The Science Journal of the American Association for Respiratory Care

2006 OPEN FORUM Abstracts

EVALUATION OF OXYGEN BLEED-IN LOCATION DURING CPAP WHEN USING AN ELECTRONIC BREATHING SIMULATOR

Ty Barnett, Eric Peart, Lutana Haan RRT. Boise State University , Boise , ID.

Background: Home-use CPAP machines deliver set pressures, entraining room air at 21% O2. If supplemental O2 is needed to maintain O2 saturation, it can be bled into the circuit through built-in ports at the mask, or into a t-piece close to the machine. The effect of bleed-in location was evaluated with two different masks, at four different O2 liter flowrates and four different levels of CPAP.

Method: A ResMed VPAP III was interfaced with a standard 6 foot circuit to a mask placed on a mannequin that was attached to the Hans Rudolph Electronic Breathing Simulator (HR 1101). The HR 1101 settings: resistance 5 cm H2O/L/sec; compliance 40 mL/cm H2O; respiratory rate 15 breaths per minute. ResMed settings: CPAP 5, 10, 15 and 20 cm H2O. Oxygen flowrates: 1, 3, 6 and 8 LPM. Masks used: ResMed Ultra Mirage FF and Respironics Comfort Full.

Results: At oxygen flowrates of 1, 3, 6 and 8 LPM, the O2 percentage was as follows: the ResMed Ultra Mirage FF, at 5 cm H2O with O2 bled in at the mask was 22, 23.5, 26 and 27%, and at the machine was 22, 24, 27 and 29%; at 10 cm H2O with O2 bled in at the mask was 22, 22.5, 24.5 and 26%, and at the machine was 22, 23, 25.5 and 27%; at 15 cm H2O with O2 bled in at the mask was 22, 23, 24 and 25%, and at the machine was 22, 23, 25 and 26%; at 20 cm H2O with O2 bled in at the mask was 22, 23, 24.5 and 25.5%, and at the machine was 22, 23, 24.5 and 25.5%; the Respironics Comfort Full 2 at 5 cm H2O with O2 bled in at the mask was 21.8, 22.8, 24.8 and 25.5%, and at the machine was 22, 23, 25 and 26.5%; at 10 cm H2O with O2 bled in at the mask was 22, 22.5, 23.5 and 24.5%, and at the machine was 22, 22.8, 24 and 25%; at 15 cm H2O with O2 bled in at the mask was 22, 23, 24 and 25%, and at the machine was 22, 23, 24 and 25%; at 20 cm H2O with O2 bled in at the mask was 22, 23, 24 and 25%, and at the machine was 22, 23, 24.8 and 25.5%.



Conclusion: Bleed-in location does affect the delivered O2. Oxygen flowrates, mask selection and pressure levels also affect the delivered O2. Oxygen should be monitored carefully when CPAP is applied to patients with different interfaces.

You are here: RCJournal.com » Past OPEN FORUM Abstracts » 2006 Abstracts » EVALUATION OF OXYGEN BLEED-IN LOCATION DURING CPAP WHEN USING AN ELECTRONIC BREATHING SIMULATOR