Spacing devices and metered-dose inhalers in childhood asthma

The Effect of Cromolyn Sodium and Nedocromil Sodium Administered by A pressurized Aerosol with A spacer Device on Exercise-Induced Asthma in Children

To compare the effectiveness of cromolyn sodium (CS) (10 mg) and nedocromil sodium (NS) (4 mg) administered by a metered dose inhaler (MDI) with a spacer device in preventing exercise-induced asthma (EIA), eight asthmatic children with EIA were studied in a randomized double-blind, cross-over, placebo-controlled study, CS and NS provided significant, comparable protection from EIA and both were better than placebo. We conclude that CS and NS administered by a pressurized aerosol with a spacer device provide equal protection against EIA in children.

Emitted doses of salbutamol pressurized metered-dose inhaler from five different plastic spacer devices

In a recent clinical study we have demonstrated that the bronchodilator effect of 200 microg salbutamol (Ventoline) was spacer device-dependent in 100 tested asthmatic children, with the Babyhaler providing greater efficacy for improving peak expiratory flow rate compared to Aeroscopic, Nebuhaler, Aerochamber and Volumatic. The aim of this present study was to correlate our clinical results to in vitro determinations of the emitted dose (ED) of Ventoline administered via these five different plastic spacer devices. ED was determined from the mean of single doses collected in unit dose sampling tubes using a constant suction flow of 28.3 L/min. Three pressurized metered-dose inhalers and three sets of spacer devices were used to obtain a total of 30 measurements per group. Inter-group results were compared by RM-ANOVA or Student-Newman-Keuls method when indicated. Babyhaler delivered significantly (P < 0.05) more salbutamol than Nebuhaler, Aerochamber and Aeroscopic (mean +/- standard deviation: 63.6 +/- 2.9 microg/100 microg actuation for Babyhaler vs. 59.4 +/- 8.6 for Nebuhaler, 50.8 +/- 5.0 for Aerochamber and 47.5 + 2.5 for Aeroscopic). The ED from Volumatic (61.5 +/- 7.9 microg/100 microg actuation) was similar to that from the Babyhaler. The variability in the ED was greatest with the large volume spacers. Despite a greater ED from the Babyhaler, in vitro results do not fully explain the in vivo results. However, the previously described clinical improvement seen with the Babyhaler may be due to the quantitatively different aerosol production in a more 'useful' size range, as well as the different breathing patterns of the children tested. The results of this present study question the relevance of mouthpiece filter collection studies using a constant sampling in predicting clinical or physiological outcomes.

Effect of detergent-coated versus non-coated spacers on bronchodilator response in children with asthma

OBJECTIVE

Previous studies have demonstrated that coating spacers with ionic detergents minimizes the static charge and thereby improves in vivo drug deposition. The present study aims to examine the effect of coated spacers versus non-coated spacers in the clinical situation.

METHODS

A randomized, double-blind study in children with asthma and a ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) of < or =72% predicted was carried out. Spirometry was performed at baseline and at 10 min and 20 min after inhalation of two puffs of salbutamol (100 microg/puff) through either a detergent-coated or a non-coated spacer.

RESULTS

Fifty children were studied (mean age 11.6 years, range 7-18 years): 26 in the group using coated spacers (CG); and 24 in the group using non-coated spacers (NCG). The mean percentage change in FEV1 from baseline 10 min after inhalation was 18.8% (range 5-50%) in the CG versus 18.5% (range 3-35%) in the NCG. At 20 min after inhalation, the per cent increase in FEV1 was 19.8% (range 0-50%) in the CG versus 19.5% (range 9-35%) in the NCG. There was no significant difference between groups in the percentage change in FEV1 after 10 min (P = 0.91), or after 20 min (P = 0.93).

CONCLUSIONS

There was no improvement in bronchodilatation from detergent-coated spacers in the present study, possibly because a maximal bronchodilator response was achieved with the lower output.

