Interchanging Reusable and Disposable Nebulizers Used with Home-Based Compressors May Result in Inconsistent Dosing: A Laboratory Investigation with Device Combinations Supplied to the US Healthcare Environment

INTRODUCTION

Reusable nebulizer-compressor combinations deliver inhaled medications for patients with chronic lung diseases. On hospital discharge, the patient may take home the disposable nebulizer that was packaged and combine it with their home compressor. Though this practice may reduce waste, it can increase variability in medication delivery. Our study compared several reusable and disposable nebulizers packaged with compressor kits used in the US. We included a common disposable hospital nebulizer that may not be supplied with popular home kits but may be brought home after a hospitalization or emergency department visit. We focused on fine droplet mass < 4.7 μm aerodynamic diameter (FDM<4.7 μm), associated with medication delivery to the airways of the lungs.

METHODS

We evaluated the following nebulizer-compressor combinations (n = 5 replicates): 1. OMBRA® Table Top Compressor with MC 300® reusable and Airlife™ MistyMax™ 10® disposable nebulizer, 2. Sami-the-Seal® compressor with SideStream® reusable and disposable nebulizers and Airlife™ MistyMax 10™ disposable nebulizer, 3. VIOS® compressor with LC Sprint® reusable, and VixOne® and Airlife™ MistyMax™ disposable nebulizers, 4. Innospire® Elegance® compressor with SideStream® reusable and disposable nebulizers and Airlife™ MistyMax 10™ disposable nebulizer, 5. Willis-the-Whale® compressor with SideStream® reusable and disposable nebulizers and Airlife™ MistyMax 10™ disposable nebulizer, 6. Pari PRONEB® Max compressor with LC Sprint® reusable and Airlife™ MistyMax 10™ disposable nebulizer. We placed a 3-ml albuterol solution (0.833 mg/ml) in each nebulizer. A bacterial/viral filter was attached to the nebulizer mouthpiece to capture emitted medication, with the filter exit coupled to a simulator of a tidal breathing adult (rate = 10 cycles/min; Vt = 600 ml; I/E ratio = 1:2). The filter was replaced at 1-min intervals until onset of sputter. Droplet size distributions (n = 5 replicates/system) were determined in parallel by laser diffractometry.

RESULTS

Cumulative FDM<4.7 μm varied from 381 ± 33 μg for the best performing combination (Proneb/LC-Sprint) to 150 ± 21 μg for the system with the lowest output (VIOS®/MistyMax 10™).

CONCLUSIONS

Substituting one nebulizer for another can result in large differences in medication delivery to the lungs.

Nebulizers effectiveness on pulmonary delivery of alpha-1 antitrypsin

The nebulization of alpha-1 antitrypsin (AAT) for its administration to the lung could be an interesting alternative to parenteral infusion for patients suffering from AAT genetic deficiency (AATD). In the case of protein therapeutics, the effect of the nebulization mode and rate on protein conformation and activity must be carefully considered. In this paper two types of nebulizers, i.e., a jet and a mesh vibrating system, were used to nebulize a commercial preparation of AAT for infusion and compared. The aerosolization performance, in terms of mass distribution, respirable fraction, and drug delivery efficiency, as well as the activity and aggregation state of AAT upon in vitro nebulization were investigated. The two nebulizers demonstrated equivalent aerosolization performances, but the mesh nebulizer provided a higher efficiency in the delivery of the dose. The activity of the protein was acceptably preserved by both nebulizers and no aggregation or changes in its conformation were identified. This suggests that nebulization of AAT represents a suitable administration strategy ready to be translated to the clinical practice for delivering the protein directly to the lungs in AATD patients, either as a support therapy to parenteral administration or for subjects with a precocious diagnosis, to prevent the onset of pulmonary symptoms.

