Use of anticholinergic bronchodilation in children

Asthma management issues in infancy and childhood

The prevalence of asthma has been increasing worldwide over the past 2 decades, especially the prevalence of childhood asthma. Currently, the prevalence of childhood asthma is around 3-20% in different countries based on the report from the International Study of Asthma and Allergies in Children (ISAAC). Asthma in childhood is predominantly an extrinsic asthma. In general, countries in the coastal, temperate, and subtropical zones have the highest prevalence of mite- and cockroach-sensitive asthma. Countries in the sub-arctic or semi-arid areas have a lower prevalence of childhood asthma, mostly associated with sensitization to pet dander, moulds, and pollens. Many genes have been linked to asthma in different ethnic populations. A global consensus for the management of asthma in adults and children >5 years of age has been made possible in the Global Initiative for Asthma (GINA) guidelines, where a step-wise management program using inhaled medication with and without oral anti-inflammatory drugs is recommended. The management of asthma in children <5 years of age remains inconclusive. Recent studies suggest that inherited susceptibility associated with risk factors from the prenatal and postnatal environment is likely to promote allergic sensitization and development of asthma. Consequently, early prevention of prenatal sensitization in utero and environmental control of early life exposure to various allergens may decrease the incidence of childhood asthma. In the management of moderate persistent asthma in infants and young children <5 years of age, airway resistance tests (FEV(1) or PEF) are not of significance, but assessment of respiratory rate and skin pulse oximeter measurements of arterial oxygen saturation are helpful. Moreover, recent advances in pharmacogenetics and pharmacogenomics may provide better individualized care for early pharmacological prevention of childhood asthma via selective modulation of airway remodeling.

Effect of ipratropium bromide on EIB in children depends on vagal activity

PURPOSE

Ipratropium bromide (IB) has been used to prevent exercise-induced bronchoconstriction (EIB), but its effect varies among individuals. We hypothesized that such variability may reflect individual differences in vagal activity (VA), and therefore determined whether a correlation exists between VA and the effect of IB on EIB in 13.0 (+/-0.8)-yr-old children with asthma and documented EIB.

METHODS

Subjects served as their own control and were tested on three occasions in an ambient temperature of 5 degrees C. Visit I included no treatment. In visits II and III (counterbalanced sequence) subjects inhaled either 500 microg IB or 0.9% NaCl as a placebo, 45 min before exercise provocation. Investigators and the subjects were blinded to the inhaled substance. VA was assessed by a 4-s exercise test (3). The ratio of resting ECG R-R-interval at full inspiration to the lowest R-R interval during 4-s cycling was taken as an index of VA. Eight-minute cycling at constant work rate (HR=173+/-4 bpm) at 5 degrees C was used to provoke EIB. A two-factor (treatment x time) repeated-measures ANOVA was used.

RESULTS

The exercise-induced drop in FEV1 was similar in the three sessions. However, because the IB caused a 15.7+/-4.1 increase in FEV1 preexercise, the postexercise values after a placebo or no treatment were consistently lower than after IB. The beneficial response to IB, compared with no treatment and with placebo, was positively correlated to VA (for FEV1: r=0.91, P=0.002; and r=0.90, P=0.002, respectively).

CONCLUSION

We suggest that the therapeutic effect of IB on exercise-induced asthma may be related to vagal activity.

Anticholinergic therapy for chronic asthma in children over two years of age

BACKGROUND

In the intrinsic system of controlling airway calibre, the cholinergic (muscarinic) sympathetic nervous system has an important role. Anticholinergic, anti muscarinic bronchodilators such as ipratropium bromide are frequently used in the management of childhood airway disease. In asthma, ipratropium is a less potent bronchodilator than beta-2 adrenergic agents but it is known to be a useful adjunct to other therapies, particularly in status asthmaticus. What remains unclear is the role of anticholinergic drugs in the maintenance treatment of chronic asthma.

OBJECTIVES

To determine the effectiveness of anticholinergic drugs in chronic asthma in children over the age of 2 years.

SEARCH STRATEGY

The Cochrane Airways Group trials register and reference lists of articles were searched in January 2002.

SELECTION CRITERIA

Randomised controlled trials in which anticholinergic drugs were given for chronic asthma in children over 2 years of age were included. Studies including comparison of: anticholinergics with placebo, and anticholinergics with any other drug were included.

DATA COLLECTION AND ANALYSIS

Eligibility for inclusion and quality of trials were assessed independently by two reviewers.

