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\u27s 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\u3e2 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\u3e0.05); 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

Diagnostic accuracy of exhaled nitric oxide in exercise-induced bronchospasm: Systematic review

Introduction: The gold-standard method for the diagnosis of exercise-induced bronchospasm (EIB) is an exercise test combined with spirometry. However, this test is expensive, time consuming and requires specialized equipment and trained personnel. Exhaled nitric oxide (eNO) is a fast, easy, noninvasive method for the diagnosis of EIB. The aim of the present study was to assess the accuracy of the measurement of eNO for the diagnosis of EIB through a systematic review of the literature. Methods: A search was carried out in the PubMed, Lilacs, SciELO and SCOPUS databases by two independent researchers. Results: Fifty-six papers were found. Following the application of the eligibility criteria to the title, abstract and text, six papers remained for analysis. There was a significant heterogeneity in sex (X2 = 56.44, p = 0.000) and clinical spectrum (X2 = 504.00, p = 0.000) between studies. In children between 3.8 and 7.8 years old a cutoff point >28 ppb EIB can be ruled in and in children between 5 and 16 years old at a cutoff point <20 EIB can be ruled out. For adults a cutoff point <7 EIB can be ruled out and it can be ruled in with a cutoff point >12. Four papers reported negative predictive values above 88%. Conclusion: The measurement of eNO seems to be effective for ruling in and ruling out EIB in some specific groups. Therefore, the meansurement of eNO levels could be an important tool to safely avoid the need for an exercise test when the result is negative, reducing the individual and economic impact of this disease. Resumo: Introdução: O método padrão de ouro para o diagnóstico de broncoespasmos induzidos por exercício (BIE) é a prova de esforço combinada com a espirometria. Contudo, esta prova é dispendiosa, demorada e requer equipamento específico e pessoal especializado. O óxido nítrico exalado (eNO) é um método rápido, simples e não invasivo para o diagnóstico de BIE. O objectivo do presente estudo foi o de aferir a acurácia do eNO para o diagnóstico do BIE através da revisão sistemática da literatura. Métodos: Foi efectuada uma pesquisa nas bases de dados PubMed, Lilacs, SciELO e SCOPUS por dois investigadores independentes. Resultados: Foram encontrados 56 artigos e após as exclusões pelo título, resumo e texto, restaram 6 artigos para análise. Foi encontrada heterogeneidade significativa entre os estudos quanto ao sexo (X2=56,44; p=0,000) e ao espectro clínico (X2 =504,00; p=0,000). Em crianças com idades entre os 3,8 e os 7,8 anos o ponto de corte >28 ppb pode considerar o BIE presente, e em crianças com idades entre os 5 e os 16 anos o ponto de corte <20 BIE poderá excluir essa afecção. Para adultos o BIE poderá ser excluído quando o ponto de corte for <7 BIE e o ponto de corte >12 poderá considerar a presença da doença. Quatro artigos registaram valores preditores negativos acima dos 88%. Conclusão: A avaliação do eNO parece ser eficaz na inclusão ou na exclusão de BIE em alguns grupos específicos. Assim sendo, a avaliação dos níveis de eNO poderá ser uma ferramenta segura para evitar a necessidade da prova de esforço nos casos negativos, reduzindo a impacto individual e económico desta doença. Keywords: Exercise-induced asthma, Diagnosis, Sensitivity and specificity, Nitric oxide, Palavras-chave: Asma induzida por exercício, diagnóstico, sensibilidade e especificidade, óxido nítric