In vitro comparison of a vibrating mesh nebulizer operating in inspiratory synchronized and continuous nebulization modes during noninvasive ventilation

Backround: Coupling nebulization with noninvasive ventilation (NIV) has been shown to be effective in patients with respiratory diseases. However, a breath-synchronized nebulization option that could potentially improve drug delivery by limiting drug loss during exhalation is currently not available on bilevel ventilators. The aim of this in vitro study was to compare aerosol delivery of amikacin with a vibrating mesh nebulizer coupled to a single-limb circuit bilevel ventilator, using conventional continuous (Conti-Neb) and experimental inspiratory synchronized (Inspi-Neb) nebulization modes. Methods: Using an adult lung bench model of NIV, we tested a vibrating mesh device coupled with a bilevel ventilator in both nebulization modes. Inspi-Neb delivered aerosol only during the whole inspiratory phase, whereas Conti-Neb delivered aerosol continuously. The nebulizer was charged with amikacin solution (250 mg/3 mL) and placed at two different positions: between the lung and exhalation port and between the ventilator and exhalation port. Inhaled, expiratory wasted and circuit lost doses were assessed by residual gravimetric method. Particle size distribution of aerosol delivered at the outlet of the ventilator circuit during both nebulization modes was measured by laser diffraction method. Results: Regardless of the nebulizer position, Inspi-Neb produced higher inhaled dose ( p < 0.01; +6.3% to +16.8% of the nominal dose), lower expiratory wasted dose ( p < 0.05; -2.7% to -42.6% of the nominal dose), and greater respirable dose ( p < 0.01; +8.4% to +15.2% of the nominal dose) than Conti-Neb. The highest respirable dose was found with the nebulizer placed between the lung and exhalation port (48.7% – 0.3% of the nominal dose). Conclusions: During simulated NIV with a single-limb circuit bilevel ventilator, the use of inspiratory synchronized vibrating mesh nebulization improves respirable dose and reduces drug loss of amikacin compared with continuous vibrating mesh nebulization

Cystic fibrosis in the modern therapeutic era: Give the shower a thought!

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Deposition of aerosols delivered by nasal route with jet and mesh nebulizers

PURPOSE: To quantify the amount of aerosol deposited in different parts of the airways with a commercially available nasal sonic jet nebulizer (NJN) using a sound effect, and to compare its performance with a new nasal mesh nebulizer (NMN). METHODS: Seven healthy non-smoking male volunteers aged 21-36 years with a mean weight of 77±10 kg were included in this single-center study. Both nebulizer systems were loaded with (99m)Tc-DTPA and scintigraphies were performed with a gamma camera. Particle size distribution of the aerosols produced by the two nebulizer systems was measured. RESULTS: There was no statistical difference between the two nebulizers in terms of fraction of particles smaller than 5 μm (44±4% vs 45±2%) (p>0.9). Aerosol deposition in the nasal region was 73±10% (% of aerosol deposited in airways) with the NJN, and 99±3% with the NMN (p=0.01). Total nasal deposition was 9.6±1.9% of the nebulizer charge with the NJN and 28.4±8.9% with the NMN (p=0.01). 0.5±0.3% of the nebulizer charge was deposited in the maxillary sinuses with the NJN, compared to 2.2±1.6% with the NMN (p=0.01). CONCLUSION: Although the two nebulizers had the same particle size, NMN significantly improved aerosol deposition in nasal cavity and prevents deposition into the lungs

Nasal high flow nebulization in infants and toddlers: An in vitro and in vivo scintigraphic study

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Pre-eruptive physical conditions of El Reventador volcano (Ecuador) inferred from the petrology of the 2002 and 2004–05 eruptions

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Pre-eruptive physical conditions of El Reventador volcano (Ecuador) inferred from the petrology of the 2002 and 2004-05 eruptions

A petrological study of the eruptive products of El Reventador allowed us to infer the magmatic processes related to the 2002 and 2004-05 eruptions of this andesitic stratovolcano. On November 3, 2002, El Reventador experienced a highly explosive event, which was followed by emplacement of two lava flows in November-December 2002. Silica contents range from 62 to 58 wt.% SiO2 for the November 3 pyroclastic deposits to 58-56 and 54-53 wt.% SiO2 for the successive lava flows. In November 2004 eruptive activity resumed supplying four new lava flows (56-54 wt.% SiO2) between November 2004 and August 2005. Volatile contents in matrix glasses and glass inclusions from the November 3 pyroclastic deposits allow us to estimate the total amount of SO2 and HCl released into the atmosphere during the paroxysmal phase (i.e. 80 kT of SO2 and 280 kT of HCl). Pre-eruptive pressure-temperature conditions of the magmas range from 300 to 150 MPa and similar to 1000 degrees C with high water contents (similar to 5 wt.%). We propose the existence of an andesitic magma body located at similar to 7-12 km depth that is frequently intruded by more primitive, hydrous magmas from a deeper source. The initial crystallization of amphibole from the hydrous primitive magma seems typical of El Reventador, as well as the historically recurrent and regular periods of eruptive activity lasting several years. This eruptive behaviour coupled with the fractionation and mixing processes inferred from the 2002 and 2004-05 petrologic data suggest that deep magmatic recharge at El Reventador is frequent, and is probably responsible for the high frequency of eruptions

