meta-analysis of all randomised clinical trials in the published literature that have compared acupuncture at real and placebo points in asthma patients. The authors searched for trials published in the period 1970-2000. Trials had to measure at least one of the following objective outcomes: peak expiratory flow rate, forced expiratory volume in one second (FEV1) and forced vital capacity. Estimates of the standarised mean difference, between acupuncture and placebo were computed for each trial and combined to estimate the overall effect. Hetereogeneity was investigated in terms of the characteristics of the individual studies. Twelve trials met the inclusion criteria but data from one could not be obtained. Individual patient data were available in only three. Standardised differences between means ranging from 0.071 to 0.133, in favour of acupuncture, were obtained. The overall effect was not conventionally significant and it corresponds to an approximate difference in FEV1 means of 1.7. After exploring hetereogenenity, it was found that studies where bronchoconstriction was induced during the experiment showed a conventionally significant effect. This meta-analysis did not find evidence of an effect of acupuncture in reducing asthma. However, the meta-analysis was limited by shortcomings of the individual trials, in terms of sample size, missing information, adjustment of baseline characteristics and a possible bias against acupuncture introduced by the use of placebo points that may not be completely inactive. There was a suggestion of preferential publication of trials in favour of acupuncture. There is an obvious need to conduct a full-scale randomised clinical trial addressing these limitations and the prognostic value of the aetiology of the disease.

Acupuncture Therapy↗

Zafirlukast. A review of its pharmacology and therapeutic potential in the management of asthma.

Zafirlukast is a competitive and selective leukotriene receptor antagonist indicated for the prophylaxis and treatment of chronic asthma. The rationale for the development of leukotriene antagonists was based on in vitro and in vivo data demonstrating the extensive role of the cysteinyl leukotrienes C4 (LTC4), D4 (LTD4) and E4 (LTE4) in the pathogenesis of asthma. Initial data have demonstrated an improvement in pulmonary function and symptom control and a reduction in the use of short-acting inhaled beta 2-adrenoceptor agonist therapy in patients with mild to moderate asthma treated with oral zafirlukast at the recommended dosage of 20 mg twice daily. Available data also suggest that zafirlukast may significantly reduce the incidence of asthma exacerbations. Data on the comparative efficacy of zafirlukast and existing antiasthma medications are limited. Results from 2 double-blind randomised studies comparing zafirlukast 20 mg twice daily with sodium cromoglycate aerosol or dry powder inhalation reported similar efficacy for both drugs. In a comparison with inhaled beclomethasone dipropionate (0.2 to 0.25 mg twice daily), improvements in morning peak expiratory flow rate, forced expiratory volume in 1 second and daytime symptom score were significantly less with zafirlukast 20 mg twice daily for 6 weeks. However, available data suggest that patient compliance and patient preference may be greater with oral zafirlukast 20 mg twice daily than with twice-daily inhaled corticosteroid therapy. Confounding results from 2 studies preclude any clear conclusions regarding the potential steroid-sparing effect of zafirlukast at the recommended dosage of 20 mg twice daily. Furthermore, Churg-Strauss syndrome has been reported in 6 patients who were being withdrawn from oral corticosteroid therapy while receiving treatment with oral zafirlukast. It is, therefore, recommended that zafirlukast-treated patients who require a reduction in their oral corticosteroid therapy are closely monitored. Zafirlukast is generally well tolerated. Reports of elevated liver enzymes in patients receiving high dosages of zafirlukast (80 mg twice daily) preclude the use of dosages exceeding 40 mg twice daily. Careful monitoring is necessary in zafirlukast-treated patients receiving concomitant therapy with drugs such as warfarin, terfenadine and erythromycin because of the potential for drug interactions. Thus, zafirlukast is a potentially useful addition to current antiasthma therapies in patients with mild to moderate asthma. Because zafirlukast is administered orally, it may be particularly beneficial in patients poorly compliant with asthma therapy as a result of poor inhaler technique. Further investigation of the efficacy of zafirlukast is expected to more clearly define its position in the management of asthma.