MAIN RESULTS

Eight studies met the inclusion criteria.Three papers compared the effects of anticholinergic drugs with placebo, and a meta-analysis of these results demonstrated no statistically significant benefit of the use of anticholinergic drugs over placebo in any of the outcome measures used. The results of one of these trials could not be included in the meta-analysis but the authors did report significantly lower symptom scores with inhaled anticholinergics compared with placebo. However, there was no significant difference between ipratropium bromide and placebo in the percentage of symptom-free nights or days. Two trials studied the effects of anticholinergics on bronchial hyper responsiveness to histamine, by measuring the provocation dose of histamine needed to cause a fall of 20 % in FEV1 (PD 20). One study (comparing anticholinergics with placebo) reported a statistically significant increase in PD 20 but this was not found in another study (comparing anticholinergics with a beta-2 agonist). Both trials also examined the effect of anticholinergic drugs on diurnal variation in peak expiratory flow rate (PEFR) and reported no significant effect. Two studies compared the addition of an anticholinergic drug to a beta-2 agonist with the beta-2 agonist alone. Both trials failed to show any significant benefit from the long term use of combined anticholinergics with beta-2 agonists compared with beta-2 agonists alone. One trial compared the effects of oral and inhaled anticholinergic drugs with placebo. No statistically significant differences were found in any of the outcome measures except for a higher FEV1 / VC ratio and RV / TLC ratio with oral anticholinergic therapy when compared with placebo.

REVIEWER'S CONCLUSIONS

The present review summarises the best evidence available to date. Although there were some small beneficial findings in favour of anticholinergic therapy, there is insufficient data to support the use of anticholinergic drugs in the maintenance treatment of chronic asthma in children.

Impact of a bronchiolitis guideline: a multisite demonstration project

STUDY OBJECTIVES

The purpose of this study was to determine the impact of a multisite implementation of an evidence-based clinical practice guideline for bronchiolitis.

DESIGN

Before and after study.

SETTING

Eleven Child Health Accountability Initiative (CHAI) study hospitals.

PATIENTS

Children < 12 months of age with a first-time episode of bronchiolitis.

INTERVENTION

The guideline was implemented in December 1998. Complete preimplementation and postimplementation administrative data on hospital admissions, resource utilization, and length of stay were available from seven study hospitals. At five sites, chart reviews were conducted for data on the number and type of bronchodilators used.

MEASUREMENTS AND RESULTS

Complete administrative data were available for 846 historical control subjects and 792 study patients. Length of stay decreased significantly. While the proportion of eligible patients who received any bronchodilator did not change (84%), the proportion of patients who received albuterol decreased from 80 to 75% after guideline implementation (p < 0.03). For patients who received bronchodilators, the mean (+/- SD) number of doses decreased from 13.6 +/- 14.0 to 7.3 +/- 9.1 doses (p < 0.0001). For patients who received albuterol, the mean number of doses decreased from 12.8 +/- 11.8 to 6.4 +/- 7.8 doses (p < 0.0001). Other resource use decreased modestly. Hospital readmission rates within 7 days of discharge were unchanged.

CONCLUSIONS

We successfully extended the implementation of an evidence-based clinical practice guideline from one hospital to seven hospitals. Within just a single bronchiolitis season, some significant changes in practice were seen. The multisite CHAI collaborative appears to be a promising laboratory for large-scale quality improvement initiatives.

Lower arrythmogenic risk of low dose albuterol plus ipratropium

OBJECTIVE

Wheezy infants are in need of urgent bronchodilatation owing to their intermittent bronchoconstriction. beta 2 agonists are frequently used in emergencies and have previously shown to increase the QT dispersion (QTd), which may be associate with high risk of cardiac arrhythmia, in asthmatics. However, effect of low dose beta 2 agonist therapy in combination with the anticholinergic agents on QTd in wheezy infants is not known. This study aimed to assess the effect of standard dose of nebulized albuterol (NAB) and low doses of NAB combined with ipratropium-bromide (NIB) on QTd in wheezy infants.

METHODS

Twenty-nine children, under 2 years old, with the diagnosis of wheezy infant with acute exacerbation were enrolled in the study. Thirteen were treated by standard dose of NA therapy (0.15 mg/kg) and low doses of NAB (0.075 mg/kg) plus NIB (250 micrograms/dose) therapy was given to the remaining subjects. Respiratory distress score, O2 saturation and side effects were studied and QTd were measured from the standard electrocardiograms at baseline and after treatment. Significant improvement was achieved in clinical score and oxygenation of both groups.

RESULT

The evaluation of the corrected QTd (QTcd) showed that there was no significant difference between pretreatment values of both groups (p > 0.05). However, while there was no statistically significant difference in the pre and post-treatment values of QTcd of infants treated with combination therapy, QTcd was found to be significantly increased in NAB group after treatment (p < 0.05).