Using a matrix as an educational approach to asthma

Health care providers agree that asthma care must be individualized to fit the need of the child and family. A written plan in the form of a matrix enables the health care provider to give families a step-by-step individualized plan of care for asthma. This article discusses the use of a long-term treatment plan in matrix form as an educational tool for health care providers and for families. The written long-term plan can be used to guide treatment for any level of asthma severity. Following a review of asthma pathogenesis and diagnosis, categories of medications are presented, along with their role in a long-term treatment plan. The National Heart, Lung, and Blood Institute guidelines are used as a basis for the recommendations in the long-term treatment plan.

Metal versus plastic spacers: an in vitro and in vivo comparison

This study compared the metal Nebuchamber with the polycarbonate Volumatic spacer in vivo as well as in vitro. Seventeen asthmatic patients were evaluated in a crossover placebo-controlled double-blind study. Bronchodilation, heart rate and serum potassium levels were measured at baseline and 15 min after administration of salbutamol. Cumulative dose-response curves (200, 400, 800 and 1600 microg) were constructed. The Andersen Cascade Impactor was used to compare the aerodynamic particle size distribution. The FEV(1) measurements showed highly significant differences between placebo and the two active preparations (P<0.001), but not between the two active preparations (P=0.433). The serum potassium levels also showed highly significant differences between placebo and the two active preparations (P=0.009), but not between the two active preparations (P=0.532). Only 1600 microg salbutamol dose raised the heart rate significantly, but the difference between the two active preparations was not significant. The in vitro deposition study revealed no significant differences in the delivered dose or in the fine particle dose (P>0.05). In conclusion, there are no significant differences between the Volumatic and Nebuchamber either in vivo or in vitro.

Exercise-induced asthma in children

Exercise-induced asthma (EIA) is a relatively common problem in children, but may not be recognized because children either do not report their symptoms, or avoid activities that cause it. Clarifying the diagnosis of EIA, in particular separating EIA from other causes of exertional dyspnea, is essential. Treating EIA in children is challenging because of the nature of their physical activities, which are often not planned, and may be prolonged. Keeping children active is an important goal to ensure healthy physical and social development. Many children with EIA are well managed with an inhaled short-acting beta(2)-adrenoceptor agonist before exercise or if symptoms develop. The approach to more troublesome EIA depends on whether the child has persistent asthma and requires better prevention, or the EIA is an isolated clinical problem. The options for treatment also depend on the timing, frequency, and duration of activity that induces EIA. Options include the addition of a cromone, a leukotriene modifier, an inhaled corticosteroid, or switching to use a long-acting beta(2)-adrenoceptor agonist. The use of warm-up exercises has been shown to be helpful by using the refractory period but is not practical for most children with EIA. A final consideration for successful management of EIA in children is that the delivery of medication needs to be age-appropriate.

Ex-vivo product performance of Diskus and Turbuhaler inhalers using inhalation profiles from patients with severe chronic obstructive pulmonary disease

Dosing performance of dry powder inhalers is dependent on patient's inspiratory effort. This study compares the inhalation profiles generated by patients with severe obstructive lung disease using Diskus and Turbuhaler inhalers. The patient profiles are subsequently used to determine the dosing performance of fluticasone propionate Diskus and budesonide Turbuhaler inhalers. Inhalation profiles were recorded in COPD patients (FEV1 < or = 30% predicted) as they inhaled with maximal effort through the inhalers. The profiles were used in an inhalation simulator to assess the dosing performance by measuring the total emitted dose and the fine particle mass for each inhaler type. Peak inspiratory flow was significantly higher through the Diskus (mean 82.31 min(-1)) compared with Turbuhaler (mean 53.51 min(-1), difference = 28.8 l min(-1); P < 0.0001). In addition, in direct comparison of the two devices. the Diskus was shown to deliver a more consistent dose irrespective of flow than the Turbuhaler in this patient population. These findings may be of importance in optimising selection of devices for patients with severe airway obstruction.

