Institute for Pulmonary Rehabilitation Research, Schoen Klinik Berchtesgadener Land, Schoenau am Koenigssee, Germany; Department of Prevention, Rehabilitation and Sports Medicine, Technical University of Munich, Munich, Germany.
Institute for Pulmonary Rehabilitation Research, Schoen Klinik Berchtesgadener Land, Schoenau am Koenigssee, Germany.
Respir Med. 2019 Sep;156:26-32. doi: 10.1016/j.rmed.2019.08.001. Epub 2019 Aug 5.
Supplemental oxygen is a recommended therapy option in stable hypoxemic COPD patients. Often, supplemental oxygen is provided by continuous flow (CF). However, demand oxygen delivery systems (DODS) that provide an oxygen bolus only during inspiration have gained increasing use as they prolong oxygen cylinder life (beside battery life). However, there is a lack of evidence if different DODS and CF devices are equivalent.
Seventy hypoxemic COPD patients (FEV 32 ± 9% predicted, PaO 56±7 mmHg) on long-term oxygen therapy were included in this prospective single-blinded, randomized cross-over trial. Following an initial incremental shuttle walk test, patients performed 3 endurance shuttle walk tests (ESWT) at 85% of their maximum walking speed in random order with: (A) CF (ESWT-CF), (B) a DODS based on liquid oxygen (ESWT-DL) and (C) an DODS oxygen concentrator (ESWT-DC). The primary outcome was oxygen saturation (SpO) at ESWT isotime. Secondary outcomes were total ESWT duration, heart rate (HR) and breathing frequency (BF) at isotime and dyspnea at end-exercise.
SpO at ESWT isotime was not clinically different between devices: 90 ± 4% (CF), 89 ± 5% (DL) and 90 ± 5% (DC). However, 20% of the patients showed a ≥4% lower oxygen desaturation while using a DODS device. Secondary outcomes were similar under the three conditions.
Oxygen supplementation via DODS (based on liquid oxygen or as a concentrator) yielded comparable physiological effects during standardized walking in stable hypoxemic COPD patients like CF. However, 20% of patients showed a clinically relevant lower oxygen saturation while using a DODS device. Therefore, we suggest individual testing of oxygen saturation of DODS suitability.
补充氧气是稳定低氧血症 COPD 患者的推荐治疗选择。通常，补充氧气是通过连续流量（CF）提供的。然而，仅在吸气期间提供氧气脉冲的需求氧气输送系统（DODS）已越来越多地被使用，因为它们延长了氧气瓶的使用寿命（除电池寿命外）。然而，缺乏不同的 DODS 和 CF 设备是否等效的证据。
这项前瞻性、单盲、随机交叉试验纳入了 70 名长期接受氧疗的低氧血症 COPD 患者（FEV 32±9%预测值，PaO 56±7mmHg）。在初始递增穿梭步行试验后，患者以随机顺序在 85%最大步行速度下进行 3 次耐力穿梭步行试验（ESWT）：（A）CF（ESWT-CF）、（B）基于液氧的 DODS（ESWT-DL）和（C）DODS 制氧机（ESWT-DC）。主要结局是 ESWT 等时的血氧饱和度（SpO）。次要结局是 ESWT 总持续时间、等时的心率（HR）和呼吸频率（BF）以及运动结束时的呼吸困难。
ESWT 等时的 SpO 在设备之间没有临床差异：90±4%（CF）、89±5%（DL）和 90±5%（DC）。然而，20%的患者在使用 DODS 设备时出现≥4%的更低氧饱和度下降。在三种情况下，次要结局相似。
在稳定低氧血症 COPD 患者进行标准化步行时，DODS（基于液氧或作为浓缩器）供氧产生了类似的生理效应，与 CF 相似。然而，20%的患者在使用 DODS 设备时出现了临床相关的更低氧饱和度。因此，我们建议对 DODS 的氧饱和度适用性进行个体测试。
