This study was supported by the Reginald Jenney Endowment Chair at Harvard Medical School to L.B., by L.B. Sundry Funds at MGH, and by laboratory funds of the Anesthesia Center for Critical Care Research of the Department of Anesthesia, Critical Care and Pain Medicine at MGH.

NOTE: See the Table of Materials for the materials needed to assemble the delivery system. Sources of medical air, O2, and NO gases should also be available on site. The device has been developed for investigation use in research protocols that underwent rigorous review by the local Institutional Review Board (IRB). Under no circumstances should providers operate solely based on the indications included in this manuscript, assembling and using this device without seeking prior appropriate institutional regulatory approval. Starting from the proximal end of the device, assemble the pieces in the following order (Figure 1).
1. Building the patient interface
<ol>
	<li>Take a snug-fitting, standard, non-invasive ventilation face mask of the appropriate size for the subject.</li>
	<li>Connect the mask&#39;s built-in elbow port to a high-efficiency particulate air (highly hydrophobic bacterial/viral filter, HEPA class 13) filter through the 22 mm outer diameter (O.D.)/15 mm inner diameter (I.D.) connector.</li>
	<li>(Optional) To facilitate the subject&#39;s movement and reduce the risk of disconnection, add a 15 mm O.D. x 22 mm O.D./15 mm I.D. (length 5 cm-6.5 cm) flexible patient connector for an endotracheal or tracheostomy tube between the mask interface and the HEPA filter. 
	&#8203;NOTE: Make every effort to avoid leakage of the mask interface. The &#34;patient end&#34; of the device could also consist of a mouthpiece. A nose clip must be added in such a configuration.</li>
</ol>
2. Building the Y-piece and preparation of the O2 supply
<ol>
	<li>Take a 22 mm to 22 mm and 15 F Y-piece connector with 7.6 mm ports. Create the circuit&#39;s expiratory and inspiratory limbs on the two distal ends of the Y-piece through two opposite-sense, low-resistance, 22 mm male/female, one-way valves.
	<ol>
		<li>Expiratory limb: On one end of the Y-piece, place the one-way valve connector allowing a proximal-to-distal flow only (arrow pointing downward).</li>
		<li>Inspiratory limb: On the other end of the Y-piece, connect a one-way valve allowing a distal-to-proximal flow only (arrow pointing upward).</li>
	</ol>
	</li>
	<li>Connect the proximal end of the Y to the HEPA filter.</li>
	<li>Using standard, kink-resistant, vinyl gas tubing with universal adaptors at both ends, connect the O2 source to the Y-piece&#39;s inspiratory limb. Choose tubing of appropriate length considering the distance between the patient and the source of the gas. 
	&#8203;NOTE: The Y-piece connector must have a sampling port on the inspiratory limb. If not, an additional straight connector with a sampling port must be used to supply O2.</li>
</ol>
3. Building and attaching the scavenging chamber
<ol>
	<li>Connect a 22 mm x 22 mm silicon rubber, flexible connector adapter to the proximal end of a scavenger chamber (internal diameter = 60 mm, internal length = 53 mm, volume = 150mL) containing 100 g of calcium hydroxide (Ca(OH)2).</li>
	<li>Attach a 15 mm O.D. x 22 mm O.D./15 mm I.D., 5 cm-6.5 cm, flexible, corrugated tube to the silicon rubber adapter.</li>
	<li>Connect another 22 mm x 22 mm silicon rubber, flexible connector adapter to the distal end of the scavenger.</li>
	<li>Add the scavenging chamber and tubing assembly to the Y piece&#39;s inspiratory limb using a 15 mm-22 mm two-step adapter.</li>
</ol>
4. Building and attaching the NO reservoir system
<ol>
	<li>Assemble a 3-L latex-free breathing reservoir bag and a 90&#176; ventilator elbow connector without ports (22 mm ID x 22 mm).</li>
	<li>Connect the other end of the elbow to the central opening of the aerosol T-piece (horizontal ports 22 mm O.D., vertical port 11 mm I.D./22 mm O.D.).</li>
	<li>Attach the T-piece to the scavenging chamber&#39;s distal end by advancing it until it fits the silicon rubber connector tightly.</li>
</ol>
5. Building the NO and medical air supply system
<ol>
	<li>Build the NO/air gas supply system by attaching two consecutive 15 mm O.D. x 15 mm I.D./22 mm O.D. connectors with 7.6 mm sampling ports and flip-top caps. 
	NOTE: Once the caps are removed, the sampling accesses will function as gas inlet ports.</li>
	<li>At the distal end of the NO/air supply system, attach another one-way inspiratory valve (arrow pointing upwards).</li>
	<li>At the proximal end of the NO/air supply system, connect a 15/22 mm two-step adapter.</li>
	<li>Connect the proximal two-step adapter to the remaining free inlet of the green T-piece from the NO reservoir system.</li>
</ol>
6. Attach the air and NO gas flow lines by using standard, kink-resistant, star-lumen vinyl oxygen gas tubing for the following steps.
<ol>
	<li>Connect medical air to the most distal gas inlet port.</li>
	<li>Connect NO gas from an 800 ppm medical-grade NO tank (size AQ aluminum cylinders containing 2239 L of 800 ppm of NO gas at standard temperature and pressure, balanced with nitrogen; delivered volume 2197 L) to the next port downstream. 
	&#8203;NOTE: Tubing must be of appropriate length to reach the gases&#39; sources comfortably. Different tanks or generators of NO can be used as sources of gas.</li>
</ol>
7. Use in spontaneously breathing subjects
<ol>
	<li>Set the air, O2, and NO gas flow according to the desired FiO2 and NO concentration. 
	NOTE: The recommended flow rates for administering NO at 80, 160, or 250 ppm are listed in Table 1 (applicable to 800 ppm cylinders only).</li>
	<li>Position the tight-fitting mask on the patient&#39;s face, similar to a non-invasive ventilation interface setup.</li>
	<li>Start the inhalation session for the desired duration.</li>
</ol>

