The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts

MEASUREMENT OF OXYGEN (PO2) IN HUMAN BLOOD FOLLOWING INFUSION OF DILUTE HYDROGEN PEROXIDE

Matthew J. O'Brien1, Thomas G. Steffens2



Background: Raising patients' PaO2 is a critical endeavor- options are limited to increasing inspired oxygen concentrations, increasing gas pressure or extracorpeal membrane oxygenation (ECMO). Hydrogen Peroxide (H2O2) reacts with catalase in blood; this reaction yields water and oxygen. Investigation using various concentrations of hydrogen peroxide infused directly into the circulatory system has been performed; however accurate assessments of change in PO2-using inline monitoring has not.

Will infused dilutions of H2O2 result in a measurable increase in PO2 when measured with an inline monitor-using an ECMO circuit containing red blood cells (RBCs)? What is the lowest concentration that yields an effective increase in blood PO2?

Methods:
An ECMO circuit and calibrated Terumo CVS CDI 500™ blood parameter monitoring system was used to monitor PO2 following infusion of various concentrations of H2O2 into RBCs. Statistical analysis: Correlation coefficient of ABG result and inline monitor.
Trial 1: Approximately 200 mL of RBCs circulating at 300 mL/min; PO2 was equilibrated; sample was sent to lab for PO2 analysis. The blood gas result was used to reference the inline blood monitoring system (CDI). The oxgenator was isolated to prevent any further ventilation during the trial. A slow injection of .09% H2O2 (15 mL) was added to the circuit bladder over 2 minutes.
Trial 2: A controlled infusion of .01, .02 and .04 % concentrations of H2O2 into the ECMO circuit with the same conditions as Trial 1. Infusion rate was 20 mL/hr and circulated for approximately 80 minutes.

Results:
Trial 1: Slow injection
.09 % PO2 increased from 123 mm Hg to over 700 mmHg within 3 minutes.
Trial 2:
Infusion:20 mL/hr
.01%: PO2 increased from 96 to 183 mmHg in 86 minutes
.02%: PO2 increased from 102 to 212 mmHg over 89 minutes
.04%: PO2 increased from 104 to 400 mmHg over 88 minutes
PO2 increases in a linear fashion and there is a positive correlation coefficient of 1 between the CDI monitor and ABG specimen results.

Conclusion:
PO2 increased following infusion of dilute concentrations of H2O2. Concentrations as low as .01% yields and effective increase in PO2 when infused at 20 ml/hr. An ECMO system with a inline blood gas monitor is a reliable model for future testing of reactive oxygenation. Reactive oxygenation may be an effective method to increase PO2 when other therapies are unavailable or prove ineffective.