Effect of electrostatic charge, flow, delay and multiple actuations on the in vitro delivery of salbutamol from different small volume spacers for infants

BACKGROUND

A study was undertaken to determine the influences of electrostatic charge, flow, delay, and multiple actuations on the in vitro delivery of salbutamol generated by a pressurised metered dose inhaler (pMDI) from small volume spacers used in infants.

METHODS

Ten actuations from a salbutamol pMDI were drawn at different flow rates after either single or multiple actuations, with or without delay, through either static or reduced static spacers. An ionic detergent was used to reduce the charge of plastic spacers (Babyhaler, Babyspacer, Aerochamber, Nebuhaler). Electrostatic charge was measured using an electrometer. A multistage liquid impinger was used to determine the particle size distribution of the output of the pMDI through the spacers.

RESULTS

Electrostatic charge on the surface of plastic spacers had the greatest influence on delivery, causing a decrease in drug delivery. Reducing charge by coating the surface with ionic detergent resulted in an increase of 46.5-71.1% (p < 0.001) in small (< 6.8 microns) particle delivery from small volume plastic spacers. Lower flow, delay, and multiple actuations resulted in decreased delivery from static spacers. Lower flow resulted in a decrease of 15% in small (< 9.6 microns) particle delivery. Delay and multiple actuations resulted in a decrease of 40.7% and 76.0%, respectively, in small (< 6.8 microns) particle delivery. The influences of lower flow, delay, and multiple actuations were greatly reduced or even eliminated by reducing charge. However, multiple actuations still resulted in a significant decreased delivery (p < 0.05). The reduced static Nebuhaler had a higher delivery than all small volume spacers.

CONCLUSIONS

Electrostatic charge has a major influence on the delivery of salbutamol from small volume spacers. Using a metal spacer or ionic detergent coating of plastic spacers resulted in no or reduced charge and hence in improved delivery. Lower flow, delay, and multiple actuations played a major part only in static spacers.

Development of a scale to measure children's metered-dose inhaler and spacer technique

BACKGROUND

A measure of metered dose inhaler (MDI) and spacer technique would help health care providers to estimate the degree to which technique may confound clinical efficacy of inhaled medications.

OBJECTIVE

Our purpose was to extend earlier efforts to develop a rating scale to assess the accuracy of children's technique in using an MDI with three of the newer spacer devices.

METHODS

Subjects were children, 7 to 17 years old, with moderate to severe asthma attending a follow-up appointment in an outpatient specialty clinic for asthma. Nurse practitioners and/or physicians completed a rating scale (MDI Check-list) for 50 children using an Optihaler spacer, 29 using Azmacort, and 21 using InspirEase.

RESULTS

Depending on the spacer used, 14% to 26% of the children failed to demonstrate the critical skills for delivering medicine to the conducting airways, with the InspirEase group showing the best results. Items vary in difficulty (percent correct). The scale has excellent internal consistency reliability for Optihaler.

CONCLUSIONS

The scale can be used (1) by health care providers to instruct patients or colleagues, (2) by parents to monitor and correct their children's MDI/spacer technique, and (3) by researchers to estimate drug delivery in studies of clinical outcome or adherence.

Inhalational drug delivery from seven different spacer devices

BACKGROUND

A study was performed to determine in vitro the difference in drug output of seven currently available spacer devices when used with different inhaled medications.

METHODS

A glass multistage liquid impinger (MSLI) was used to determine the amount of disodium cromoglycate (DSCG, 5 mg), salbutamol (100 micrograms), or budesonide (200 micrograms) obtained in various particle size ranges from metered dose inhalers (MDIs) actuated directly into the MSLI or via one of seven different spacer devices; the Fisonair, Nebuhaler, Volumatic, Inspirease, Aerochamber, Aerosol Cloud Enhancer, and Dynahaler.

