A Descriptive Study of the Percentage of Oxygen Delivered Using the Mercury Tube-Valve-Mask Breathing Circuit at 2 L/min Flow Rates
Abstract
The purpose of this study was to determine the efficacy of the Mercury tube-valve-mask oxygen delivery system at 2 L/min, 3 L/min and 4 L/min flows using an oxygen concentrator (Oxygen 93 % USP) and Oxygen 99% USP. A descriptive design was used. Eighteen healthy volunteers (ages 28-43) were recruited from the students and faculty at the Army Medical Department Center and School in San Antonio, Texas. The trials consisted of the subject breathing through the Mercury tube-valve-mask breathing circuit at 2 L/min, 3 L/min and 4 L/min flow rates using an oxygen concentrator (Oxygen 93 % USP) and Oxygen 99% USP. Each subject was randomly assigned to order of oxygen source and flow rate, received all 6 trials, and served as their own control. The subject breathed from the oxygen source and flow rate selected until a sustained fraction inspired oxygen concentration%(FiO2) was determined. Once the sustained FiO2 was determined and there was less than 10% variation in FiO2, a three-minute trial began. Data collection consisted of the subjects FiO2, respiratory rate, tidal volume and minute volume. It was hypothesized that the Mercury tube-valve-mask breathing circuit would deliver a FiO2 of 0.40, 0.50, and 0.60 at flow rates of 2 L/min, 3 L/min, and 4 L/min, respectively. A chi-square goodness-of-fit test was used to determine if 85% of the subjects achieved the desired FiO2 at the predetermined flow rate. The 85% criterion was not reached in any of the conditions tested. The mean FiO2 at 2 L/min was 0.35 with Oxygen 93% USP and 0.36 with Oxygen 99% USP. The mean FiO2 at 3 L/min was 0.45 with Oxygen 93% USP and 0.45 with Oxygen 99% USP. The mean FiO2 at 4 L/min was 0.52 with Oxygen 93% USP and 0.53 with Oxygen 99% USP. Although the predicted values of FiO2 were not met, it was found that the Mercury tube-valve-mask breathing circuit was capable of delivering higher concentrations of oxygen than traditional oxygen delivery systems.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2002
- Accession Number
- ADA426750
Entities
People
- Aaron F. Holloway
- Brent E. Mitchell
- Larry A. Todd
- Raymond Baker
- Stephanie M. Gardner
Organizations
- University of Texas Health Science Center at Houston