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<li>Safaee Fakhr, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((High+concentrations+of+nitric+oxide+inhalation+therapy+in+pregnant+patients+with+severe+coronavirus+disease+2019+%28COVID-19%29%5BTitle%5D)+AND+%22Obstetrics+%26+Gynecology%22%5BJournal%5D)">High concentrations of nitric oxide inhalation therapy in pregnant patients with severe coronavirus disease 2019 (COVID-19).</a> Obstetrics & Gynecology. , (2020).</li>
<li>Gianni, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Ideation+and+assessment+of+a+nitric+oxide+delivery+system+for+spontaneously+breathing+subjects%5BTitle%5D)+AND+%22Nitric+Oxide%22%5BJournal%5D)">Ideation and assessment of a nitric oxide delivery system for spontaneously breathing subjects.</a> Nitric Oxide. 104-105, 29-35 (2020).</li>
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<li>Bhorade, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Response+to+inhaled+nitric+oxide+in+patients+with+acute+right+heart+syndrome%5BTitle%5D)+AND+%22American+Journal+of+Respiratory+and+Critical+Care+Medicine%22%5BJournal%5D)">Response to inhaled nitric oxide in patients with acute right heart syndrome.</a> American Journal of Respiratory and Critical Care Medicine. 159 (2), 571-579 (1999).</li>
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</ol>

L.B. receives salary support from K23 HL128882/NHLBI NIH as a principal investigator for his work on hemolysis and nitric oxide. L.B. receives technologies and devices from iNO Therapeutics LLC, Praxair Inc., Masimo Corp. L.B. receives a grant from iNO Therapeutics LLC. A.F. and L.T. reported funds from the German Research Foundation (DFG) F.I. 2429/1-1; TR1642/1-1. WMZ receives a grant from NHLBI B-BIC/NCAI (#U54HL119145), and he is on the scientific advisory board of Third Pole Inc., which has licensed patents on electric NO generation from MGH. All other authors have nothing to declare.

Given the increasing interest in NO gas therapy for non-intubated patients, including those with COVID-198, the present report describes a novel custom device and how to assemble its components to deliver NO at concentrations as high as 250 ppm. The proposed system is built out of inexpensive consumables and safely delivers a reproducible concentration of NO gas in spontaneously breathing patients. The ease of assembly and use, together with the safety data published elsewhere16<...