RESULTS

In particles smaller than 5 microns in diameter the dose of DSCG recovered from the Fisonair and Nebuhaler was 118% and 124%, respectively, of that recovered using the MDI alone. The dose recovered from the smaller volume spacers was 90% (Inspirease), 36% (Aerochamber), 33% (Aerosol Cloud Enhancer), and 21% (Dynahaler) of that from the MDI alone. The Volumatic increased the amount of salbutamol in particles smaller than 5 microns to 117% of that from the MDI, and the Inspirease and Aerochamber spacers decreased it by nearly 50%. The amount of budesonide in small particles recovered after use of the Nebuhaler, Inspirease, and the Aerochamber was 92%, 101%, and 78%, respectively, of that from the MDI alone.

CONCLUSIONS

Under the test conditions used, large volume spacers such as the Fisonair, Nebuhaler, and Volumatic delivered significantly more DSCG and salbutamol than the smaller spacers tested. The differences between spacers were less for budesonide than the other medications studied. This study shows that there are significant differences in the amount of drug available for inhalation when different spacers are used as inhalational aids with different drugs. Spacer devices need to be fully evaluated for each drug prescribed for them.

Physician-targeted program on inhaled therapy for childhood asthma

BACKGROUND

Inhaled medications are the mainstay of asthma therapy, but significant deficiencies exist in the knowledge and skills of physicians regarding use of metered-dose inhalers (MDI) and spacer devices.

OBJECTIVE

We developed, implemented, and evaluated the effects of a physician-targeted educational program on inhaled therapy in a group of pediatric residents in our institution.

METHODS

Patient-directed instruction sheets on aerosol therapy were developed on the basis of literature review and expert guidelines. These served to establish a consistent foundation for the educational curriculum. The program was delivered through one-on-two teaching sessions (45 minutes). Residents were provided with a summary of theoretical and practical information and with devices for practice (a placebo MDI, InspirEase and AeroChamber holding chambers, and the AeroChamber device with mask). Each session included review of an educational monograph, demonstration of proper technique, and practice with the different devices. The program was evaluated by a randomized-control design. Assessment of practical skills included number of correct steps for the use of MDI (maximum score, 7), InspirEase (maximum, 7) and AeroChamber (maximum, 6). Theoretical knowledge was assessed with 25 multiple-choice questions.

RESULTS

Pretest scores in the experimental group (n = 24) were 3.7 of 7, 1.9 of 7, and 0.3 of 6 steps correct for MDI, InspirEase, and AeroChamber devices, respectively, and 13 of 25 for the theoretical knowledge assessment. The control group (n = 26) had similar pretest scores. After the program the experimental group significantly improved in all parameters: 6.3 of 7, 5.9 of 7, and 4.5 of 6 steps correct for MDI, InspirEase, and AeroChamber devices, respectively, and 18 of 25 questions correct (p < 0.01 for all parameters).

CONCLUSIONS

Implementation of a simple educational program among pediatric residents can significantly increase their skills in the use of inhalational therapy.

What do pediatricians in training know about the correct use of inhalers and spacer devices?

Most patients with asthma in the United States are cared for by nonspecialist physicians. Because inhaled medications are the mainstay of asthma therapy and their successful use requires both practical skills and theoretic knowledge, we wondered how much nonspecialist physicians know about the use of metered-dose inhalers and spacer devices. Fifty pediatricians in training were interviewed individually. Practical knowledge was assessed by asking each to demonstrate correct use of a placebo inhaler and a spacer device (Inspirease [Key Pharmaceuticals, Inc., Miami, Fla.] and Aerochamber with mask [Monaghan Medical Corp., Plattsburgh, N.Y.]). Of the seven recommended steps for use of metered-dose inhalers, the residents demonstrated an average of 3.8 steps correctly. The most common errors included not shaking the metered-dose inhaler before use (18% of residents correct) and insufficient breath holding (28% correct). In testing spacer use, the most common errors included not shaking the canister (16% correct) and incorrect number of activations and inhalations (12% correct). Many residents were not familiar with correct assembly of the spacer (48% correct). Theoretic knowledge of metered-dose inhaler and spacer use was evaluated by a written questionnaire. The most common deficiencies in theoretic knowledge related to the purpose of slow inspiration and breath holding. Most of the participants had been treating children with asthma and had prescribed metered-dose inhalers (45 of 50, 90%) and spacer devices (76%) in the past.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of albuterol administered by nebulizer versus spacer device in children with acute asthma