Anti-Asthmatic Agents↗

Passive smoking by asthmatics: its greater effect on boys than on girls and on older than on younger children.

In 415 nonsmoking asthmatic children who were seen consecutively, asthma symptoms were more severe if the mother was a smoker than if she was a nonsmoker. This applied to both sexes but was more marked in boys than in girls. There were also other indications that sons were the more severely affected: the forced expiratory volume at 1 second, the forced expiratory flow rate during the middle half of the forced vital capacity, and the provocation concentration of histamine needed to result in a 20% decrease in the forced expiratory volume at 1 second were significantly decreased only in the sons, and lung function test results were significantly less in sons than in daughters of mothers who smoked. When the 415 children were stratified according to age, lung function improved significantly with increasing age in the children of nonsmokers; in children of smokers, by contrast, symptoms and lung function test results became progressively worse. As well, there was a correlation between these indications of asthma severity and the number of years the child had been exposed to the mother's smoke. It appeared that, compared with girls, boys were more sensitive to passive smoking, and that its adverse effect increased with age and with duration of exposure.

Adolescent↗

Clinical comparison of albuterol, isoetharine, and metaproterenol given by aerosol inhalation.

The clinical effectiveness of albuterol, isoetharine, and metaproterenol administered by aerosol inhalation at manufacturer-recommended doses was compared. A double-blind, placebo-controlled, crossover comparison of albuterol 280 micrograms, isoetharine 680 micrograms, and metaproterenol 1300 micrograms was conducted in 10 adult men with reversible, chronic pulmonary obstruction. FEV1 (forced expiratory volume at one second), FEF25-75 (forced expiratory flow rate from 25 to 75% of vital capacity), and FVC (forced vital capacity) were determined periodically for six hours after drug administration. Bronchodilator effects, adverse effects, and cost of treatments were compared. Theophylline therapy was unaltered during the study, and serum theophylline concentration was determined periodically to control for its effect on pulmonary function. Serum theophylline concentration was not used as a covariate since it resulted in minimal change in the pulmonary-function measures. The mean maximum percent change from baseline for FEV1 for each drug was superior to placebo; there were no differences among drugs. Comparing area under the curve of mean percent change in FEV1 versus time, albuterol and metaproterenol produced changes that were greater than placebo but not different from each other or isoetharine. For FEF25-75 and FVC, albuterol and metaproterenol, respectively, were superior. No pattern of adverse effects was identifiable among the four treatments. The average wholesale cost of albuterol products was approximately 1.7 times the cost of metaproterenol products. Under the conditions of this study, metaproterenol was superior to isoetharine and therapeutically equivalent to and less expensive than albuterol.

Aerosols↗

Gastro-oesophageal reflux disease in 'difficult-to-control' asthma: prevalence and response to treatment with acid suppressive therapy.

BACKGROUND: The causal association between gastro-oesophageal reflux disease (GERD) and difficult-to-control asthma is unclear. AIM: To determine the prevalence of GERD and response to proton pump inhibitor therapy in patients with difficult-to-control asthma. METHODS: Consecutive patients with difficult-to-control asthma as defined by persistent and recurrent symptoms despite on optimal asthmatic medications were recruited for the study. GERD was diagnosed by symptoms, gastroscopy and 24-h oesophageal pH monitoring. All patients were prescribed a course of lansoprazole 30 mg daily for 8 weeks. Improvement to treatment was assessed by a change in pulmonary symptom score and also by patient's subjective assessment of improvement. RESULTS: Seventeen of 30 (56.7%) patients with difficult-to-control asthma were diagnosed with GERD. Pulmonary symptom score improved significantly only in patients with GERD (35.0 to 21.0; P = 0.002). Twelve of 16 (75%) patients with GERD reported an improvement in asthma symptoms; 1 of 11 (9.1%) without GERD reported mild symptom improvement. There was no significant change in peak expiratory flow rate and forced expiratory volume. CONCLUSIONS: More than half of patients with difficult-to-control asthma were diagnosed with GERD. In these patients the severity of asthma improved significantly with potent acid suppression therapy. This underlines the critical role of acid reflux in this subset of patients with difficult-to-control asthma.