NO inhalation therapy is regularly used as a life-saving treatment in several clinical settings1,2,3. In addition to its well-known pulmonary vasodilator effect4, NO displays a broad antimicrobial effect against bacteria5, viruses6, and fungi7, particularly if administered at high concentrations (&#62;100 ppm).8 During the 2003 Severe Acute Respiratory Syndrome (SARS) outbreak, NO showed potent antiviral activity in vitro and demonstrated therapeutic efficacy in patients infected with the SARS-Coronavirus (SARS-CoV)9,10. The 2003 strain is structurally similar to SARS-Cov-2, the pathogen responsible for the current Coronavirus Disease-2019 (COVID-19) pandemic11. Three randomized controlled clinical trials are ongoing in patients with COVID-19 to determine the potential benefits of breathing high-concentration NO gas to improve outcomes12,13,14. In a fourth ongoing study, the prophylactic inhalation of high concentrations of NO is being investigated as a preventive measure against the development of COVID-19 in healthcare providers exposed to SARS-CoV-2-positive patients15.
The development of an effective and safe treatment for COVID-19 is a priority for the healthcare and scientific communities. To investigate the administration of NO gas at doses &#62; 80 ppm in non-intubated patients and volunteering healthcare workers, the need to develop a safe and reliable non-invasive system became apparent. This technique aims to administer high NO concentrations at different fractions of inspired oxygen (FiO2) to spontaneously breathing subjects. The methodology described here is currently in use for research purposes in spontaneously breathing COVID-19 patients at the Massachusetts General Hospital (MGH)16,17. Following the guidelines of MGH&#39;s human research ethics committee, the proposed system is currently in use to conduct a series of randomized controlled trials to study the following effects of high concentrations of NO gas. First, the effect of 160 ppm NO gas is being studied in non-intubated subjects with mild-moderate COVID-19, admitted either in the Emergency Department (IRB Protocol #2020P001036)14 or as inpatients (IRB Protocol #2020P000786)18. Second, the role of high-dose NO is being examined to prevent SARS-CoV-2 infection and the development of COVID-19 symptoms in healthcare providers routinely exposed to SARS-CoV-2-positive patients (IRB Protocol # 2020P000831)19.
This simple device can be assembled with standard consumables routinely used for respiratory therapy. The proposed apparatus is designed to non-invasively deliver a mixture of NO gas, medical air, and oxygen (O2). Nitrogen dioxide (NO2) inhalation is minimized to reduce the risk of airway toxicity. The current NO2 safety threshold set by the American Conference of Governmental Industrial Hygienists is 3 ppm over an 8-h time-weighted average, and 5 ppm is the short-term exposure limit. Conversely, the National Institute for Occupational Safety and Health recommends 1 ppm as a short-term limit of exposure20. Given the increasing interest in high-dose NO gas therapy, the present report provides the necessary description of this novel device. It explains how to assemble its components to deliver a high concentration of NO for research purposes.

<table><tbody><tr><td>90&amp;deg; ventilator elbow connector without ports 22 mm ID x 22 mm OD</td><td>Teleflex, Wayne, PA, USA</td><td>1641</td><td></td></tr><tr><td>Aerosol tee connector: horizontal ports 22 mm OD, vertical port 11 mm ID/22 mm OD</td><td>Teleflex, Wayne, PA, USA</td><td>1077</td><td></td></tr><tr><td>Flexible patient connector for endotracheal or tracheostomy tube (15 mm OD x 22 mm OD/15 mm ID, length 5 cm to 6.5 cm)</td><td>Vyaire Medical Inc., Mettawa, IL, USA</td><td>3215</td><td></td></tr><tr><td>High-efficiency particulate air (highly hydrophobic bacterial/viral filter,&amp;nbsp; HEPA class 13) filter (22 mm ID/15 mm OD x 22 mm OD/15 mm ID connector)</td><td>Teleflex, Wayne, PA, USA</td><td>28012</td><td></td></tr><tr><td>Latex-free 3-L breathing reservoir bag</td><td>CareFusion, Yorba Linda, CA, USA</td><td>5063NL</td><td></td></tr><tr><td>Nitric Oxide tank 800 ppm medical-grade (size AQ aluminum cylinders containing 2239 L at STP of 800 ppm NO gas balanced with nitrogen, volume 2197 L)</td><td>Praxair, Bethlehem PA, USA</td><td>MM NO800NI-AQ</td><td></td></tr><tr><td>One-way valve 22 mm male/female (arrow pointing towards female end)</td><td>Teleflex, Wayne, PA, USA</td><td>1664</td><td>N=2 inspiratory limb (upward arrow)</td></tr><tr><td>One-way valve 22 mm male/female (arrow pointing towards male end)</td><td>Teleflex, Wayne, PA, USA</td><td>1665</td><td>N=1 expiratory limb (downward arrow)</td></tr><tr><td>Rad-57 Handheld Pulse Oximeter with Rainbow SET Technology</td><td>Masimo Corporation, Irvine, CA, USA</td><td>3736</td><td>Including SpMet Option</td></tr><tr><td>Scavenger (ID = 60 mm, internal length = 53 mm, volume = 150 mL) containing 100 g of calcium hydroxide</td><td>Spherasorb, Intersurgical Ltd, Berkshire, UK</td><td></td><td></td></tr><tr><td>Silicon rubber flexible connectors 22 mm F x 22 mm F</td><td>Tri-anim Health Services, Dublin, OH, USA</td><td>301-9000</td><td></td></tr><tr><td>Snug-fit standard face mask of appropriate size</td><td></td><td></td><td></td></tr><tr><td>Star Lumen standard medical grade vynil oxygen tubing with universal connectors</td><td>Teleflex, Morrisville, NC, USA</td><td>1115</td><td>Variable length according to distance from source of gas. 2.1 m length used in protocol</td></tr><tr><td>Straight connector with a 7.6 mm sampling port (15 mm OD x 15 mm ID/22 mm OD)</td><td>Mallinckrodt, Bedminster, NJ, USA</td><td>502041</td><td></td></tr><tr><td>Two-step adapter (15 mm to 22 mm)</td><td>Airlife Auburndale, FL, USA</td><td>1824</td><td></td></tr><tr><td>Y-piece connector with 7.6 mm ports (22 mm to 22 mm and 15 F)</td><td>Vyaire Medical Inc., Mettawa, IL, USA</td><td>1831</td><td></td></tr></tbody></table>