The aim of this study was to compare the response to inhaled albuterol after administration by nebulizer with the response after administration by a metered-dose inhaler and spacer device (MDI-spacer) to children with acute asthma. In a double-blind fashion, 33 children (6 to 14 years of age) with forced expiratory volume in 1 second (FEV1) between 20% and 70% of predicted values, and who were seen in the emergency department with acute asthma, were studied. They were treated with aerosolized albuterol or placebo by MDI-spacer, followed immediately by albuterol or placebo administered by nebulizer with oxygen. The dose ratio for albuterol by MDI-spacer versus nebulizer was 1:5. Outcome measures included a clinical score, respiratory rate, arterial oxygen saturation, and FEV1, measured before and 10, 20, and 40 minutes after treatment. With the exception of heart rate (which increased in the nebulizer group and decreased in the MDI-spacer group (p < 0.05), no difference in the rate of improvement of clinical score, respiratory rate, arterial oxygen saturation, or FEV1 was noted during the 40-minute study period between children who received albuterol by nebulizer and those who received it by MDI-spacer. We conclude that spacers and nebulizers are equally effective means of delivering beta 2-agonists to children with acute asthma.

Drug delivery from holding chambers with attached facemask

There is much interest in the use of holding chambers with an attached facemask to deliver aerosols from metered dose inhalers to infants. In order to study the influence of various design factors on the dose inhaled at different tidal volumes, a model was constructed in which a Starling ventilator was used to generate an inspiratory/expiratory cycle across a filter. Sodium cromoglycate was administered via a Nebuhaler and mask, Aerochamber and mask, and a coffee cup using tidal volumes of 25, 50, and 150 ml and the dose deposited upon the filter after six breaths was assayed using an ultraviolet spectrophotometric method. At the lowest tidal volume the high aerosol concentration in the smaller chamber enhanced drug delivery while at the highest tidal volume delivery was greatest from the larger chamber reflecting the larger dose available. Multiple breaths ensured that the dose inhaled per kilogram from each chamber was relatively large and also permitted significant drug delivery despite the introduction of a relatively large dead space between valve and filter. The dose delivered was increased by increasing the dose introduced into the chamber though not proportionately. These devices appear likely to deliver significant quantities of aerosol to infants, though drug delivery may be enhanced by the use of an appropriate valve.

Ipratropium bromide for symptomatic preterm infants

Twelve preterm infants, median gestational age 31.5 weeks, were entered into a randomised, placebo-controlled trial of bronchodilator therapy. Their postnatal age was a median of 17.5 months and all suffered from recurrent respiratory symptoms. The infants received either inhaled placebo or 40 micrograms of ipratropium bromide (active therapy) three times a day utilising a coffee cup as a spacer device. Each therapy was administered for 2 weeks. The symptom score during the active period was reduced by 59% compared to the placebo period (P less than 0.01) and this was associated with 38% improvement in lung function in the active period compared to a 20% change in functional residual capacity over the placebo period (P less than 0.01). We conclude inhaled ipratropium bromide appears to be an effective treatment for symptomatic infants at follow up.

Comparative efficacy of terbutaline administered by Nebuhaler and by nebulizer in young children with acute asthma

We compared the use of terbutaline sulphate that was delivered by a nebulizer with its delivery by a Nebuhaler at two dose levels in 27 children (nine children per group) of between three and six years of age with acute asthma. No significant difference was found in the mean baseline clinical score among the three groups, and a significant decline occurred in the mean clinical scores in all groups by 15 minutes which was maintained to 60 minutes after the dose was administered. The decline that was achieved with delivery of the drug by way of a Nebuhaler (at either dose level) was not significantly different from that with a nebulizer, although cooperation with Nebuhaler usage was not universal in the age-group.

