Aerosol therapy: the special needs of young children

Assessing of low-tech solutions for aerosol delivery: Comparative performance study of manufactured versus homemade spacers

PURPOSE

This study aims to evaluate the performance of low-cost homemade spacers compared with manufactured valved holding chambers (VHCs) for fluticasone propionate delivery via a pMDI (pressurized Metered Dose Inhaler).

METHODS

The Total Emitted Dose (TED) and particle size distribution were measured for pMDI alone or connected to the different spacers, according to CAN/CSA-Z264.1-02 standard. Two types of low-cost alternative and manufactured spacers were investigated: 500 mL plastic bottle and 553 mL aluminium can; non-antistatic plastic VHCs and aluminium antistatic VHCs.

RESULTS

The TED of homemade plastic bottle vs plastic VHC were similar in the 20-23% range. In contrast, the TED of homemade aluminium can was higher compared to aluminium VHC (83% vs 68%). The Fine Particle Fraction (FPF) was similar for the two plastic-based spacers (in the 12.68-17.60% range), although it was greater for the aluminium can compared to aluminium VHC (51% vs 42%). However, all spacers have limited large particles fraction, mainly deposited in the oropharyngeal tract, potentially decreasing side effects.

CONCLUSION

We demonstrated that low-tech solutions as homemade spacers have at least similar performances to VHC medical devices composed of same material (aluminium or plastic). Thus, low-cost homemade spacers represent alternatives in case of emergency and without VHCs nearby.

Inhalation Devices in 7- to 15-Year-Old Children with Asthma - A Patient Preference Study

Background

Inhalation therapy is the cornerstone of treatment of bronchial asthma. A patient-specific selection of inhalation devices is necessary, as preference for a device plays an important role in terms of error rates in handling and adherence to therapy. However, there is no industry-independent study providing information on children's preferences for common inhaler types. The aim of the present study was to investigate the preference of asthmatic children for inhaler types commonly used in Germany. The effects of age, gender and the type of school visited on device preferences as well as the frequency of patient education and the role of health care providers in the choice for an inhaler were investigated.

Methods

Eighty children were included in this prospective cross-sectional study (age: 10.87 ± 2.62 years). The analysis was based on a questionnaire and validated checklists. All participants tested the use of nine placebo inhalers (Breezhaler, Diskus, Respimat, Spiromax, Turbohaler, Autohaler, metered-dose inhaler, Easyhaler and Novolizer) in a randomized order. For each device, patients were asked to assess handling, rate different device characteristics and name the device they would prefer most or least.

Results

The most favored device was the Novolizer. Moreover, the Spiromax scored highest in numerous categories such as suitability in emergencies and "easiest" device to use. Patient preferences with respect to the addressed inhaler features were not significantly related to age, gender or school type.

Conclusion

The Novolizer and the Spiromax showed higher preference in pediatric patients as compared to other tested devices. Overall, there were significant differences in terms of preference when comparing the tested inhalers in different aspects.

The history, current state and perspectives of aerosol therapy

Nebulization is a very effective method of drug administration. This technique has been popular since ancient times when inhalation of plants rich in tropane alkaloids with spasmolytic and analgesic effects was widely used. Undoubtedly, the invention of anasthesia in the 19th century had an influence on the development of this technique. It resulted in the search for devices that facilitated anasthesia such as pulveriser or hydronium. From the second half of the 21st century, when the first DPI and MDI inhalers were launched, the constant development of aerosol therapy has been noticed. This is due to the fact that nebulization, compared with other means of medicinal substance application (such as oral and intravenous routes of administration), is safer and it exhibits a positive dose/efficacy ratio connected to the reduction of the dose. It enables drugs administration through the lung and possesses very fast onset action. Therefore, various drugs prescribed in respiratory diseases (such as corticosteroids, β-agonists, anticholinergics) are present on the market in a form of an aerosol.

