Reducing oxygen waste
The comfort mode also dramatically reduces the waste and ineffective use of oxygen. It is obvious that during exhalation, there is no exchange of the additional oxygen (when delivered in a continuous mode) with the blood of the patient, so all additional oxygen delivered during this part of the respiration cycle is wasted.
On top of that, a lot of flowmeters are left open when patients leave the room for examinations performed in other hospital wards, to perform exercises in therapy rooms, when they go to the bathroom, etc. As the comfort mode reacts to the breathing of the patient, no oxygen is being spilled in between therapy sessions.
Because of the savings in oxygen and the improved therapeutic effect on patients, the O2COMFORT™ flowmeter (having an expected life-span of at least 8 years) typically earns itself back in 3 to 4 years.
Quantification of oxygen consumption
To quantify the waste reduction, Oxypoint ran several studies.
We logged the total ward oxygen consumption during 4 months using a dedicated measurement device in the cardiac surgery unit of the Antwerp University hospital. Classic oxygen flowmeters (with only continuous flow option) were rotated every week with the Oxypoint O2COMFORT flowmeter (with both continuous and comfort mode settings).
As can be seen, the flow is expressed as a block wave with low consumption during the Oxypoint weeks and high consumption during the classic weeks. In total a reduction in oxygen consumption of 75% was noted between the Oxypoint weeks and the classic weeks, both with the same oxygen saturation levels.
Oxygen savings percentage depends on the hospital department
We also did an oxygen consumption analysis at the respiratory care department of Ghent University Hospital.
The setup of the study was similar to the cardiac surgery ward, only here the flowmeters were changed every two weeks for 3 months. The sample period in this study was heavily populated with COPD patients. These patients are typically more shallow- or mouth-breathers and this pathology poses a challenge to oxygen administering systems that rely on negative breathing pressures being generated through nasal cannulas.
Therefore, the use of the continuous flow mode was more prevalent over the course of this study than during the cardiac surgery ward. Nevertheless, the totalization of the logging events resulted in a 40% reduction of oxygen consumption.