Sodium cromoglycate in asthma: correlation between response and serum concentrations

The clinical response to sodium cromoglycate treatment was compared with its concentration in serum. Twenty five children with asthma entered a 10 week trial of two baseline weeks followed by eight weeks of treatment by the inhalation of 20 mg of sodium cromoglycate spincaps four times a day. Individual clinical response was determined by the differences between baseline and treatment periods of: (a) percentage of symptomless days (delta score 0); (b) diary derived daily score for four symptoms (delta DS); and (c) peak expiratory flow rate (delta PEFR). At the end of the treatment period, patients inhaled a 20 mg spincap of sodium cromoglycate and the technique of inhalation was graded. Concentrations of sodium cromoglycate in serum were measured by radioimmunoassay in samples withdrawn 5 to 120 minutes after inhalation. Delta Score 0, delta DS, and delta PEFR correlated significantly with the area under the concentration time curve. Both the area under the sodium cromoglycate concentration time curve and clinical response correlated significantly with inhalation technique score. We suggest that response of children with asthma to inhalation treatment with sodium cromoglycate is correlated to its serum concentrations.

An inexpensive spacer for use with metered-dose bronchodilators in young asthmatic children

A 1-liter soft drink plastic bottle was modified as a spacer for use with a metered-dose bronchodilator. Its efficacy was tested on 22 children aged 3.9-7.5 years who had acute asthma. They were randomly selected to receive aerosolized salbutamol or placebo via the plastic bottle. Children who received the salbutamol showed significantly greater degree of bronchodilation than those who received the placebo. No significant adverse effects were observed. Cylindrical plastic bottles of 1-liter capacity may thus be used as a convenient and cheap spacer to effectively deliver metered-dose bronchodilators to children during acute asthma.

A trial of metaproterenol by metered-dose inhaler and two spacers in preschool asthmatics

Because most young children have difficulty in coordination for correct use of metered-dose inhalers (MDI), a trial of two spacer devices attached to MDIs was performed. In 13 children with asthma, aged 2-5 years old, a collapsible bag (Inspir-Ease) and a tube spacer (Aerochamber) were tested in a double-blind crossover trial with metaproterenol (1,300 micrograms). Respiratory resistance was measured by the forced oscillation method. Thirty minutes after metaproterenol administration there was a significant decrease in resistance with both spacers, while no significant change occurred after placebo administration. There was no difference in degree of bronchodilation between the two spacers. It is concluded that metaproterenol can be safely and effectively administered to preschool asthmatics by an MDI with spacer devices.

Bronchodilator effect of fenoterol and ipratropium bromide in infants with acute wheezing: use of MDI with a spacer device

Twenty-eight infants admitted to Exequiel González Cortes Children's Hospital because of acute wheezing (AW) were randomly assigned to three study groups. Fenoterol (FNT), ipratropium bromide (IB), and placebo were administered respectively to children in the different groups by means of metered dose inhalers (MDI) with spacers, using doses of 3 puffs every hour, for 4 hours. The degree of bronchial obstruction was assessed clinically and scored with the single-blind method every hour prior to each treatment. The criterion of a bronchodilator effect was a significant decrease in the degree of bronchial obstruction at subsequent scorings. The scores of the three groups were compared using the Student's t test for matched samples. The same test was also applied to the independent samples for determining the superiority of one treatment, FNT or IB, over the other. The results indicated a significant decrease in the scores of the groups receiving FNT and IB (P less than 0.05); this did not occur in the group in which placebo was used. FNT produced a more rapid and sustained effect than IB (P less than 0.05). Significant bronchodilator effect was obtained in infants with AW when repeated doses of FNT or IB were administered with MDI and spacers. This effect was significantly greater in the group treated with FNT.