2012 OPEN FORUM Abstracts
CORRELATIONS BETWEEN CHANGES IN AMBIENT OXYGEN PERCENTAGE AND DISSOLVED OXYGEN CONCENTRATION DURING SOLVATION AND SOLUTION SUPERSATURATION USING A NOVEL HYPERBARIC TONOMETER.
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 University Health System, Durham, NC; 3Clinical Research, VentLab, Inc, Mocksville, NC
Background: Previous research has demonstrated that supersaturated dissolved oxygen solutions (which contain dissolved partial pressures of oxygen greater than 760 mm Hg) may be achieved outside of a hyperbaric chamber 1. The purpose of this study was to evaluate effects of various ambient oxygen concentrations on dissolved oxygen tensions in solution using 2 different solution temperatures in a novel hyperbaric tonometer. . Methods: Supersaturated dissolved oxygen solutions were prepared by bubbling gaseous oxygen at 3 L/min through 2.5 liters of sterile water for 20 minutes. Ambient oxygen percentage was selected and controlled by means of a gas blender. A total of 10 measurements of dissolved oxygen were made at 8 ambient oxygen percentages, for a total of 80 measurements per solution. The dissolved oxygen measurements were made using 2 different solution temperatures; 70 F = 22 C and; 55 F = 13 C for an overall total of 160 measurements. Dissolved O2 in solution was measured under conditions of ATPS by a Hanna Instruments HI 98186 dissolved oxygen analyzer in units of mg/L. Descriptive statistics (alpha = 0.05) and Pearsons correlation coefficient (R2) were calculated for each of the above experimental groups. Results: At both solution temperatures of 70 F and 55 F, strong correlations exist between changes in ambient oxygen percentage and subsequent dissolved oxygen concentrations in solution, with R2 = 0.995 and R2 = 0.9896; respectively. In addition, when the two solution were compared for dissolved oxygen following exposure to 100 % oxygen, statistically significant differences in concentrations of dissolved oxygen were achieved at the colder solution temperature of 55 F, p < 0.001. Conclusions: This study has demonstrated strong correlations between ambient oxygen percentages and the resulting concentration of dissolved oxygen in sterile water solutions when gas solvation occurs at different temperatures using a novel hyperbaric tonometer. Additional research is necessary to determine correlations between ambient oxygen percentage and dissolved oxygen content in electrolyte and colloidal solutions. Sponsored Research - None 1. Grady D, Smith T, and Gentile M. Measurement of Dissolved Oxygen Tension in Fluid Following Supersaturation with Oxygen Gas Using a Novel Hyperbaric Tonometer. Respir Care, Oct 2011, 56;10, pp. 1661.