Bronchodilating effects of a new beclometasone dipropionate plus formoterol fumarate formulation via pressurized metered-dose inhaler in asthmatic children: a double-blind, randomized, cross-over clinical study

A new pediatric fixed combination of beclometasone dipropionate (BDP) 50 μg and formoterol fumarate (FF) 6 μg via pressurized metered-dose inhaler (pMDI) (CHF1535, Chiesi, Italy) was investigated. In a double-blind, randomized, placebo-controlled, cross-over study, a single CHF1535 administration using AeroChamber Plus™ spacer device (2 actuations, total dose BDP 100 μg/FF 12 μg) was compared to the same pMDI free combination in 56 asthmatic children aged ≥ 5 and < 12 years. Primary efficacy variable was forced expiratory volume during the first second (FEV₁) area under the curve corrected by time over 12 h following morning dose (AUC_0-12h). Further CHF1535 doses (50 μg/6 μg, 100 μg/12 μg, and 200 μg/24 μg) were also explored. Adverse events, electrocardiogram, and vital signs were monitored for safety. CHF1535 was non-inferior to free combination [adjusted mean difference (95% CI) 0.004 L (- 0.050, 0.041] with lower confidence limit greater than the limit set at 0.1 L. FEV₁ AUC_0-12h of each CHF1535 dose vs placebo were 0.037 L (p = 0.160), 0.119 L (p < 0.001), and 0.094 (p < 0.001) for 50/6, 100/12, and 200/24, respectively. No safety signals were found.Conclusion: CHF1535 was as effective as free combination BDP/FF, with a trend towards a dose-related response. All treatments were safe.Trial registration: ClinicalTrials.gov ID: NCT01584492 What is Known: •Inhaled pressurized metered-dose solutions (pMDI) are the preferred treatment for pediatric asthma. •Combination therapy of inhaled corticosteroids and long-acting β₂- agonists is a well-established approach to control airway inflammation and airway obstruction also in pediatric patients. What is New: •A novel pediatric pMDI fixed combination of beclomethasone dipropionate 50 μg and formoterol fumarate 6 μg (CHF 1535) was non-inferior to the free combination at the same dose in pulmonary function over the 12-h post-dose period in asthmatic children, with trend towards a dose-related response.

A path to successful patient outcomes through aerosol drug delivery to children: a narrative review

Although using aerosolized medications is a mainstay of treatment in children with asthma and other respiratory diseases, there are many issues in terms of device and interface selection, delivery technique and dosing, as well as patient and parental education that have not changed for half a century. Also, due to many aerosol devices and interfaces available on the market and the broad range of patient characteristics and requirements, providing effective aerosol therapy to children becomes a challenge. While aerosol delivery devices are equally effective, if they are age-appropriate and used correctly, the majority of aerosol devices require multiple steps to be used efficiently. Unfortunately, many children with pulmonary diseases have problems with the correct delivery technique and do not gain therapeutic benefits from therapy that result in poor disease management and increased healthcare costs. Therefore, the purpose of this paper is to review the current knowledge on aerosol delivery devices used in children and guide clinicians on the optimum device- and interface-selection, delivery technique, and dosing in this patient population. Strategies on how to deliver aerosolized medications in crying and distressed children and how to educate parents on aerosol therapy and promote patient adherence to prescribed medications are also provided. Future directions of aerosol therapy in children should focus on these issues and implement policies and clinical practices that highlight the potential solutions to these problems.

[Bench-test evaluation of spacer devices for fluticasone delivery to infants]

INTRODUCTION

Use of a spacer device to optimize the delivery of fluticasone to infants with asthma is an important issue and clinicians require guidance around the choice of device. This in vitro study characterizes the particle size and the fluticasone delivery via 9 spacers.

METHODS

We used an in vitro infant nasal cast with two different inspiratory flow rates (50 and 100mL/s). Fluticasone particle size in the aerosol was evaluated by laser diffractometry and tracheal deposition by spectrophotometric assay.