2-Pyridinylmethylsulfinylbenzimidazoles↗

[Optimal dynamic characteristics of a measuring unit of the pneumotachometer].

The dynamic error of the pneumotachometer may be reduced to the minimum through optimizing dynamic characteristics of its measuring unit. Such an optimization provides that the relative dynamic error of the instrument does not exceed - 5% when measuring the maximum volume flow rate of the forced expiration.

Adult↗

Evaluation of pulmonary mechanics in guinea pigs during respiratory anaphylaxis.

Guinea pigs sensitized to ovalbumin exhibit signs of respiratory impairment when exposed to an aerosol of the antigen. This response was investigated in anesthetized guinea pigs by determining forced pulmonary mechanics to derive peak expiratory flow rate, forced vital capacity, forced expiratory volume in 0.1 sec, maximal mid-expiratory flow rate and respiratory rate. Measurement of these parameters allows qualitative comparisons to be made with changes that are routinely determined during investigations of human asthma. Exposure of anesthetized guinea pigs to a 3% ovalbumin aerosol for 2 min produced an increase in respiratory rate, a 20% fall in peak expiratory flow rate and maximal mid-expiratory flow rate, a 50% fall in forced vital capacity and a 40% fall in forced expiratory volume in 0.1 sec. This response was reversed by aminophylline. In these respects the response appears to be similar to the acute asthmatic response in humans.

Aminophylline↗

Forced expiratory time--its reliability as a lung function test.

Three studies of factors affecting variability of forced expiratory time (FET) have been carried out. In the first, different observers or repeated measurements over a few minutes were shown to make no significant contribution to FET variability. Time of day was also relatively unimportant. In the second study, FET was shown to vary considerably more than peak flow rate, forced expiratory volumes, and mid expiratory flow rates over the course of five days. In the third study, FET was shown to correlate with other measurements of airways obstruction though the correlation coefficients were relatively low. The measurement of FET is thought to be too variable to be of practical use as a screening test for small airways disease, though its clinical value is not questioned.

Adolescent↗

Adequacy of control of asthma in a general practice. Is maximum peak expiratory flow rate a valid index of asthma severity?

OBJECTIVES: To evaluate the adequacy of control of asthma in patients attending a general practice; and to examine the validity of peak expiratory flow rate (PEFR) as an index of asthma severity in the context of general practice. DESIGN: Short-term cohort study using indices derived from two weeks of peak flow monitoring to evaluate asthma control. PARTICIPANTS: Known and newly diagnosed asthmatics aged six years or more who presented during the study period for any reason. They were enrolled if baseline forced expiratory volume in one second (FEV1) increased by 10% or more after the administration of nebulised salbutamol. Children under the age of 12 years with no initial response to bronchodilator were included if an exercise test performed on another day was positive. OUTCOME MEASURES: Peak flow criteria for "mild asthma" in the Asthma Management Plan, 1989 (Med J Aust 1989; 151: 650-653) were used as the initial definition of "adequate control". The definition of "adequate control" was modified to variability less than 20% and a minimum PEFR of 50% or more of mean predicted value. RESULTS: There was no association between variability and maximum PEFR, but variability was strongly correlated with minimum PEFR (R = -0.60; P < 0.0005). Asthma was adequately controlled in 68% of the participants. CONCLUSION: Current guidelines with respect to the peak flow indices used in the classification of the severity of asthma need to be re-evaluated and probably changed for application in general practice.

Asthma↗