a novel inhalation mask system to deliver high concentrations of nitric oxide gas in spontaneously breathing subjects

Nitric Oxide (NO) is administered as gas for inhalation to induce selective pulmonary vasodilation. It is a safe therapy, with few potential risks even if administered at high concentration. Inhaled NO gas is routinely used to increase systemic oxygenation in different disease conditions. The administration of high concentrations of NO also exerts a virucidal effect in vitro. Owing to its favorable pharmacodynamic and safety profiles, the familiarity in its use by critical care providers, and the potential for a direct virucidal effect, NO is clinically used in patients with coronavirus disease-2019 (COVID-19). Nevertheless, no device is currently available to easily administer inhaled NO at concentrations higher than 80 parts per million (ppm) at various inspired oxygen fractions, without the need for dedicated, heavy, and costly equipment. The development of a reliable, safe, inexpensive, lightweight, and ventilator-free solution is crucial, particularly for the early treatment of non-intubated patients outside of the intensive care unit (ICU) and in a limited-resource scenario. To overcome such a barrier, a simple system for the non-invasive NO gas administration up to 250 ppm was developed using standard consumables and a scavenging chamber. The method has been proven safe and reliable in delivering a specified NO concentration while limiting nitrogen dioxide levels. This paper aims to provide clinicians and researchers with the necessary information on how to assemble or adapt such a system for research purposes or clinical use in COVID-19 or other diseases in which NO administration might be beneficial.

A 33-year-old respiratory therapist working at the ICU at MGH during the surge of ICU admission for COVID-19 volunteered to receive NO as part of the trial involving healthcare workers15,19. The trial tested the efficacy of 160 ppm of NO as a virucidal agent, thereby preventing disease occurrence in lungs at risk for viral contamination. The first session of the inhalation prophylaxis was administered before starting a shift throu...

Watch this Scientific Journal Video about A Novel Inhalation Mask System to Deliver High Concentrations of Nitric Oxide Gas in Spontaneously Breathing Subjects at JoVE.com

A Novel Inhalation Mask System to Deliver High Concentrations of Nitric Oxide Gas in Spontaneously Breathing Subjects

This simple and highly adaptable system device for the inhalation of high-concentration nitric oxide (NO) gas does not require mechanical ventilators, positive pressure, or high gas flows. Standard medical consumables and a snug-fitting mask are used to safely deliver NO gas to spontaneously breathing subjects.

Nitric Oxide (NO) is administered as gas for inhalation to induce selective pulmonary vasodilation. It is a safe therapy, with few potential risks even if ...

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Research

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Medicine

4.7K Views.  Massachusetts General Hospital and Harvard Medical School. Ingeademd stikstofmonoxide kan de oxygenatie verbeteren bij patiënten met ernstige hypoxemie. Bij hoge concentraties vertoont stikstofmonoxide brede antimicrobiële effecten. Verschillende onderzoeken testen het effect van stikstofmonoxide op COVID-19.Tot op heden is er geen apparaat beschikbaar dat in staat is om ingeademd stikstofmonoxide toe te dienen bij concentraties hoger dan 80 delen per miljoen zonder dat er speciale zware en dure apparatuur nodig is. Met dit apparaat kan hoog...