RESULTS

Significant differences in particle size were observed between the 9 spacers (similar D50 but D90 from 5.65±0.65 to 8.80±1.35μm). A 75 % or higher respirable fraction was obtained for only 5 spacers. The 50mL/s flow rate lead to the best drug delivery. At this flow, OptiChamber^® (62±3 %) and Vortex^® (91±8.5 %) had a tracheal deposition over 50 % of the initial dose of fluticasone, although the 7 other spacers exhibited a fluticasone deposition less than 25 %.

DISCUSSION

This study shows a wide variation of drug delivery between the 9 spacers studied. We demonstrate that a low inspiratory flow and a spacer showing antistatic properties facilitate drug delivery.

An instrumented valved holding chamber with facemask to measure application forces and flow in young asthmatic children

BACKGROUND

Pressurized metered dose inhalers (pMDIs), combined with a valved holding chamber (VHC) and facemask, are often used for young asthmatic children. When using a VHC with facemask, a tight seal between the facemask and the patient's face is crucial for efficient pulmonary aerosol delivery. Realistic parameters for in vitro bench testing are not well known. A custom instrumented OptiChamber Diamond VHC, known as the Facemask Datalogger, was developed to measure the real-time application of force and the air flow through the VHC and facemask.

METHODS

Thirty asthmatic children aged 1-4 years from the Kinderhaven outpatient clinic, who were prescribed a pMDI/VHC with facemask for regular use, were included in the study. Using the Facemask Datalogger, the parent applied the facemask to the face of the child during normal tidal breathing, and force and flow were recorded. This was repeated three times. A video of the procedure was made and scored on cooperation (scale of 1-5).

RESULTS

Mean application force was 4 N (± 1.5) equal to 411 g (± 156) when expressed as a weight equivalent; intrasubject variability in application force was 23% (± 23); intersubject variability in application force was 39%; time needed to empty the VHC was 4.5 sec (± 2.9); breaths needed to empty the VHC were 2.9 (± 1.1); and mean cooperation score was 4.3 (± 0.8). Age was correlated with time (r=-0.49; p=0.006) and breaths needed to empty the VHC (r=-0.75; p<0.001), and observer cooperation score (r=0.65; p<0.001).

CONCLUSIONS

The Facemask Datalogger is useful for measuring application force and air flow in vivo. Mean application force was lower than assumed in other studies. Older children emptied the VHC faster, with fewer breaths and better cooperation. The data from this study can be used in the future development and testing of new facemasks and VHCs.

Pediatric in vitro and in silico models of deposition via oral and nasal inhalation

Respiratory tract deposition models provide a useful method for optimizing the design and administration of inhaled pharmaceutical aerosols, and can be useful for estimating exposure risks to inhaled particulate matter. As aerosol must first pass through the extrathoracic region prior to reaching the lungs, deposition in this region plays an important role in both cases. Compared to adults, much less extrathoracic deposition data are available with pediatric subjects. Recently, progress in magnetic resonance imaging and computed tomography scans to develop pediatric extrathoracic airway replicas has facilitated addressing this issue. Indeed, the use of realistic replicas for benchtop inhaler testing is now relatively common during the development and in vitro evaluation of pediatric respiratory drug delivery devices. Recently, in vitro empirical modeling studies using a moderate number of these realistic replicas have related airway geometry, particle size, fluid properties, and flow rate to extrathoracic deposition. Idealized geometries provide a standardized platform for inhaler testing and exposure risk assessment and have been designed to mimic average in vitro deposition in infants and children by replicating representative average geometrical dimensions. In silico mathematical models have used morphometric data and aerosol physics to illustrate the relative importance of different deposition mechanisms on respiratory tract deposition. Computational fluid dynamics simulations allow for the quantification of local deposition patterns and an in-depth examination of aerosol behavior in the respiratory tract. Recent studies have used both in vitro and in silico deposition measurements in realistic pediatric airway geometries to some success. This article reviews the current understanding of pediatric in vitro and in silico deposition modeling via oral and nasal inhalation.