A path forward in the development of new aerosol drug delivery devices for pediatrics

Inhaled medications are widely accepted as being the optimal route for treating pediatric respiratory diseases, a leading cause of hospitalization and death. Despite jet nebulizers being the preferred inhalation device for neonates and infants, current devices face performance issues with most of the drug never reaching the target lung location. Previous work has aimed to improve pulmonary drug deposition, yet nebulizer efficiency remains low. The development of an inhalant therapy that is efficacious and safe for pediatrics depends on a well-designed delivery system and formulation. To accomplish this, the field needs to rethink the current practice of basing pediatric treatments on adult studies. The rapidly evolving pediatric patient (i.e. neonates to eighteen) needs to be considered because they are different from adults with respect to airway anatomy, breathing patterns, and adherence. Previous research approaches to improve deposition efficiency have been limited due to the complexity of combining physics, which drives aerosol transport and deposition, and biology, especially within the area of pediatrics. To address these critical knowledge gaps, we need a better understanding of how patient age and disease state affect deposition of aerosolized drugs. The complexity of the multiscale respiratory system makes scientific investigation very challenging. The authors have simplified the complex problem into five components with these three areas as ones to address first: how the aerosol is (i) generated in a medical device, (ii) delivered to the patient, and (iii) deposited inside the lung. In this review, we discuss the technological advances and innovations made from experiments, simulations, and predictive models in each of these areas. In addition, we discuss the impact on patient treatment efficacy and recommend a clinical direction, with a focus on pediatrics. In each area, a series of research questions are posed and steps for future research to improve efficacy in aerosol drug delivery are outlined.

Effect of functional principle, delivery technique, and connection used on aerosol delivery from different nebulizers: An in-vitro study

OBJECTIVE

Nebulizers can be divided according to their functional principle into jet, ultrasonic and vibrating mesh nebulizers with intermittent or continuous aerosol delivery and may be used with many different adapters and connections and all can influence their efficiency. The aim of the present work was to evaluate the effect functional principle, delivery technique, and connection used on aerosol delivered from four different nebulizers.

METHODS

Four nebulizers were used in the study; three of them were jet nebulizers (JNs; AeroEclipse, NebuTech, En ful Kit) and one of them was Aerogen Solo vibrating mesh nebulizers (VMN). AeroEclipse and NebuTech are intermittent output nebulizers, while the rest are continuous output nebulizers. Aerogen Solo was used with either a standard T-piece or Aerogen Ultra holding chamber, and En ful Kit was used with a standard T-piece or Circulaire II holding chamber. 2 ml of salbutamol was nebulized to determine the total emitted dose (TED) and aerodynamic droplet characteristics of the emitted aerosol from the 6 different sets (4 nebulizers with T-piece and 2 holding chambers).

RESULTS

The mean ± SD TED from VMN was significantly higher than all the JNs (p < 0.05). Aerogen Ultra with VMN did not show a significant effect on TED compare to T-piece, but it significantly increased (p < 0.05) fine particle dose (FPD; 3091.5 ± 189.4 μg) and fine particle fraction (FPF; 72.7 ± 3.6%). However, the Circulaire II with En ful Kit had significantly higher TED, FPD, and FPF compared to T-piece (p < 0.05). Intermittent JNs (AeroEclipse and NebuTech) had significantly higher TED (p < 0.05) compared to the continuous JNs (En ful Kit) with no significant effect on the other parameters studied. AeroEclipse had the highest MMAD and Aerogen Solo Ultra has the lowest in MMAD.

CONCLUSIONS

The functional principle, delivery technique, and connection used had a significant effect on aerosol delivered from nebulizers. VMNs are significantly better than JNs. Intermittent delivery has significantly better TED than continuous delivery. Holding chamber with both VMNs and JNs improved aerosol delivery compared to standard T-piece.

An Automated Jet Nebulizer with Dynamic Flow Regulation

Purpose

The present study is focused on designing an automated jet nebulizer that possesses the capability of dynamic flow regulation. In the case of existing equipment, 50% of the aerosol is lost to the atmosphere through the vent, during the exhalation phase of respiration. Desired effects of nebulization may not be achieved by neglecting this poor administration technique. There may be adverse effects like bronchospasm and exposure to high drug concentrations.

Methods

The proposed nebulizer is composed of two modes as "Compressed Air" mode and the "Oxygen Therapy" mode. The automated triggering from one mode to another will be dependent upon the percentage of oxygen saturation of the patient, monitored from the SpO₂ sensor. The compressed airflow will be delivered to the patient according to the minute ventilation, derived with the aid of a temperature sensor-based algorithm. The compressor controller circuitry ensures that the patient receives optimum level of compressed air as per the flow rate. At the end of the drug delivery, if the liquid level sensor detects the absence of medication within the nebulizer chamber, the nebulization process will be terminated. The dynamic regulation of the motor speed with respect to the minute ventilation was accomplished.

