问题 单项选择题 A1/A2型题

男性,57岁,反复咳嗽、咳痰15年伴活动后气短2年,诊断为慢性喘息型支气管炎及阻塞性肺气肿,因病情加重伴呼吸困难、紫绀收入院,在未吸氧时做动脉血气分析,下面结果与其病情相符的是()

A.PaO2正常,PaCO2降低

B.PaO2正常,PaCO2升高

C.PaO2升高,PaCO2正常

D.PaO2升高,PaCO2降低

E.PaO2降低,PaCO2升高

答案

参考答案:E

解析:慢性呼吸衰竭时由于肺泡通气不足、通气/血流比例失调、弥散功能障碍等导致缺氧及二氧化碳潴留。由于氧的弥散力仅为二氧化碳的1/20,所以在病理情况下,弥散障碍主要影响的是氧的交换,出现低氧血症。所以慢阻肺出现呼吸衰竭首先表现为低氧血症,病情进一步加重则可合并二氧化碳潴留。血气分析结果在非吸氧情况下应为动脉血氧分压降低,二氧化碳分压增高,而不应出现氧分压正常或增高结果。

阅读理解

It was a Sunday and the heavy storm had lasted all night. The morning after the storm, though, was beautiful: blue skies, warm air and a calm, inviting sea touching the shore gently.

My father realized it was a good day for fishing and invited my sister and me to go with him. I was only 14 and fishing had never been my thing, but I decided to go all the same. I’m so glad I did.

On the road to the harbour we could see the terrible destruction on the coast, but the harbour itself was in fairly good shape. After all, it was protected by the arms of a bay that had only one tiny channel to the sea. As we got on board, we noticed two big humps(脊背) in the distance.

On approaching them, we saw it was a mother whale with her baby. We couldn’t believe it ——there aren’t any whales along the coast here. The storm must have driven them across the ocean into the bay, in which the still water was so badly polluted that nothing could survive.

The little baby whale——actually as big as our boat——was obviously stuck and could not move. The mother dived under the water and came up suddenly, making big whirlpools(漩涡) and waves. ”She’s trying to help her baby, but on the wrong side, ”my father said. At this point, my father moved our boat in a semicircle to the other side and, heading the boat towards the baby whale, pushed it gently. With our several gentle pushes the big hump turned over and disappeared under water. Then it swam up right beside its mum. They struggled in their desperate attempts to escape but missed the exit and started heading in the wrong direction. We hurried up to the whales and tried to lead them towards the bay channel. Slowly, they let us lead them, some-times rising from the water right beside us to breathe——and to give us a trusting look with those huge eyes. Once they hit their first part of clean water flowing straight from the sea, the mum gave us a wave with her tail and off they swam into the distance.

In the excitement it had felt like only a few minutes, but we had been with those wonderful animals for almost an hour and a half. That was the simple and lasting beauty of the day, Nearly four decades later, I still look back fondly to that golden day at sea.     

小题1:The author says “I’m so glad I did ” (in Para. 2)because ______.

A.he witnessed the whole process of fishing

B.he enjoyed the beauty of the calm sea

C.he experienced the rescue of the whales

D.he spent the weekend with his family小题2:The harbour survived the storm owing to____________.

A.the shape of the harbour

B.the arms of the bay

C.the still water in the channel

D.the long coast line小题3:The mother whale failed to help her baby because__________.

A.she had stayed in the polluted water for too long

B.the whirlpools she had made were not big enough

C.she had no other whales around to turn to for help

D.the waves pushed her baby in the wrong direction小题4:what is the theme of the story?

A.Saving lives brings people a sense of happiness

B.Fishing provides excitement for children

C.It’s necessary to live in harmony with animals

D.It’s vital to protect the environment

单项选择题