Video: A Novel Inhalation Mask System to Deliver High Concentrations of Nitric Oxide Gas in Spontaneously Breathing Subjects

A Novel Rescue Technique for Difficult Intubation and Difficult Ventilation

We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which works especially well with poor mask fit.
Can not intubate, can not ventilate" (CICV) is a potentially life threatening situation. In this video we present a simulation of the technique we used in a case of CICV where oxygenation and ventilation were maintained by inserting an endotracheal tube (ETT) nasally down to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.
A 13 year old patient was taken to the operating room for incision and drainage of a neck abcess and direct laryngobronchoscopy. After preoxygenation, anesthesia was induced intravenously. Mask ventilation was found to be extremely difficult because of the swelling of the soft tissue. The face mask could not fit properly on the face due to significant facial swelling as well. A direct laryngoscopy was attempted with no visualization of the larynx. Oxygen saturation was difficult to maintain, with saturations falling to 80%. In order to oxygenate and ventilate the patient, an endotracheal tube was then inserted nasally after nasal spray with nasal decongestant and lubricant. The tube was pushed gently and blindly into the hypopharynx. The mouth and nose of the patient were sealed by hand and positive pressure ventilation was possible with 100% O2 with good oxygen saturation during that period of time. Once the patient was stable and well sedated, a rigid bronchoscope was introduced by the otolaryngologist showing extensive subglottic and epiglottic edema, and a mass effect from the abscess, contributing to the airway compromise. The airway was secured with an ETT tube by the otolaryngologist.This video will show a simulation of the technique on a patient undergoing general anesthesia for dental restorations.

We describe a technique to maintain oxygenation and ventilation using an endotracheal tube inserted nasally to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.

We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which ...

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department

Carbon dioxide (CO2) along with oxygen (O2) share the role of being the most important gases in the human body. The measuring of expired CO2 at the mouth has solicited growing clinical interest among physicians in the emergency department for various indications: (1) surveillance et monitoring of the intubated patient; (2) verification of the correct positioning of an endotracheal tube; (3) monitoring of a patient in cardiac arrest; (4) achieving normocapnia in intubated head trauma patients; (5) monitoring ventilation during procedural sedation. The video allows physicians to familiarize themselves with the use of capnography and the text offers a review of the theory and principals involved. In particular, the importance of CO2 for the organism, the relevance of measuring expired CO2, the differences between arterial and expired CO2, the material used in capnography with their artifacts and traps, will be reviewed. Since the main reluctance in the use of expired CO2 measurement is due to lack of correct knowledge concerning the physiopathology of CO2 by the physician, we hope that this explanation and the video sequences accompanying will help resolve this limitation.

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department

This video describes how to perform CO2 measurement in intubated as well as spontaneously breathing patients. The main clinical indications refer to emergency situations: (1) verifying adequate positioning of an endotracheal tube; (2) achieving normocapnia in trauma patients; (3) monitoring ventilation in the case of procedural sedation.

Carbon dioxide (CO2) along with oxygen (O2) share the role of being the most important gases in the human body. The measuring of expired CO2 at the mouth ...

Development of a Nose-only Inhalation Toxicity Test Chamber That Provides Four Exposure Concentrations of Nano-sized Particles

Using a numerical analysis based on computerized fluid dynamics, a nose-only inhalation toxicity chamber with four different exposure concentrations is designed and validated for flow field uniformity and cross-contamination among the exposure ports for each concentration. The designed flow field values are compared with the measured values from exposure ports located horizontally and vertically. For this purpose, nanoscale sodium chloride particles are generated as test particles and introduced to the inhalation chamber to evaluate the cross-contamination and concentration maintenance among the chambers, for each concentration group. The results indicate that the designed multiconcentration inhalation chamber can be used in animal inhalation toxicity testing without cross-contamination among concentration groups. Moreover, the designed multiconcentration inhalation toxicity chamber can also be converted to a single-concentration inhalation chamber. Further testing with gas, organic vapor, or non-nanoscale particles will ensure the use of the chamber in the inhalation testing of other test articles.

A nose-only inhalation toxicity chamber capable of testing inhalation toxicity at four different exposure concentrations was designed and validated for flow field uniformity and cross-contamination between the exposure ports for each concentration. Here, we present a protocol to confirm that the designed chamber is effective for inhalation toxicity testing.

Using a numerical analysis based on computerized fluid dynamics, a nose-only inhalation toxicity chamber with four different exposure concentrations is ...