Interactions between caregivers and young children: exploring pedagogical tact in nebulizer treatment

Although research in health care suggests that one of the most important factors for efficient medical delivery is the child's willingness to cooperate, little is known about how caregivers facilitate cooperation with young children during medical treatment. In this article, we explore interactions between parents, nurses, and young children during pediatric nebulizer treatment in terms of tact as a pedagogical concept. Based on our analysis, which followed a hermeneutic approach and included video observations of five hospitalized children aged between 15 and 30 months, we present four themes related to pedagogical tact of caregivers and children's willingness to cooperate, and discuss the role that medical products can play in this cooperation. The results benefit pediatric health personnel, as well as product designers.

The effects of extrafine beclometasone/formoterol (BDP/F) on lung function, dyspnea, hyperinflation, and airway geometry in COPD patients: novel insight using functional respiratory imaging

BACKGROUND

The efficacy of inhaled corticosteroids (ICS) in moderately severe COPD patients remains unclear. At the same time, the use of extrafine particles in COPD patients is a topic of ongoing research.

OBJECTIVES

This study assessed the effect of ICS in steroid-naïve mild COPD patients and the effect of reducing the ICS dose in more severe COPD patients previously using ICS when switching to an extrafine particle BDP/F formulation (Foster using Modulite technology, Chiesi Pharmaceutici, Parma, Italy).

METHODS

Novel functional respiratory imaging (FRI) methods, consisting of multi-slice CT scans and Computational Fluid Dynamics, were used in combination with conventional pulmonary function tests and patient reported outcomes.

RESULTS

The study showed that the administration of extrafine BDP/F after 4-6 h led to a significant improvement in lung function parameters and hyperinflation as determined by spirometry, body plethysmography, and functional respiratory imaging. After 6 months of treatment, it was observed that, compared to baseline, the hyperinflation on lobar level at total lung capacity was significantly reduced (-1.19±7.19 %p, p=0.009). In addition, a significant improvement in SGRQ symptom score was noted in the entire patient population. Patients who improved in terms of hyperinflation also improved their MMRC dyspnea score. CFD indicated a difference in regional deposition between extrafine and non-extrafine formulations with -11% extrathoracic deposition and up to +4% lobe deposition for the extrafine formulation.

CONCLUSIONS

The study showed that the administration of extrafine BDP/F improved lung function parameters and hyperinflation. Patients previously treated with ICS remained stable despite the lower dose, while ICS naïve patients improved in terms of lobar hyperinflation. FRI seems to be a sensitive biomarker to detect clinically relevant changes that are not detected by spirometry. The next step is to confirm these findings in a controlled trial.

Aerosol therapy in children: challenges and solutions

Using aerosolized medications for the treatment of children has gained importance over the years. However, aerosol drug delivery to infants and pediatrics is not an easy task as it has been influenced by many challenges. Most aerosol devices have been designed for use in adults not for children. Therefore, they require some critical assessment in device selection and often a level of adaptation for use with smaller children. It is well documented that each aerosol device and interface that have been used for the treatment of children has its own advantages and challenges in drug delivery. This paper provides a comprehensive review of dosing, drug-device combination, aerosol devices and interfaces used for drug delivery to children with pulmonary diseases. Solutions to the challenges with the aim of optimizing aerosol therapy in this patient population are also discussed.

[Inhaled medication in pediatrics]

Three different devices are available for inhaled medications in children: the pressurized metered dose inhalers (pMDIs, breath-actuator synchronized pMDI, and valved holding spacers), the dry powder inhalers, and the nebulizers. To choose the better device for a particular patient, a perfect knowledge of the available devices, of their mode of use, of their advantages and inconvenient is required. The use of a pMDI coupled to a valved holding spacer is the first mode of delivery to propose in children aged less than 6 years. After 6 years old, the DPIs may be proposed depending on the child's competences. At last, the nebulizations are indicated in some particular and severe indications, but new indications are appearing because of recent progresses.

