Savings obtained using an oxygen economizer device: a cost-minimization analysis.

As liquid oxygen represents a relevant burden on healthcare systems, different methods have been developed to reduce oxygen consumption, including economizers. The aims of the study were: 1) to evaluate the efficacy of an economizer device (Companion 5 Oxygen Saver) in a significant sample of patients, and 2) to perform cost-minimization analysis of the possible savings to be obtained using the device. The study was designed as an open, prospective clinical trial in which equivalence in haemoglobin saturation with and without the economizer device was demonstrated, preliminary to cost-minimization analysis in patients affected by restrictive and obstructive lung disease. Patients were to use their usual O2 flow, provided it was able to guarantee a saturation of > or = 90% and an arterial oxygen tension (Pa,O2) of > or = 8.0 kPa (60 mmHg) during rest, sleep and exercise with and without the economizer (mean value and different saturation ranges compared by means of parametric or nonparametric tests where appropriate). The average unit cost was calculated with and without the economizer, based on the average unit O2 consumption, and cost-minimization analysis was performed. In 29 patients enrolled, the mean (+/- SD) O2 flow in L.min-1 was 1.5 +/- 0.6 during sleep, 1.4 +/- 0.6 during rest and 2.3 +/- 1.1 during exercise. The mean oxygen saturation during sleep was 91.2 +/- 19.5% without and 97.2 +/- 3.9% with the economizer device (p = 0.09), the mean saturation during rest was 88.8 +/- 22.7% without and 92.1 +/- 14.9% with the economizer device (p = 0.42), and the mean saturation during exercise was 84.7 +/- 19.3% without and 91.8 +/- 15.9% with the economizer device (p = 0.04). The total daily O2 consumption was significantly lower using the economizer device (2,384 +/- 950.3 versus 93.0 +/- 482.9 L, p < 0.001). The potential savings, estimated per patient per year, were 530,114 +/- 184,233 L, corresponding to US$2,492 +/- 866. During the first year the total unit savings would be US$1,892. The savings, consistently relevant alongside the whole range of variation explored by sensitivity analysis both during the first and the following years, justify considering the adoption of similar economizers on a larger scale, although further studies should be performed to evaluate whether or not liquid oxygen really represents the most cost-effective method of treating hypoxaemic patients.