CONCLUSION

Our results suggest that, while clinical improvement is same, the increase of the QT dispersion is more prominent with the use of standard dose of NAB compared to low dose NAB plus NIB therapy. So, low dose of beta 2 agonist in combination with anticholinergic agents may much safer than the use of standard dose of beta 2 agonists alone in regard to preventing the possibility of arrythmogenic effects in wheezy infants with acute exacerbation.

Treatment and Prevention of RSV Bronchiolitis

Respiratory syncytial virus is a leading cause of bronchiolitis and pneumonia in children worldwide, resulting in significant morbidity and mortality in high-risk individuals. The pediatric populations at high risk for severe RSV infections include patients with cardiac disease, lung disease, immunosuppression, premature birth or healthy infants less than six months of age. Supportive care is the primary treatment of RSV lower respiratory tract infections. Other treatment regimens include the use of bronchodilators and anti-inflammatory agents; however, the use of these agents is controversial due to lack of evidence of efficacy in all studies. Ribavirin, an antiviral agent, has been administered for the treatment of RSV lower respiratory tract infections, but its efficacy has been questioned due to flawed study designs. RSV-IVIG and palivizumab are approved for the prevention of RSV infection in selected children at high risk for serious disease. These agents are equally efficacious and expensive; however, the cost-effectiveness of prophylaxis is unclear. Currently, no vaccines for RSV are available for general use, but research in the area continues. Until a safe, effective and relatively inexpensive method for prophylaxis is available, RSV infections will continue to cause significant morbidity and mortality in children.

Autonomic regulation after exercise evidenced by spectral analysis of heart rate variability in asthmatic children

BACKGROUND

Bronchial asthma is associated with abnormal autonomic nervous function in childhood. Exercise is one of the most common precipitating factors of acute asthmatic crises although the exact mechanism of autonomic regulation in asthmatic children after exercise is unclear.

OBJECTIVE

The aim of this study was to investigate the features of autonomic regulation after exercise in asthmatic and control children.

METHODS

Pulmonary function tests and heart rate variability spectral analysis were performed in 15 asthmatic children and 7 control children (age 6 to 15 years) during and after an exercise challenge.

RESULTS

The maximum % fall of forced expiratory volume in 1 second (FEV1) was significantly greater (P < .01) in asthmatic subjects (9.1 +/- 5.1%) than in normal control subjects (1.0 +/- 2.5%). The high frequency band (HF) amplitude, an index of cardiac vagal tone, 5 minutes after exercise was significantly higher (P < .05) in the asthmatic subjects (14.4 +/- 7.9 msec) than in control subjects (5.9 +/- 2.6 msec). Furthermore, the difference in the HF amplitude between the control group and the exercise-induced asthma group was significant both 5 minutes (P < .01) and 10 minutes (P < .05) after challenge. There was a significant correlation (P = .565, P = .0165) between HF amplitude 5 minutes after exercise and the magnitude of the decrease in FEV1. On the other hand, no significant difference was observed in the low frequency band amplitude between the controls and the asthmatic subjects. The ratio of low frequency to high frequency power, which is suggested to correlate with cardiac sympathetic activity, did not differ between the two groups.

CONCLUSION

These findings suggest that autonomic nervous activities, particularly vagal response after exercise, in asthmatic children is different from that in control children.

Inhaled budesonide for the treatment of acute wheezing and dyspnea in children up to 24 months old receiving intravenous hydrocortisone

BACKGROUND

Inhaled corticosteroids are highly effective in the treatment of asthma at all ages, and their use in younger children is increasing. There are no data currently available on the treatment of infants with acute wheeze and dyspnea with nebulized budesonide.

OBJECTIVE

Our purpose was to assess the clinical effect of nebulized budesonide in infants with acute wheeze and dyspnea.

METHODS

A prospective study was performed comparing the addition of nebulized budesonide 0.25 mg every 6 hours (group A, n = 32) and nebulized ipratropium bromide 0.1 mg every 6 hours (group B, n = 39) with the normal treatment regimen with intravenous fluid, hydrocortisone, and nebulized fenoterol. A clinical score was made at admission and every 12 hours. The score included wheezing and costal retraction (0-6) and respiratory rate (counts per minute).

RESULTS

Seventy-one infants aged 3 to 24 months were studied (42 boys). A statistically significant reduction was seen in clinical score and respiratory rate in both groups 12 hours after admission. The children who received budesonide improved significantly faster than the children who received ipratropium bromide, and the hospitalization period was significantly lower in the budesonide group (66.4 hours) compared with the ipratropium bromide group (93 hours) (P <.01). Three patients from the budesonide group and 2 from the ipratropium bromide group were readmitted within the first 4 weeks.