Engineering

MRI Mapping of Cerebrovascular Reactivity via Gas Inhalation Challenges

The brain is a spatially heterogeneous and temporally dynamic organ, with different regions requiring different amount of blood supply at different time. Therefore, the ability of the blood vessels to dilate or constrict, known as Cerebral-Vascular-Reactivity (CVR), represents an important domain of vascular function. An imaging marker representing this dynamic property will provide new information of cerebral vessels under normal and diseased conditions such as stroke, dementia, atherosclerosis, small vessel diseases, brain tumor, traumatic brain injury, and multiple sclerosis. In order to perform this type of measurement in humans, it is necessary to deliver a vasoactive stimulus such as CO2 and/or O2 gas mixture while quantitative brain magnetic resonance images (MRI) are being collected. In this work, we presented a MR compatible gas-delivery system and the associated protocol that allow the delivery of special gas mixtures (e.g., O2, CO2, N2, and their combinations) while the subject is lying inside the MRI scanner. This system is relatively simple, economical, and easy to use, and the experimental protocol allows accurate mapping of CVR in both healthy volunteers and patients with neurological disorders. This approach has the potential to be used in broad clinical applications and in better understanding of brain vascular pathophysiology. In the video, we demonstrate how to set up the system inside an MRI suite and how to perform a complete experiment on a human participant.

Non-invasive imaging of the brain vasculature&#8217;s ability to dilate or constrict may allow a better understanding of cerebrovascular pathophysiology in various neurological diseases. The present report describes a reproducible and patient-comfortable protocol to perform vascular reactivity imaging in humans using magnetic resonance imaging (MRI).

The brain is a spatially heterogeneous and temporally dynamic organ, with different regions requiring different amount of blood supply at different time. ...

Modeling and Simulations of Olfactory Drug Delivery with Passive and Active Controls of Nasally Inhaled Pharmaceutical Aerosols

There are many advantages of direct nose-to-brain drug delivery in the treatment of neurological disorders. However, its application is limited by the extremely low delivery efficiency (&#60; 1%) to the olfactory mucosa that directly connects the brain. It is crucial to develop novel techniques to deliver neurological medications more effectively to the olfactory region. The objective of this study is to develop a numerical platform to simulate and improve intranasal olfactory drug delivery. A coupled image-CFD method was presented that synthetized the image-based model development, quality meshing, fluid simulation, and magnetic particle tracking. With this method, performances of three intranasal delivery protocols were numerically assessed and compared. Influences of breathing maneuvers, magnet layout, magnetic field strength, drug release position, and particle size on the olfactory dosage were also numerically studied.
From the simulations, we found that clinically significant olfactory dosage (up to 45%) were feasible using the combination of magnet layout and selective drug release. A 64 -fold higher delivery of dosage was predicted in the case with magnetophoretic guidance compared to the case without it. However, precise guidance of nasally inhaled aerosols to the olfactory region remains challenging due to the unstable nature of magnetophoresis, as well as the high sensitivity of olfactory dosage to patient-, device-, and particle-related factors.

This manuscript reviews the modeling and simulations of different protocols to deliver medications to the olfactory region in image-based nasal airway models. Multiple software modules are used to develop the anatomically accurate nose model, generate computational mesh, simulate nasal airflows, and predict particle deposition at the olfactory region.

There are many advantages of direct nose-to-brain drug delivery in the treatment of neurological disorders. However, its application is limited by the ...

Dry Powder and Nebulized Aerosol Inhalation of Pharmaceuticals Delivered to Mice Using a Nose-only Exposure System

Obstructive respiratory diseases like asthma and chronic obstructive pulmonary disease (COPD) are currently treated by inhaled anti-inflammatory and bronchodilator drugs. Despite the availability of multiple treatments, both diseases are growing public health concerns. The majority of asthma patients are well controlled on current inhaled therapies but a substantial number of patients with severe asthma are not. Asthma affects an estimated 300 million people worldwide and approximately 20 percent have a severe form of the disease. In contrast to asthma, there are few effective therapies for COPD. An estimated 10% of the population has COPD and the trend in death rates is increasing for COPD while decreasing for other major diseases. Although developing drugs for inhaled delivery is challenging, the nose-only inhalation unit enables direct delivery of novel drugs to the lung of rodents for pre-clinical efficacy and safety/toxicology studies. Inhaled drug delivery has multiple advantages for respiratory diseases, where high concentration in the lung improves efficacy and minimizes systemic side effects. Inhaled corticosteroids and bronchodilators benefit from these advantages and inhaled delivery may also hold potential for future biologic therapies. The inhalation unit described herein can generate, sample for characterization, and uniformly deposit a drug aerosol in the lungs of rodents. This enables the pre-clinical determination of the efficacy and safety of drug doses deposited in the lungs of rodents, key data required before initiating clinical development.

