Garrod R, Bestall J C, Paul E, Wedzicha J A
Academic Department of Respiratory Medicine, St Bartholomew's, London Chest Hospital, UK.
Thorax. 1999 Mar;54(3):242-4. doi: 10.1136/thx.54.3.242.
Oxygen conserving devices may lead to substantial increases in the duration of oxygen provided. A study was undertaken to compare the performance of a pulsed dose oxygen delivery (PDOD) system with continuous flow oxygen or air during a maximal walking test.
Fourteen patients with chronic obstructive pulmonary disease (COPD) and arterial oxygen desaturation on exercise (mean (SD) forced expiratory volume in one second (FEV1) 0.83 (0.28) 1, arterial oxygen pressure (PaO2) 8.38 (1.24) kPa, arterial carbon dioxide pressure (PaCO2) 5.95 (0.86) kPa) were randomised to perform a walking test using air administered via a cylinder or continuous flow oxygen at 2 l/min or by a PDOD system.
There was no significant difference in the mean arterial oxygen saturation (SaO2) using the PDOD system or with continuous flow oxygen (p = 0.33). Patients showed greatest desaturation whilst walking with the air cylinder (SaO2 79.2 (8.59)%) which was significantly different from the desaturation with both continuous flow oxygen (87.6 (5.85)%, p = 0.001) and PDOD (85.6 (7.36)%, p = 0.004). There was no significant difference between the distance walked using oxygen delivered at 2 l/min by continuous flow or via the PDOD (p = 0.72; CI 0.34 to 1.08). The mean (SD) distance walked on continuous flow oxygen (203.6 (106.1) m) and PDOD (207.9 (109.8) m) was significantly greater than the distance walked with the air cylinder (188.6 (110.02) m); (1.12 fold increase in distance, CI 1.01 to 1.23, p = 0.02, and 1.14 fold increase in distance, CI 1.01 to 1.28, p = 0.03, respectively).
These findings suggest that the pulsed dose oxygen conserving device was as effective as continuous flow oxygen in maintaining arterial oxygen saturation and that the use of this device was associated with similar improvements in exercise tolerance to patients taking continuous flow oxygen therapy.
氧疗节省装置可能会大幅延长氧气供应时长。本研究旨在比较脉冲式输氧（PDOD）系统与持续流氧或空气在最大步行试验中的性能。
14例慢性阻塞性肺疾病（COPD）患者，运动时出现动脉血氧饱和度下降（一秒用力呼气量（FEV1）平均（标准差）为0.83（0.28）升，动脉血氧分压（PaO2）为8.38（1.24）kPa，动脉血二氧化碳分压（PaCO2）为5.95（0.86）kPa），被随机分配使用通过气瓶输送的空气、2升/分钟的持续流氧或PDOD系统进行步行试验。
使用PDOD系统或持续流氧时，平均动脉血氧饱和度（SaO2）无显著差异（p = 0.33）。患者使用气瓶步行时血氧饱和度下降最为明显（SaO2为79.2（8.59）%），与使用持续流氧（87.6（5.85）%，p = 0.001）和PDOD（85.6（7.36）%，p = 0.004）时的血氧饱和度下降情况有显著差异。通过持续流氧或PDOD以2升/分钟的流量输氧时，步行距离无显著差异（p = 0.72；可信区间为0.34至1.08）。使用持续流氧（203.6（106.1）米）和PDOD（207.9（109.8）米）时的平均（标准差）步行距离显著长于使用气瓶时的步行距离（188.6（110.02）米）；（距离分别增加1.12倍，可信区间为1.01至1.23，p = 0.02，以及增加1.14倍，可信区间为1.01至1.28，p = 0.03）。
这些发现表明，脉冲式剂量氧疗节省装置在维持动脉血氧饱和度方面与持续流氧一样有效，并且使用该装置与接受持续流氧治疗的患者在运动耐力方面有相似的改善。
