问题 单项选择题

室性心动过速伴严重血流动力学障碍时,终止发作的首选方法是()

A.利多卡因

B.胺碘酮

C.同步电复律

D.人工起搏超速抑制

E.压迫颈动脉窦

答案

参考答案:C

解析:室性心动过速如患者已发生低血压、心绞痛、休克、充血性心力衰竭或脑血流灌注不足等症状,应迅速施行电复律。同步电复律能迅速终止室速,改善血流动力学。洋地黄中毒引起的室速,不宜用电复律,应给予药物治疗。持续性室速患者,如病情稳定,可经静脉插入电极导管至右室,应用超速起搏终止心动过速。室速患者如无显著的血流动力学障碍,首先给予静脉注射利多卡因或普鲁卡因胺,同时静脉持续滴注。静脉注射普罗帕酮亦十分有效,但不宜用于心肌梗死或心力衰竭的患者,其他无效时,可选用胺碘酮静脉注射或改用直流电复律。压迫颈动脉窦可用于阵发性室上性心动过速的治疗

阅读理解

阅读理解。

     The common cold is the world's most widespread illness. The most widespread mistake of all is that

colds are caused by cold weather. They are not. They are caused by viruses (病毒) passing on from person

to person. You catch a cold by coming into contact, directly or indirectly, with someone who already has

one.

     If cold weather causes colds, it would be reasonable to expect the Eskimos to suffer from them forever.

But they do not. And in isolated Arctic regions explorers (探险者) have reported being free from colds until

coming into contact again with the outside world by way of packages and mails dropped from airplanes.

During the First World War soldiers who spent long periods in the trenches, cold and wet, showed no

increased tendency to catch colds. In the Second World War prisoners at the notorious Auschwitz

concentration camp, naked and starving, were extremely surprised to find that they seldom had colds.

     At the Common Cold Research Unit in England, volunteers took part in the experiments in which they

gave themselves to the discomforts of being cold and wet for long stretches of time. After taking hot baths,

they put on bathing suits, allowed themselves to be with cold water, and then stood about dripping wet in

drafty rooms. Some wore wet socks all day while others exercised in the rain until close to exhaustion. Not

one of the volunteers came down with a cold unless a cold virus was actually dropped in his nose.

     If, then, cold and wet have nothing to do with catching colds, why are they more frequent (often) in the

winter? Despite the most painstaking research, no one has yet found the answer. One explanation offered by

scientists is that people tend to stay together indoors more in cold weather than at other times, and this makes

it easier for cold viruses to be passed on.

     No one has yet found a cure for colds. There are drugs and pain suppressors such as aspirin, but all they

do is to relieve the symptoms (症状).

1. Are the common colds caused by cold?

    ______________________________________

2. When may Arctic explorers catch colds? 

    ______________________________________

3. How many kinds of people does the writer mention when explaining his idea? 

   ______________________________________

4. Why are the colds more frequent in the winter? 

    ______________________________________

5. What is the key point of this passage? 

    ______________________________________

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