Purpose: Prospective study of compliance and performance with De Vilbiss concentrator (De Vo/44), in patients with COLD and domiciliary O2 therapy.
Methods: 54/136 severe COLD patients who used de Vo/44 concentrator were followed-up for 1 year, with home interviews every 2 months. Physiological measurements: FVC, FEV1, PF, Hemoglobin, ECG, blood gas tension(breathing air), smoking habits, drug therapy, and De Vo/44 performance(machine failure, flow rate and oxygen concentration accuracy).
Results: During the 1 year study 9 patients (16.6%) died and 16 (29.6%) refused the concentrator. 18 devices needed to be changed due to machine failure. Flow rates measured at De Vo/44 were 58.15 +/- 12.9 l/hour vs a theorical of 56.60 +/- 15.4 l/hour, and the purity of O2 was 94.19 +/- 0.3%. The power consumption was 1.9 +/- 0.01/ampers/hour.
Conclusion: Almost 1/3 of COLD patients refused O2 concentrators due to excessive noise, and 1/3 of the machines needed to be replaced due to malfunction. Thus level of noise and proper functioning of concentrator are two important factors, affecting compliance and performance of these machines.