The Science Journal of the American Association for Respiratory Care

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 Pearson’s 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.