The inhalation unit described herein can generate, sample for characterization, and uniformly deposit a drug aerosol in the lungs of rodents. This enables the pre-clinical determination of the efficacy and safety of drug doses deposited in the lungs; key data enabling clinical inhaled drug development.

Obstructive respiratory diseases like asthma and chronic obstructive pulmonary disease (COPD) are currently treated by inhaled anti-inflammatory and ...

Novel Methods for Intranasal Administration Under Inhalation Anesthesia to Evaluate Nose-to-Brain Drug Delivery

Intranasal administration has been reported to be a potential pathway for nose-to-brain delivery of therapeutic agents that circumvents the blood-brain barrier. However, there have been few reports regarding not only the quantitative analysis but also optimal administration conditions and dosing regimens for investigations of nose-to-brain delivery. The limited progress in research on nose-to-brain pathway mechanisms using rodents represents a significant impediment in terms of designing nose-to-brain delivery systems for candidate drugs.
To gain some headway in this regard, we developed and evaluated two novel methods of stable intranasal administration under inhalation anesthesia for experimental animals. We also describe a method for the evaluation of drug distribution levels in the brain via the nose-to-brain pathway using radio-labeled [14C]-inulin (molecular weight: 5,000) as a model substrate of water-soluble macromolecules.
Initially, we developed a pipette-based intranasal administration protocol using temporarily openable masks, which enabled us to perform reliable administration to animals under stable anesthesia. Using this system, [14C]-inulin could be delivered to the brain with little experimental error.
We subsequently developed an intranasal administration protocol entailing reverse cannulation from the airway side through the esophagus, which was developed to minimize the effects of mucociliary clearance (MC). This technique led to significantly higher levels of [14C]-inulin, which was quantitatively detected in the olfactory bulb, cerebrum, and medulla oblongata, than the pipette method. This appears to be because retention of the drug solution in the nasal cavity was substantially increased by active administration using a syringe pump in a direction opposite to the MC into the nasal cavity.
In conclusion, the two methods of intranasal administration developed in this study can be expected to be extremely useful techniques for evaluating pharmacokinetics in rodents. The reverse cannulation method, in particular, could be useful for evaluating the full potential of nose-to-brain delivery of drug candidates.

Here, we describe two novel methods of stable intranasal administration under inhalation anesthesia with minimal physical stress for experimental animals. We also describe a method for quantitative evaluation of drug distribution levels in the brain via the nose-to-brain pathway using radiolabeled [14C]-inulin as a model substrate of water-soluble macromolecules.

Intranasal administration has been reported to be a potential pathway for nose-to-brain delivery of therapeutic agents that circumvents the blood-brain ...

Quantitative Mapping of Specific Ventilation in the Human Lung using Proton Magnetic Resonance Imaging and Oxygen as a Contrast Agent

Specific ventilation imaging (SVI) is a functional magnetic resonance imaging technique capable of quantifying specific ventilation &#8213; the ratio of the fresh gas entering a lung region divided by the region&#8217;s end-expiratory volume &#8213; in the human lung, using only inhaled oxygen as a contrast agent. Regional quantification of specific ventilation has the potential to help identify areas of pathologic lung function. Oxygen in solution in tissue shortens the tissue&#8217;s longitudinal relaxation time (T1), and thus a change in tissue oxygenation can be detected as a change in T1-weighted signal with an inversion recovery acquired image. Following an abrupt change between two concentrations of inspired oxygen, the rate at which lung tissue within a voxel equilibrates to a new steady-state reflects the rate at which resident gas is being replaced by inhaled gas. This rate is determined by specific ventilation. To elicit this sudden change in oxygenation, subjects alternately breathe 20-breath blocks of air (21% oxygen) and 100% oxygen while in the MRI scanner. A stepwise change in inspired oxygen fraction is achieved through use of a custom three-dimensional (3D)-printed flow bypass system with a manual switch during a short end-expiratory breath hold. To detect the corresponding change in T1, a global inversion pulse followed by a single shot fast spin echo sequence was used to acquire two-dimensional T1-weighted images in a 1.5&#160;T MRI scanner, using an eight-element torso coil. Both single slice and multi-slice imaging are possible, with slightly different imaging parameters. Quantification of specific ventilation is achieved by correlating the time-course of signal intensity for each lung voxel with a library of simulated responses to the air/oxygen stimulus. SVI estimations of specific ventilation heterogeneity have been validated against multiple breath washout and proved to accurately determine the heterogeneity of the specific ventilation distribution.

Specific ventilation imaging is a functional magnetic resonance imaging technique that allows for quantification of regional specific ventilation in the human lung, using inhaled oxygen as a contrast agent. Here, we present a protocol to collect and analyze specific ventilation imaging data.