Vibrating membrane devices deliver aerosols more efficient than standard devices: a study in a neonatal upper airway model

BACKGROUND

Aerosol therapy in preterm infants is challenging, as a very small proportion of the drug deposits in the lungs.

AIM

Our aim was to compare efficiency of standard devices with newer, more efficient aerosol delivery devices.

METHODS

Using salbutamol as a drug marker, we studied two prototypes of the investigational eFlow(®) nebulizer for babies (PARI Pharma GmbH), a jet nebulizer (Intersurgical(®) Cirrus(®)), and a pressurized metered dose inhaler (pMDI; GSK) with a detergent-coated holding chamber (AeroChamber(®) MV) in the premature infant nose throat-model (PrINT-model) of a 32-week preterm infant (1,750 g). A filter or an impactor was placed below the infant model's "trachea" to capture the drug dose or particle size, respectively, that would have been deposited in the lung.

RESULTS

Lung dose (percentage of nominal dose) was 1.5%, 6.8%, and 18.0-20.6% for the jet nebulizer, pMDI-holding chamber, and investigational eFlow nebulizers, respectively (p<0.001). Jet nebulizer residue was 69.4% and 10.7-13.9% for the investigational eFlow nebulizers (p<0.001). Adding an elbow extension between the eFlow and the model significantly lowered lung dose (p<0.001). A breathing pattern with lower tidal volume decreased deposition in the PrINT-model and device residue (p<0.05), but did not decrease lung dose.

CONCLUSIONS

In a model for infant aerosol inhalation, we confirmed low lung dose using jet nebulizers and pMDI-holding chambers, whereas newer, more specialized vibrating membrane devices, designed specifically for use in preterm infants, deliver up to 20 times more drug to the infant's lung.

In vitro comparison of heliox and oxygen in aerosol delivery using pediatric high flow nasal cannula

Drug administration via high flow nasal cannula (HFNC) has been described in pediatrics but the amount of albuterol delivery with an HFNC is not known. The purpose of this study is to quantify aerosol delivery with heliox and oxygen (O(2)) in a model of pediatric ventilation. A vibrating mesh nebulizer (Aeroneb Solo, Aerogen) was placed on the inspiratory inlet of a heated humidifier and heated wire circuit attached to a pediatric nasal cannula (Optiflow, Fisher & Paykel). Breathing parameters were tidal volume (V(t)) 100 ml, respiratory rate (RR) 20/min, and I-time of 1 sec. Albuterol sulfate (2.5 mg/3 ml) was administered through a pediatric HFNC with O(2) (100%) and heliox (80/20% mixture). A total of 12 runs, using O(2) and heliox were conducted at 3 and 6 L/min (n = 3). Drug was collected on an absolute filter, eluted and measured using spectrophotometry. The percent inhaled dose (mean ± SD) was similar with heliox and O(2) at 3 L/min (11.41 ± 1.54 and 10.65 ± 0.51, respectively; P = 0.465). However at 6 L/min drug deposition was ≥ 2-fold greater with heliox (5.42 ± 0.54) than O(2) (1.95 ± 0.50; P = 0.01). Using a pediatric model of HFNC, reducing delivered flow from 6 to 3 L/min increased inhaled albuterol delivery ≥ 2-fold but eliminated the increase in inhaled drug efficiency associated with heliox.

