Age-associated factors influencing the efficacy of various forms of aerosol therapy

Aerosol therapy through high flow nasal cannula in pediatric patients

INTRODUCTION

High flow nasal cannula (HFNC) is increasingly used in pediatric patients suffering from respiratory failure. In some disease processes, patients may also benefit from aerosol therapy. Therefore, the use of HFNC to deliver aerosolized medications is a convenient and attractive option. Areas covered: This review aims to appraise available evidence concerning the efficiency of aerosol nebulized therapy delivery using HFNC in pediatric patients. Expert commentary: Delivery of aerosol particles is a very complex process and depends on the use of oxygen vs. heliox, nebulizer type and position within the HFNC circuit, patient's breathing effort and pattern, and more importantly cannula size and flow rates. Current in vitro evidence suggests the amount of aerosol delivery is likely to be very low at high flows. Clinical studies are limited in pediatric patients and given the limited clinical data, it is not possible to make recommendations for or against aerosol delivery through HFNC for pediatric patients.

Performance Comparisons of Jet and Mesh Nebulizers Using Different Interfaces in Simulated Spontaneously Breathing Adults and Children

BACKGROUND

Different types of nebulizers and interfaces are used for the treatment of adults and children with pulmonary diseases. The purpose of this study was to determine the efficiency of a mesh nebulizer (MN) with a proprietary adapter and a jet nebulizer (JN) under different configurations in adult and pediatric models of spontaneous breathing. We hypothesize that delivery efficiency of JN and MN will differ depending on the interface used during aerosol therapy in simulated spontaneously breathing adult and pediatric models. While we expect that aerosol delivery with JN will be less efficient than MN, we also hypothesize that lung deposition obtained with the adult lung model will be more than that with the pediatric lung model in all conditions tested in this study.

METHODS

A lung model using a teaching manikin connected to a sinusoidal pump via a collecting filter at the level of the bronchi simulating a spontaneously breathing adult (Vt 500 mL, RR 15 bpm, I:E ratio 1:2) or pediatric patient (Vt 150 mL, RR 25 bpm, I:E ratio 1:2). Albuterol sulfate (2.5 mg/3 mL) was aerosolized with JN (Mistymax 10, Airlife) or MN (Aerogen Solo(®), Aerogen) with the Adapter (Aerogen Solo(®) Adapter, Aerogen Ltd, Galway, Ireland) using mouthpiece, aerosol mask, and valved-mask in adults and the dragon mask, aerosol mask, and valved-mask in pediatrics (n=3). The Adapter, specifically designed for MN, was attached to all the interfaces used in this study with supplemental oxygen of 2 lpm, and in addition, the MP was tested with no additional flow in the adult model. The JN was driven with 10 lpm based on the manufacturer's label. Drug was eluted from the filter and analyzed via spectrophotometry. Descriptive statistics, dependent t-test and one-way analysis of variance were used for data analysis. Significant level was set at 0.05.

RESULTS

In adults, delivery efficiency of JN with the valved mask was significantly greater than that with the aerosol mask (p=0.01). Aerosol delivery of JN with the mouthpiece was not statistically significant from the valved mask (p=0.123) and the aerosol mask (p=0.193). Drug delivery with MN with mouthpiece (15.42±1.4%) and valved-mask (15.15±1.1%) was greater than the open aerosol mask (7.54±0.39%; p=0.0001) in the adult lung model. With no flow mouthpiece delivery increased>2 fold (34.9±3.1%; p=.0001) compared to use of 2 lpm of flow. Using the JN with the pediatric model deposition with valved-mask (5.3±0.8%), dragon mask (4.7±0.9%), and aerosol mask (4.1±0.3%) were similar (p>0.05); while drug delivery with MN via valved-mask (11.1±0.7%) was greater than the dragon mask (6.44±0.3%; p=0.002) and aerosol mask (4.6±0.4%; p=0.002), and the dragon mask was more efficient than the open aerosol mask (p=0.009) CONCLUSION: The type of nebulizer and interface used for aerosol therapy affects delivery efficiency in these simulated spontaneously breathing adult and pediatric models. Drug delivery was greatest with the valved-mouthpiece and mask with JN and MN, while the standard aerosol mask was least efficient in these simulated spontaneously breathing adult and pediatric lung models. Delivery efficiency of JN was less than MN in all conditions tested in this study except in the aerosol mask. Lung deposition obtained with the adult lung model was more than that with the pediatric lung model.

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.

Clinical practice of nebulized therapy in China: a national questionnaire survey

BACKGROUND

Despite having been used in the clinical practice of respiratory diseases for decades in China, the overall description of nebulized therapy has not been reported to date. The purpose of this study was to investigate the basic characteristics and information on the application of nebulized therapy in the clinical practice of respiratory diseases in China.

METHODS

A questionnaire survey with 17 questions relating to nebulized therapy was carried out in three levels (tertiary, secondary, and primary) of hospitals throughout mainland China. The perspectives of various professional degrees of the medical staffs from different levels of hospitals were further studied.

RESULTS

A total of 6,449 effective questionnaires were collected from 1,328 hospitals or clinics located in 27 provinces or autonomous regions of mainland China. Nebulized therapy was applied in 91.1% of the hospitals, significantly more in tertiary and secondary levels of hospitals than in the primary level of hospitals. Jet and ultrasonic nebulizers were used in 53.3% and 47.7% of the hospitals, respectively. Only 50.8% of the responders identified the brands of the devices. 82.5 Percent of the responders had prescribed nebulized therapy. 68.8 Percent and 41.5% of responders agreed that nebulized therapy can be used for the treatment of asthma and COPD, respectively. 86.5 Percent of responders agreed that nebulized therapy can be used for patients with acute exacerbation, whereas 27.5% stated that it can be used for stable patients. The most commonly used medicines were short-acting bronchodilators, followed by corticosteroids, mucolytics, and antibiotics. 17.2 Percent of the responders reported adverse events of nebulized therapy experienced by the patients. Continuous medical education and training on nebulized therapy were required by 72.1% of responders.

CONCLUSIONS

The present national survey, firstly, provided the basic characteristics and information on the application of nebulizer therapy in the clinical practice of respiratory diseases in China. Certainly, this will help facilitate nebulized therapy, especially in the community hospitals. Continuous medical education and technical training are essential to improve the clinical application of nebulized therapy.

Personalizing aerosol medicine: development of delivery systems tailored to the individual

Inhalation of drugs for therapeutic effects is not a recent innovation as illicit drugs have been ‘smoked’ for millennia. Nicotine delivery ‘devices’ in convenient packaged cartons of cigarettes are simple to use, inexpensive per dose and accessible to people of most ages and lung function, but of course their use leads to increased cancer, emphysema, heart disease and other medical and societal problems. In contrast, many inhalation pharmaceutical medical devices are expensive, nonportable, inconvenient, and/or are used improperly thus leading to poor therapeutic benefit. We review the current state of the art with respect to aerosol delivery, inhalation devices and the ability to personalize the treatment and management of lung disease. The confluence of many drivers will lead to more programmable and flexible devices in the future: the transition from the blockbuster model to customized therapy, technological advancements (e.g., smartphones) and cultural changes including social networking.