Specific ventilation imaging (SVI) is a functional magnetic resonance imaging technique capable of quantifying specific ventilation &#8213; the ratio of ...

A Technique to Generate and Deliver Drug Aerosols Directly to Mouse Lungs

Source: Phillips, J. E. et al., <a href="https://app.jove.com/v/55454">Dry Powder and Nebulized Aerosol Inhalation of Pharmaceuticals Delivered to Mice Using a Nose-only Exposure System.</a>&#160;J. Vis. Exp. (2017)
This video demonstrates the generation of drug aerosols and the targeted nose-only delivery of these aerosols to mice using an inhalation unit equipped with an aerosol generator. The mouse is restrained in a nose-only restrainer and connected to the inhalation unit, which delivers the drug directly into the mouse&#39;s nasal cavity. Subsequently, the drug passes through the trachea and enters the lungs.

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.
1. ...

JoVE Encyclopedia of Experiments

Immunology

Immunotherapy

Model Development and Disease Study

Oxygen Delivering System I: Nasal Cannula and Face Mask

The human body requires oxygen to function, and when the natural process of respiration is hindered, external devices, including the following, are needed to help deliver this vital gas.
Nasal Cannula
A nasal cannula is a lightweight tube split at one end into two prongs and placed in the nostrils. It is typically used to deliver low to medium levels of oxygen.
Suggested flow rate: The suggested flow rate for a nasal cannula typically ranges between 1 and 6 L/min.
Oxygen percentage setting: This device can deliver an oxygen concentration of about 24% - 44%, depending on the patient&#39;s breathing rate and flow setting.
Advantages: Nasal cannulas offer comfort and convenience, enabling patients to eat, drink, and communicate effortlessly. Additionally, they promote mobility and flexibility, enhancing the overall patient experience.
Disadvantages: Nasal cannulas may cause dryness or irritation in the nasal passages, and high flow rates may not provide sufficient oxygen for some patients.
Nursing responsibilities: Nurses should monitor the patient&#39;s oxygen saturation, ensure proper fit, and frequently assess the patient&#39;s nostrils for signs of irritation or infection.
O2 Conserving Cannula
An O2-conserving cannula, also known as an Oxymizer, is a device that conserves oxygen by capturing the exhaled gas in a reservoir to be inhaled with the next breath.
Suggested flow rate: The flow rate for an O2-conserving cannula is usually around 0.5-5 L/min.
Oxygen percentage setting: The oxygen concentration varies but can deliver up to 30-50% more oxygen than a standard nasal cannula.
Advantages: The main advantage of an O2-conserving cannula is that it delivers a higher oxygen concentration, reducing the oxygen supply usage.
Disadvantages: They are more expensive than standard nasal cannulas and may be less comfortable due to their larger size.
Nursing responsibilities: Nurses should monitor oxygen saturation, ensure the device functions properly, and educate patients about the device&#39;s benefits and proper use.
Partial rebreather mask
A partial rebreather mask is a face mask with an attached reservoir bag. It allows the patient to rebreathe about one-third of the exhaled air and oxygen supply.
Suggested flow rate: The flow rate for a partial rebreather mask is typically 6-10 L/min.
Oxygen percentage setting: This mask can deliver an oxygen concentration of approximately 60% - 75%.
Advantages: It provides a higher concentration of oxygen than nasal cannulas.
Disadvantages: It can be uncomfortable and restricts eating, drinking, and communication. The fit must be correct to prevent room air dilution.
Nursing responsibilities: Nurses should monitor oxygen levels, ensure the mask fits properly, and check that the reservoir bag inflates slightly upon exhalation and deflates with each inhalation.
Simple Face Mask
A simple face mask covers the nose and mouth and delivers a high oxygen concentration.
Suggested flow rate: The suggested flow rate for a simple face mask is usually between 5 and 10 L/min.
Oxygen percentage setting: This mask can deliver approximately 40% - 60% oxygen concentration.
Advantages: It can provide a higher oxygen concentration than a nasal cannula.
Disadvantages: It may be uncomfortable and interfere with eating, drinking, and communication. It also requires a tight seal to function effectively.
Nursing responsibilities: Nurses should monitor the patient&#39;s oxygen saturation, ensure the mask fits properly, and check for signs of skin irritation or pressure sores.

The human body requires oxygen to function, and when the natural process of respiration is hindered, external devices, including the following, are needed ...

A Novel Inhalation Mask System to Deliver High Concentrations of Nitric Oxide Gas in Spontaneously Breathing Subjects

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