Intravenous Oxygen Administration by In Situ Nanospraying
Abstract
Oxygen is a nutrient that is continuously supplied to every cell in the body for energy production. This supply is continuously replenished, and if it is interrupted for more than a few seconds, permanent injury to the brain, heart, and other organs can result. There are several ways in which the body s oxygen supply can be interrupted. On the battlefield, for example, face or neck trauma can block a Warfighter s airway, and inhalation injuries can create acute lung injury. Medical patients may suffer from acute asthma, anaphylaxis, pneumothorax, emphysema, or lung injury from any of a long list of etiologies. Whether on the battlefield or in a critically ill patient, acute oxygen deprivation is immediately life-threatening. Such patients are treated with concentrated oxygen, opening of the airways (e.g., placement of a breathing tube), and the use of a ventilator. Each of these interventions requires expertise and specialized equipment, and most importantly, time to implement. For example, on the battlefield, support of an oxygen-deprived patient may require placement of a breathing tube (overcoming gunfire, poor lighting, patient positioning, or facial trauma, for example), supplemental oxygen administration (requiring a compressed oxygen source), and mechanical ventilation (requiring a device), all taking place during a critical evacuation period. When such interventions are delayed, Warfighters may suffer irreversible brain injury or death. Here, we are developing a new method of supporting patients with severe oxygen deprivation through the direct injection of oxygen gas into the bloodstream using a process known as nanospraying. By using a specialized needle and a very specific gas pressure, we will create droplets of oxygen gas that are ~200 nm in diameter -- about 50 times smaller than a red blood cell. These so-called nanobubbles have very unique and important properties that make the success of this approach possible. Most importantly, they have a very low surface tension, which makes it exceedingly unlikely that they will merge with other nanobubbles and create larger ones. This also makes them quite stable and unlikely to rupture, a process that is known to cause damage to the surface of red blood cells. This project will therefore establish the feasibility and technical details of such an approach, and if successful, will lead to advanced device development and large animal testing. In Aim 1 of this grant, we will establish the parameters of the needle tip, angle of insertion, and gas pressure head that optimizes the generation of nanobubbles in human plasma under flow conditions. We will utilize a microchip simulation of this process in order to optimize the efficiency of our efforts, as this process permits us to simulate a broad range of needle tips and angles of insertion with precision and ease. In Aim 2, we will test the capacity of this technique to provide a clinically relevant amount of oxygen to whole human blood in an experiment intended to replicate the factors present in the bloodstream (including pressure, flow, temperature, blood volume, and red blood cell concentration). As it would in a patient, blood will flow through tubing that passes through a pulsatile pump, elastic tubing (like arteries), a membrane gas exchanger (which removes oxygen like the tissues), and a venous system (i.e., tubing) into which oxygen will be nanosprayed using the optimized parameters from Aim 1. In this construct, we will measure the rate at which oxygen is administered to the bloodstream, the rate at which it is taken up by hemoglobin, and the total volume of oxygen we can deliver using this technique. If this experiment is ultimately successful, we will have administered the full amount of oxygen that an adult consumes (200 mL/minute) to the circuit for 6 hours with no signs of adverse effects on the blood. We believe that this project aligns with several Peer Reviewed Medical Research Progra
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 07, 2017
- Source ID
- W81XWH1710120
Entities
People
- Brian D Polizzotti
Organizations
- United States Army