Results

A laminar flow was obtained from the outlet of the compressor towards the nebulizer tubing, and a turbulent flow was obtained within the chamber. No excessive turbulent flows or rotational flow patterns were detected.

Conclusion

Detecting the drug levels in the nebulizing chamber will prevent continuous workup and useful in situations where back-to-back nebulization is required. Oxygen therapy mode identifies the patient's desaturation and important where the patient can be already hypoxic or have a ventilation-perfusion mismatch, but may be disadvantageous in severe COPD patients. The aforesaid results could certainly lead to the improvements of the existing nebulizers.

An in vitro investigation into the release of fugitive medical aerosols into the environment during manual ventilation

BACKGROUND

During manual resuscitation, nebulizer therapy may be used to deliver therapeutics to patients in respiratory distress. However, the devices used to generate and deliver these medical aerosols have the potential to release these therapeutics into the local environment and expose caregivers to unwanted medical aerosols.

AIM

To quantify the levels of fugitive medical aerosol released into the environment during aerosol drug delivery using a manual resuscitation bag with and without filtration.

METHODS

Time-varying fugitive aerosol concentrations were measured using an aerodynamic particle sizer placed at a position designed to mimic a caregiver. Two nebulizer types were assessed, a vibrating mesh nebulizer and a jet nebulizer. The aerosol dose delivered to the simulated patient lung was also quantified.

FINDINGS

Filtration of the exhalation port of the manual resuscitation bag was seen to reduce fugitive medical aerosols to ambient levels for both nebulizer types. The vibrating mesh nebulizer delivered the greatest quantity of aerosol to the simulated adult patient (18.44 ± 1.03% versus 3.64 ± 0.26% with a jet nebulizer).

CONCLUSIONS

The results highlight the potential for exposure to fugitive medical aerosols released during the delivery of aerosol therapy with a manual resuscitation bag and also the potential for significant variation in patient lung dose depending on nebulizer type.

A narrative review on trans-nasal pulmonary aerosol delivery

The use of trans-nasal pulmonary aerosol delivery via high-flow nasal cannula (HFNC) has expanded in recent years. However, various factors influencing aerosol delivery in this setting have not been precisely defined, and no consensus has emerged regarding the optimal techniques for aerosol delivery with HFNC. Based on a comprehensive literature search, we reviewed studies that assessed trans-nasal pulmonary aerosol delivery with HFNC by in vitro experiments, and in vivo, by radiolabeled, pharmacokinetic and pharmacodynamic studies. In these investigations, the type of nebulizer employed and its placement, carrier gas, the relationship between gas flow and patient’s inspiratory flow, aerosol delivery strategies (intermittent unit dose vs continuous administration by infusion pump), and open vs closed mouth breathing influenced aerosol delivery. The objective of this review was to provide rational recommendations for optimizing aerosol delivery with HFNC in various clinical settings.

A mesh nebulizer is more effective than jet nebulizer to nebulize bronchodilators during non-invasive ventilation of subjects with COPD: A randomized controlled trial with radiolabeled aerosols

BACKGROUND

Beneficial effects from non-invasive ventilation (NIV) in acute COPD are well-established, but the impact of nebulization during NIV has not been well described.

AIM

To compare pulmonary deposition and distribution across regions of interest with administration of radiolabeled aerosols generated by vibrating mesh nebulizers (VMN) and jet nebulizer (JN) during NIV.

METHODS

A crossover single dose study involving 9 stable subjects with moderate to severe COPD randomly allocated to receive aerosol administration by the VMN Aerogen and the MistyNeb jet nebulizer operating with oxygen at 8 lpm during NIV. Radiolabeled bronchodilators (fill volume of 3 mL: 0.5 mL salbutamol 2.5 mg + 0.125 mL ipratropium 0.25 mg and physiologic saline up to 3 mL) were delivered until sputtering during NIV (pressures of 12 cmH2O and 5 cmH2O - inspiratory and expiratory, respectively) using an oro-nasal facemask. Radioactivity counts were performed using a gamma camera and regions of interest (ROIs) were delimited. Aerosol mass balance based on counts from the lungs, upper airways, stomach, nebulizer, circuit, inspiratory and expiratory filters, and mask were determined and expressed as a percentage of the total.

