2012 OPEN FORUM Abstracts
SHELF LIFE AND GAS CONCENTRATION STABILITY OF SUPERSATURATED DISSOLVED OXYGEN SOLUTIONS AT REDUCED TEMPERATURE.
Daniel J. Grady1, Michael A. Gentile2, John H. Riggs3, Terrence F. Smith1, Todd McCarl1, Ira M. Cheifetz2, Gregg Stashenko1; 1Respiratory Care, Mission Health System, Asheville, NC; 2Pediatric Critical Care Medicine, Duke Health System, Durham, NC; 3Clinical Research, VentLab Inc, Mocksville, NC
Background: Although dissolved oxygen has been considered insignificant when compared to hemoglobin during blood oxygen transport, hyperbaric medicine studies have shown that dissolved oxygen alone may sustain life in the absence of hemoglobin when hyperbaric levels of dissolved oxygen exist in plasma 1. Supersaturation and hyperbaric levels of dissolved oxygen in fluid may be achieved by (1) increasing the partial pressure of gas exposed to the fluid, (2) increasing the solubility of the fluid for gas solvation by decreasing fluid temperature, and (3) varying combinations of increased pressure and decreased fluid temperature. The objective of this study was to determine the length of time that hyperbaric tensions of dissolved oxygen are maintained in fluid following supersaturation. Methods: A supersaturated dissolved oxygen solution was prepared by bubbling 100% gaseous oxygen at 3 L/min through 2.5 liters of sterile water for 20 minutes at a temperature of 43 degrees F = 6 C. Ambient oxygen percentage was controlled by means of a gas blender/ flowmeter. After 20 minutes of bubbling oxygen gas in the liquid, the oxygen flowmeter was turned off. The temperature of the sterile water solution remained constant at 43 degrees F and was regulated by circulation of ice water refrigerant via coiled tubing within the experimental solution using a novel hyperbaric tonometer. Solution temperature and the dissolved oxygen concentration (mg/L) were measured at 15 minute intervals. A total of 22 measurements were made. Dissolved O2 concentration in solution (mg/L) was measured by a Hanna Instruments HI 98186 dissolved oxygen analyzer. Measurements were made under conditions of ATPS. Results: Following supersaturation of the liquid at 55 degrees F, the dissolved oxygen concentration remained stabel at 50 mg/L (the upper limit of the analyzer) for more than 4 hours as shown in the graph. Conclusions: This study demonstrates that a supersaturated dissolved oxygen solution, contains greater than atmospheric partial pressures of dissolved oxygen, remains stable, and retains high dissolved oxygen concentrations for extended time periods. Although gaseous oxygen bubbled through water appears to the naked eye to bubble out of solution, liquid water retains extremely high dissolved oxygen partial pressures in a stable solution, when the temperature of the solution is decreased and maintained as a cold solution. Sponsored Research - None 1. Bassett BE and Bennett PB. Introduction to the Physical and Physiological Bases of Hyperbaric Therapy. Hyperbaric Oxygen Therapy. Undersea and Hyperbaric Medical Society, Bethesda, MD1988, p. 15.