Aerosol drug delivery: developments in device design and clinical use

Aerosolised drugs are prescribed for use in a range of inhaler devices and systems. Delivering drugs by inhalation requires a formulation that can be successfully aerosolised and a delivery system that produces a useful aerosol of the drug; the particles or droplets need to be of sufficient size and mass to be carried to the distal lung or deposited on proximal airways to give rise to a therapeutic effect. Patients and caregivers must use and maintain these aerosol drug delivery devices correctly. In recent years, several technical innovations have led to aerosol drug delivery devices with efficient drug delivery and with novel features that take into account factors such as dose tracking, portability, materials of manufacture, breath actuation, the interface with the patient, combination therapies, and systemic delivery. These changes have improved performance in all four categories of devices: metered dose inhalers, spacers and holding chambers, dry powder inhalers, and nebulisers. Additionally, several therapies usually given by injection are now prescribed as aerosols for use in a range of drug delivery devices. In this Review, we discuss recent developments in the design and clinical use of aerosol devices over the past 10-15 years with an emphasis on the treatment of respiratory disorders.

Aerosol inhalation from spacers and valved holding chambers requires few tidal breaths for children

OBJECTIVE

The goal was to determine the number of breaths required to inhale salbutamol from different spacers/valved holding chambers (VHCs).

METHODS

Breathing patterns were recorded for 2- to 7-year-old children inhaling placebo from 4 different spacers/VHCs and were simulated by a flow generator. Drug delivery with different numbers of tidal breaths and with a single maximal breath was compared.

RESULTS

With tidal breathing, mean inhalation volumes were large, ranging from 384 mL to 445 mL. Mean values for drug delivery with an Aerochamber Plus (Trudell, London, Canada) were 40% (95% confidence interval [CI]: 34%-46%) and 41% (95% CI: 36%-47%) of the total dose with 2 and 9 tidal breaths, respectively. Mean drug delivery values with these breath numbers with a Funhaler (Visiomed, Perth, Australia) were 39% (95% CI: 34%-43%) and 38% (95% CI: 35%-42%), respectively. With a Volumatic (GlaxoSmithKline, Melbourne, Australia), mean drug delivery values with 2 and 9 tidal breaths were 37% (95% CI: 33%-41%) and 43% (95% CI: 40%-46%), respectively (P = .02); there was no significant difference in drug delivery with 3 versus 9 tidal breaths. With the modified soft drink bottle, drug delivery. Drug delivery was not improved with a single maximal breath with any device.

CONCLUSION

For young children, tidal breaths through a spacer/VHC were much larger than expected. Two tidal breaths were adequate for small-volume VHCs and a 500-mL modified soft drink bottle, and 3 tidal breaths were adequate for the larger Volumatic VHC.

Influência do choro e de padrões respiratórios na deposição de medicação inalatória em crianças

OBJETIVO: Verificar a influência do choro e de padrões respiratórios na eficácia da terapia inalatória em crianças. FONTES DE DADOS: busca sistemática por artigos científicos referentes ao tema nas bases de dados Cochrane Controlled Trials Data Base, MedLine e Science Direct, publicadas no período de 1994 a 2009. Utilizaram-se os descritores: "choro", "inalação", "aerossol", "trabalho respiratório" e "criança", nos idiomas português e inglês. SÍNTESE DE DADOS: Foram selecionados 13 artigos, 12 em inglês e um em português. A maioria dos trabalhos apresenta os efeitos da terapia inalatória em crianças, sem discutir a influência do choro e de diferentes padrões respiratórios sobre a deposição da medicação. Estudos que fizeram essa relação verificaram que a respiração e, principalmente, o choro reduzem a quantidade de fármaco que chega às vias aéreas periféricas. Autores discutem as diferenças anatômicas e fisiológicas do sistema respiratório da criança que podem interferir na eficácia da terapia inalatória. Porém, a maioria deles não analisa a influência qualitativa e quantitativa dos padrões respiratórios e do choro sobre a mecânica pulmonar. CONCLUSÕES: O choro e os padrões respiratórios influenciam na terapia inalatória, sendo atribuída ao choro a redução significativa da deposição medicamentosa nas vias aéreas. Pouco se sabe sobre o princípio determinante para a alteração do potencial de deposição, pois são escassas as evidências sobre o tema, apesar de sua relevância no manejo de afecções pulmonares da população pediátrica.