In Vitro Comparison of a Vibrating Mesh Nebulizer Operating in Inspiratory Synchronized and Continuous Nebulization Modes During Noninvasive Ventilation

BACKGROUND: Coupling nebulization with noninvasive ventilation (NIV) has been shown to be effective in patients with respiratory diseases. However, a breath-synchronized nebulization option that could potentially improve drug delivery by limiting drug loss during exhalation is currently not available on bilevel ventilators. The aim of this in vitro study was to compare aerosol delivery of amikacin with a vibrating mesh nebulizer coupled to a single-limb circuit bilevel ventilator, using conventional continuous (Conti-Neb) and experimental inspiratory synchronized (Inspi-Neb) nebulization modes. METHODS: Using an adult lung bench model of NIV, we tested a vibrating mesh device coupled with a bilevel ventilator in both nebulization modes. Inspi-Neb delivered aerosol only during the whole inspiratory phase, whereas Conti-Neb delivered aerosol continuously. The nebulizer was charged with amikacin solution (250 mg/3 mL) and placed at two different positions: between the lung and exhalation port and between the ventilator and exhalation port. Inhaled, expiratory wasted and circuit lost doses were assessed by residual gravimetric method. Particle size distribution of aerosol delivered at the outlet of the ventilator circuit during both nebulization modes was measured by laser diffraction method. RESULTS: Regardless of the nebulizer position, Inspi-Neb produced higher inhaled dose (p < 0.01; +6.3% to +16.8% of the nominal dose), lower expiratory wasted dose (p < 0.05; -2.7% to -42.6% of the nominal dose), and greater respirable dose (p < 0.01; +8.4% to +15.2% of the nominal dose) than Conti-Neb. The highest respirable dose was found with the nebulizer placed between the lung and exhalation port (48.7% ± 0.3% of the nominal dose). CONCLUSIONS: During simulated NIV with a single-limb circuit bilevel ventilator, the use of inspiratory synchronized vibrating mesh nebulization improves respirable dose and reduces drug loss of amikacin compared with continuous vibrating mesh nebulization

Validation Of Anatomical Models To Study Aerosol Deposition In Human Nasal Cavities

International audiencePurposeIntranasal deposition of aerosols is often studied using in vitro nasal cavity models. However, the relevance of these models to predict in vivo human deposition has not been validated. This study compared in vivo nasal aerosol deposition and in vitro deposition in a human plastinated head model (NC1) and its replica constructed from CT-scan (NC2).MethodsTwo nebulizers (Atomisor Sonique® and Easynose®) were used to administer a 5.6 μm aerosol of 99mTc-DTPA to seven healthy volunteers and to the nasal models. Aerosol deposition was quantified by γ-scintigraphy in the nasal, upper nasal cavity and maxillary sinus (MS) regions. The distribution of aerosol deposition was determined along three nasal cavity axes (x, y and z).ResultsThere was no significant difference regarding aerosol deposition between the volunteers and NC1. Aerosol deposition was significantly lower in NC2 than in volunteers regarding nasal region (p < 0.05) but was similar for the upper nasal cavity and MS regions. Mean aerosol distribution for NC1 came within the standard deviation (SD) of in vivo distribution, whereas that of NC2 was outside the in vivo SD for x and y axes.ConclusionsIn conclusion, nasal models can be used to predict aerosol deposition produced by nebulizers, but their performance depends on their design

Nasal high-flow bronchodilator nebulization: a randomized cross-over study

Abstract Background There is an absence of controlled clinical data showing bronchodilation effectiveness after nebulization via nasal high-flow therapy circuits. Results Twenty-five patients with reversible airflow obstruction received, in a randomized order: (1) 2.5 mg albuterol delivered via a jet nebulizer with a facial mask; (2) 2.5 mg albuterol delivered via a vibrating mesh nebulizer placed downstream of a nasal high-flow humidification chamber (30 L/min and 37 °C); and (3) nasal high-flow therapy without nebulization. All three conditions induced significant individual increases in forced expiratory volume in one second (FEV1) compared to baseline. The median change was similar after facial mask nebulization [+ 350 mL (+ 180; + 550); + 18% (+ 8; + 30)] and nasal high flow with nebulization [+ 330 mL (+ 140; + 390); + 16% (+ 5; + 24)], p = 0.11. However, it was significantly lower after nasal high-flow therapy without nebulization [+ 50 mL (− 10; + 220); + 3% (− 1; + 8)], p = 0.0009. FEV1 increases after facial mask and nasal high-flow nebulization as well as residual volume decreases were well correlated (p < 0.0001 and p = 0.01). Both techniques showed good agreement in terms of airflow obstruction reversibility (kappa 0.60). Conclusion Albuterol vibrating mesh nebulization within a nasal high-flow circuit induces similar bronchodilation to standard facial mask jet nebulization. Beyond pharmacological bronchodilation, nasal high flow by itself may induce small but significant bronchodilation