[The study of oxygen-conserving nasal cannula and evaluation of it's oxygen saving ratio in treatment].
OBJECTIVE
To study the oxygen-conserving nasal cannula(CNC), and to evaluate it's oxygen saving benefit ratio in COPD patients.


METHODS
(1) CNC was designed as a device which conserved oxygen during exhalation and given oxygen during inhalation; (2) Evaluation of the effect of oxygen therapy: blood analysis was measured at different flows of oxygen (0.5, 1.0, 1.5, 2.0 L/min) before and after oxygen therapy. The test is randomized; Oxygen saturation(SPO2) was measured at 1, 2, 3, 5, 10, 15, 30, 60, 120 minutes by pulse oximeter; (3) Evaluation of the oxygen saving benefit ratio: SPO2 was measured at 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 L/min using CNC, the standard nasal cannula (SCN) and the new CNC.


RESULTS
(1) During two hours of oxygen therapy, the values of PaO2 and SaO2 in the CNC group were always higher than those in the SNC group (P < 0.05); (2) When the supply flow to CNC was set at 0.5 L/min, 1.0 L/min, 1.5 L/min, 2.0 L/min seperately, the oxygen saving benefit ratio of CNC to SNC was 2.6:1, 1.8:1, 1.8:1 and 1.5:1 respectively. (3) The oxygen saving benefit ratio was comparable between CNC made in China and that made in foreign country.


CONCLUSIONS
It was confirmed that CNC saved oxygen at different flows of oxygen, and the oxygen saving benefit ratio was higher at lower flows than that at higher flows.
Yu
H
H
Department of Respiratory Diseases, China-Japan Friendship Hospital, Beijing 100029.
Lin
J
J
Zeng
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002404:Catheterization / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism / Q000627:therapeutic use*; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000378:metabolism
D010100:Oxygen