Nurse：（bringing all the things needed to the bedside for oxygen therapy）Hi，Mr. Zhao，I’ll give you some oxygen since you are feeling distressed. This will make you feel more comfortable.

护士：（带着准备齐全的吸氧用物来到床边）赵先生，你好，你现在感觉胸闷，我给你吸点氧气，这种治疗会让你舒服一些。

Patient： OK.

病人： 好的。

Nurse：（skillfully setting up the oxygen inhalation therapy system）Mr. Zhao，I have connected the oxygen system for you. How are you feeling now?

护士：（非常熟练地完成了吸氧治疗操作）赵先生，氧气给你接上了，你感觉如何?

Patient：（looking at the fow meter of the oxygen tank）I feel short of breath. Why do you give me so little oxygen?

病人：（看了一眼流量表）我现在气都接不上来，你怎么就给我开一点点氧气。

Nurse： Oh，Mr. Zhao，you do not understand. According to you present condition，you must be given the oxygen in a low fow level. I have adjusted the fow rate for you. You shouldn’t change it by yourself. Please rest. I’ll see you after a while.

护士： 哦，赵先生，你误会了。根据你的病情，你需要低流量吸氧，我已经给你调节好流量了，你可不能自行调节哦。你先休息，过会儿我再来看你。

（One hour later，when the nurse came back，she found that Mr. Zhao had a red face，was talking a lot，and the oxygen fow had been adjusted to 8 liters per minute.）

（一小时后，护士来到床边，发现赵先生面色潮红，多语，氧气流量已被调至8升/分。）

Nurse： Mr. Zhao，what’s the matter with you? Are you OK?（The nurse adjusted the oxygen fow to the previous rate.）

护士： 哦，赵先生，你怎么啦?（护士随手把氧气流量调至原来的刻度。）

Patient： Why am I feeling worse than before?

病人： 我怎么感觉比刚才更糟糕了?

Nurse： You shouldn’t have increase the oxygen fow by yourself. Because your breathing is stimulated by the refex of hypoxia，if you inhale excessive oxygen in a short period of time，hypoxia might be improved transiently，but retention of carbon dioxide will get worse. What we are doing now is called controlled oxygen therapy which can prevent respiratory suppression，correct hypoxia and carbon dioxide retention. Do you understand my explanation?

护士： 你的氧气可不能调高呀。因为你目前的呼吸主要通过缺氧来反射来刺激的。如短时间内吸入过多氧气，虽然缺氧得到短暂改善，但二氧化碳潴留会更加重。我现在给你施行的就是控制性氧疗，这样既可避免呼吸抑制，又可纠正你的缺氧和二氧化碳潴留。我这样解释，你理解吗?

Patient： Oh，I see. I’ll not adjust the oxygen by myself again.

病人： 哦，原来是这样，我懂了。我再也不会自行调节流量了。