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Research Spotlight: Nalini Vadivelu, MBBS,DNB, MD

October 13, 2021



Airguard, LLC is collaborating with Yale University to develop aproduct that aims to decrease lung infections caused byaspiration, one of the multifactorial contributors that lead to themore deadly nosocomial pneumonia.


In the US, there are 3 million cases of nosocomial pneumonia inpatients, annually. In such patients and in other clinicalconditions such as nutrition supplementation, neuromusculardisorders resulting in dysphagia, critical illness and in theoperating room (67 million), nasogastric tube insertions can betreatment interventions. These tubes allow gastricdecompression, but their presence may contribute to mildpulmonary infection or cause more severe nosocomialpneumonias by the aspiration of contaminated ascending gastriccontents, or of collected secretions. Existing CDC guidelines tomitigate nosocomial pneumonia, include decreased airwaymanipulation, improved oral hygiene and subglottic suction.Despite these SOPs, policies and guidelines, nosocomialpneumonias continue to be an issue, as mortality is high as 70%with the estimated annual cost to healthcare being 1.2 billionUSD.


With reference to the CDC recommendation that subglotticsuction be used as a treatment option to decrease the chances ofventilator associated pneumonia, our collaborators at Yale arecurrently clinically testing an endotracheal tube which has asubglottic suction feature. The proposed device is an alternativefor patients who are neither intubated nor ventilated, providingsuction at the hypopharyngeal level. This will decrease airwaymanipulation, reducing the potential for aerosolization, allowingclearance of secretions during the application of continuous, low-pressure suction.

Products currently in the market do not have this dual capabilityof gastric and hypopharyngeal suction ports. Our product isprotected by patents in the US, China, Hong Kong, Australia,Europe, and India.


Collaborate with Sage Product Development to optimize thedesign of the prototype , manufacture the prototype. Once 200pieces are made available , they will be used to demonstrate thatthe hypopharyngeal port meets suction requirements. Theprototype will be tested with liquids that are simulatedphysiological fluids, such as milk and blood. Liquids with threedifferent densities (0.8, 1.0, 1.2 gram per cm3) and threeviscosities ( 2, 3, 4 centipoise (cP) will be tested. Each liquidtype, a volume of 2000ml, will be suctioned via thehypopharyngeal port, using 5 different pressure settings, namely-20, -40, -60, -80, -100mm of Hg.The metrics of success of thisaim will be the demonstration that at least 80% (1600ml) issuctioned at each pressure and will reach the maximum pressurewithout collapse (lumen occlusion).


Confirm that the hypopharyngeal port meets durability andfunctionality requirements for long-term use. Thehypopharyngeal portion will be soaked for three weeks, in pHsolutions of 3.5, 5.5 and 7.5 and will be retested with the liquidsmentioned and repeating the testing procedures after soakingthe pieces. The metric of success in this aim is that the port isable to suction 80% (1600ml) of the volume, reaching a suctionpressure of 100mm of Hg, without collapse. Airguard commits toprototype revisions of material used as well as lumen size inorder to meet the specific aims. Completing the specific aims willensure that the hypopharyngeal port meets the functionality anddurability requirements.

In Phase 2, Airguard will conduct in vivo animal studies in asimulated pig model. Following animal studies, we will test thefunctionality of the device with clinical studies in humanpatients in operating rooms and in hospitalized patients. Aftercompletion of human studies, we will apply for 510(k) approvalwith a partnering company. Airguard will market its product inpartnership with a distributor company.


The nasogastric tube market is worth $1.82 billion, as the utilityvalue of nasogastric tubes is of public health relevance and goesbeyond hospitals to long term care facilities, such as nursinghomes, as well as home healthcare. By addressing a contributingfactor of nosocomial pneumonia, Airguard aims to provide valueand resulting in the reduction of mortality rates, decrease in thelength of hospitalization as well as the costs that are associatedwith the condition.


What are your research interests?

My research interest for the last 20 has been predominantly in the field of Ambulatory Pain Medicine.Practicing Anesthesiology, I developed an interest in researching

laryngeal masks and nasogastric tubes.

What motivates your interests in this topic?

There is an increased need for pain control in patients undergoing procedures in the outpatient setting. Myresearch interest in ambulatory pain has been motivated by seeing the need to follow cases in theperioperative period in patients with substance abuse, chronic pain on pain medications and patients withadvanced malignancies with associated pain undergoing outpatient procedures. It is important to preventwithdrawal in such patients and ensure optimum pain control and patient satisfaction.

My interest in laryngeal masks started with the development of a laryngeal mask with the availability of aninbuilt suction deep on the dorsal portion. Thousands of patients have used it safely. The last clinical trialon Pubmed is listed below:

Kapoor D, Singh J, Mitra S, Viswanath O, Kaye AD, Urits I, Orhurhu V. Gnana Laryngeal Airway in ClinicalPractice: A Prospective Observational Study. Turk J Anaesthesiol Reanim. 2020;48(4):280-287.

Another study on the invented laryngeal mask, Gnana laryngeal Airway4 (GLA) has recently been approvedby the IRB in Shreveport LA.

My research interest in nasogastric tubes is to provide inbuilt suction at thelevel of the hypopharyngeal suction to capture the secretions outside the naso/orogastric tube to keep theglottic area clean.

What advice would you give a junior faculty member who plans to pursue research?

It is important to find a topic of interest which one would like to conduct research which, when pursued,would also help humanity.

What is most satisfying to you personally?


most satisfying aspect of my research is to see it benefiting patients and becoming

more meaningful tothe health care personnel providing the care.

Submitted by Garrett Sendlewski on October 14, 2021