RESULTS

Both inhaled and lung doses were greater with VMN (22.78 ± 3.38% and 12.05 ± 2.96%, respectively) than JN (12.51 ± 6.31% and 3.14 ± 1.71%; p = 0.008). Residual drug volume was lower in VMN than in JN (3.08 ± 1.3% versus 46.44 ± 5.83%, p = 0.001). Peripheral deposition of radioaerosol was significantly lower with JN than VMN.

CONCLUSIONS

VMN deposited > 3 fold more radioaerosol into the lungs of moderate to severe COPD patients than JN during NIV.

A comparative in vitro study of standard facemask jet nebulization and high-flow nebulization in bronchiolitis

Aim of Study: The use of a nebulizer paired with high-flow nasal cannulas (HFNC) has been proposed for drug delivery in bronchiolitis. Particle size nebulized is a relevant factor determining the efficacy of the nebulization. We replicated in vitro the theoretical parameters most widely used in bronchiolitis and we compared the size of the droplet nebulized with a standard nebulizer and a nebulizer integrated into HFNC. Materials and Methods: We used laser diffraction to analyze the particle size nebulized (volume median diameter Dv50). The standard system was a jet nebulizer connected to a facemask with a flow rate of 8 L/min (JN). Three designs were used as nebulizers integrated into HFNC: a vibrating mesh nebulizer set 1) before (HFNC-BH) and 2) after (HFNC-AH) the humidifier, and 3) a jet nebulizer connected before the nasal cannula (HFNC-BNC). HFNC was used with neonatal (3-8 L/min) and infant cannulas (8-15 L/min). Results: Droplet size was similar among the three drugs studied. A lower particle size was obtained when using the nebulization system integrated into HFNC compared to the standard nebulizer, regardless of the flow rate and the nasal cannula used when the position of the nebulizer was before the nasal cannula (p < 0.05): 6.89 µm (JN), 2.49 µm (HFNC-BNC 3 L/min), 2.59 µm (HFNC-BNC 5 L/min), 2.44 µm (HFNC-BNC 8 L/min), 3.22 µm (HFNC-BNC 10 L/min), 3.23 µm (HFNC-BNC 13 L/min), 3.16 µm (HFNC-BNC 15 L/min). The particle size was lower in HFNC-BF compared to the HFNC-AH using neonatal nasal cannula (3-8 L/min) (p < 0.05). Conclusion: The use of a nebulizer integrated with HFNC has shown promising results in an experimental scenario of bronchiolitis. The particle size achieved with the nebulizer placed before the humidifier is equivalent to the one obtained via conventional nebulization, and it is even smaller when the integrated nebulizer is placed before the nasal cannulas.

Comparison of bronchodilator administration with vibrating mesh nebulizer and standard jet nebulizer in the emergency department

INTRODUCTION

Projects comparing bronchodilator response by aerosol devices in the ED are limited. Evidence suggests that the vibrating mesh nebulizer (VMN) provides 5-fold greater aerosol delivery to the lung as compared to a jet nebulizer (JN). The aim of this project was to evaluate a new nebulizer deployed in an Emergency Department.

METHODS

A quality improvement evaluation using a prospectively identified data set from the electronic medical record comparing all ED patients receiving aerosolized bronchodilators with the JN during September 2015 to those receiving aerosolized bronchodilators with the VMN during October 2015.

RESULTS

1594 records were extracted, 879 patients received bronchodilators via JN and 715 patients via the VMN. Admission rates in the VMN group were 28.1% and in the JN group at 41.4%. The total albuterol dose administered was significantly lower in the VMN group compared to the JN (p<0.001). No patient in the VMN group required >5mg albuterol to control symptoms (85% of the VMN group received only 2.5mg) whereas dosing in the JN group was higher in some patients (with 47% receiving only 2.5mg). The use of VMN was also associated with a 13% (37min) reduction in median length of stay in the ED.

CONCLUSIONS

The VMN was associated with fewer admissions to the hospital, shorter length of stay in the ED and a reduction in albuterol dose. The device type was a predictor of discharge, disposition and amount of drug used. Randomized controlled studies are needed to corroborate these findings.