CONCLUSION

Treatment of infants with acute wheeze with nebulized budesonide is associated with faster clinical improvement and reduction in hospital stay period.

Evaluation of an evidence-based guideline for bronchiolitis

OBJECTIVE

To describe the effect of implementing an evidence-based clinical practice guideline for the inpatient care of infants with bronchiolitis at the Children's Hospital Medical Center in Cincinnati, Ohio.

METHODOLOGY

A multidisciplinary team generated the guideline for infants < or = 1 year old who were admitted to the hospital with a first-time episode of typical bronchiolitis. The guideline was implemented January 15, 1997, and data on all patients admitted with bronchiolitis from that date through March 27, 1997, were compared with data on similar patients admitted in the same periods in the years 1993 through 1996. Data were extracted from hospital charts and clinical and financial databases. They included LOS and use and costs of resources ancillary to bed occupancy.

RESULTS

After implementation of the guideline, admissions decreased 29% and mean LOS decreased 17%. Nasopharyngeal washings for respiratory syncytial virus were obtained in 52% fewer patients. Twenty percent fewer chest radiographs were ordered. There were significant reductions in the use of all respiratory therapies, with a 30% decrease in the use of at least 1 beta-agonist inhalation therapy. In addition, 51% fewer repeated inhalations were administered. Mean costs for all resources ancillary to bed occupancy decreased 37%. Mean costs for respiratory care services decreased 77%.

CONCLUSIONS

An evidence-based clinical practice guideline for managing bronchiolitis was highly successful in modifying care during its first year of implementation.guideline, bronchiolitis, evidence-based medicine, pediatrics, outcome research.

Effect of continuously nebulized ipratropium bromide plus albuterol on emergency department length of stay and hospital admission rates in patients with acute bronchospasm. A randomized, controlled trial

OBJECTIVE

To compare the outcome of patients with acute bronchospasm treated with continuously nebulized albuterol plus ipratropium bromide vs albuterol alone.

SETTING

The Emergency Department (ED) at the University of California San Francisco Medical Center.

PARTICIPANTS

Patients > or = 18 years old presenting to the ED with acute bronchospasm and a peak expiratory flow rate (PEFR) of < 70% predicted.

INTERVENTIONS

This was a prospective, randomized, double-blind, placebo-controlled trial. Subjects were treated with either a combination of albuterol (10 mg/h) plus ipratropium bromide (1.0 mg/h) or albuterol alone via continuous nebulization for a maximum of 3 h. Vital signs, Borg dyspnea score, and PEFR were recorded hourly. Primary outcome measures were improvement in PEFR, hospital admission rates, and length of stay in the ED.

MEASUREMENTS AND RESULTS

Data was analyzed for 67 subjects. The mean age (-/+ SD) was 47.5+/-18.8, and mean initial PEFR was 44.8+/-12.5% of predicted. The median length of stay for all subjects was 225 min, and 31% of all subjects were admitted. Patients given combination therapy averaged 6.3% greater improvement in PEFR compared with control subjects (95% confidence interval [CI], -15% to 27%. The odds ratio for admission with combination therapy was 0.88 (95% CI, 0.28 to 2.8). The median length of stay in the ED was 35 min shorter for those receiving combination treatment (210 vs 245 min; p = 0.03). However, when adjusted for initial PEFR, there was no statistically significant difference (p = 0.26).

CONCLUSION

Although the direction of all three outcome measures favored combination therapy, there was no statistically significant difference between ED patients with acute bronchospasm receiving continuous albuterol plus ipratropium bromide and those receiving albuterol alone.

Effect of oral and inhaled salbutamol in infants with bronchiolitis

The response of bronchiolitis to bronchodilator drugs is controversial. The present study was designed to evaluate the efficacy of oral or metered dose inhaler (MDI) salbutamol using a coffee cup as a spacer device in bronchiolitis. In the trial, 31 hospitalized patients between 6 and 24 months of age, who exhibited the first episode of acute bronchiolitis without any other predisposing illness such as cystic fibrosis, congenital heart disease etc., were randomly assigned to receive oral salbutamol (n = 11, 0.1 mg/kg per dose, four times a day), or MDI salbutamol (n = 12, 200 micrograms per dose, every 3 h) or formed the control group without any bronchodilator therapy (n = 8). All of the patients were given supplemental oxygen as needed and adequate hydration was maintained. The patients were evaluated with clinical symptom scores. There were no differences in the beneficial or side effects of salbutamol, or the number of days in hospital between the treatment groups and the control group. It was concluded that there is no beneficial effect in using bronchodilators in infants with bronchiolitis. Supplemental oxygen and maintenance of normal hydration may be adequate.