EVALUATION OF THE USE OF 3 DIFFERENT DEVICES FOR NOCTURNAL OXYGEN-THERAPY IN COPD PATIENTS

Objective: To determine whether transtracheal catheter and reservoir n asal cannula contribute to maintaining adequate oxygen saturation duri ng sleep, and to calculate the oxygen saving they allow compared to na sal prongs. Design: A prospective study in which patients were randoml y assigned to either nasal prongs or oxymizer device prior to transtra cheal oxygen delivery. Arterial oxygen saturation was then monitored b y a finger pulse oximeter during 8 h of sleep. Setting: Pulmonary ward of 'The Hospital Universitari Germans Trias i Pujol, Badalona (Barcel ona/Spain)'. Patients: Fourteen stable hypoxemic (PaO2 50 +/- 6.9 mm H g; PaCO2 51.5 +/- 9.3 mm Hg) COPD patients (FVC 44 +/- 19%; FEV(1) 26. 5 +/- 11.5%; FEV(1)/FVC 44.9 +/- 9.7%) already receiving oxygen therap y at home. Measurements: Pulmonary function test was performed. The lo west flow required to obtain an SaO(2) at or above 88% for over 95% of the sleep time was determined for each type of oxygen delivery. Patie nts were not switched to the next type of oxygen delivery device until 3 reliable pulse oximetries had been obtained. The percentage of oxyg en saving was calculated. Awake PaO2 was measured in patients using na sal prongs and transtracheal catheter while continuing to inspire oxyg en at the same flow rate as when asleep, Results: As expected, no diff erences were found in SaO(2) measurements for the three types of oxyge n delivery. Oxygen savings were 48.65% for the oxymizer device and 52. 87% for the transtracheal catheter. Awake PaO2 was significantly highe r (p < 0.04) in patients with nasal prongs than in those with transtra cheal catheter at the flow rate required when asleep. Conclusions: The oxymizer device and transtracheal oxygen delivery benefit hypoxemic C OPD patients reducing oxygen use during sleep by around 50%. Higher Pa O2 levels were necessary to prevent nocturnal SaO(2) decreases in pati ents with nasal prongs than in patients with transtracheal oxygen deli very. Oxygen-conserving devices are reliable and advisable methods for nocturnal oxygenation.